Modified RING finger, HC subclass (C3HC5-type), found in neuralized-like protein 1B (NEURL1B); NEURL1B, also known as neuralized-2 (NEUR2) or neuralized-like protein 3, is a mammalian homolog of the Drosophila neuralized (D-neu) protein. It functions as an E3 ubiquitin-protein ligase that interacts with and ubiquitinates Delta. Thus, it plays a role in the endocytic pathways for Notch signaling through working cooperatively with another E3 ligase, Mind bomb-1 (Mib1), in Delta endocytosis to hepatocyte growth factor-regulated tyrosine kinase substrate (Hrs)-positive vesicles. NEURL1B contains two neuralized homology regions (NHRs) responsible for Neural-ligand interactions and a modified C3HC5-type RING-HC finger required for ubiquitin ligase activity. The C3HC5-type RING-HC finger is distinguished from typical C3HC4-type RING-HC finger due to the existence of the additional cysteine residue in the middle portion of the RING finger domain.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*..
gi 815890918 317 KNGECTVCFDGEVDTVIYTCGHMCLCHSCGLRLKRQARACCPICRRPIKDVIKIYRP 373
Cdd:cd16786    1 KNGECTVCFDSEVDTVIYTCGHMCLCNSCGLKLKRQINACCPICRRVIKDVIKIYRP 57

Modified RING finger, HC subclass (C3HC5-type), found in neuralized-like protein 1B (NEURL1B); NEURL1B, also known as neuralized-2 (NEUR2) or neuralized-like protein 3, is a mammalian homolog of the Drosophila neuralized (D-neu) protein. It functions as an E3 ubiquitin-protein ligase that interacts with and ubiquitinates Delta. Thus, it plays a role in the endocytic pathways for Notch signaling through working cooperatively with another E3 ligase, Mind bomb-1 (Mib1), in Delta endocytosis to hepatocyte growth factor-regulated tyrosine kinase substrate (Hrs)-positive vesicles. NEURL1B contains two neuralized homology regions (NHRs) responsible for Neural-ligand interactions and a modified C3HC5-type RING-HC finger required for ubiquitin ligase activity. The C3HC5-type RING-HC finger is distinguished from typical C3HC4-type RING-HC finger due to the existence of the additional cysteine residue in the middle portion of the RING finger domain.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*..
gi 815890918 317 KNGECTVCFDGEVDTVIYTCGHMCLCHSCGLRLKRQARACCPICRRPIKDVIKIYRP 373
Cdd:cd16786    1 KNGECTVCFDSEVDTVIYTCGHMCLCNSCGLKLKRQINACCPICRRVIKDVIKIYRP 57

Zinc finger, C3HC4 type (RING finger);

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 815890918  317 KNGECTVCFDGEVDTVIYTCGHMCLCHSCGLRLKRQaRACCPICRRPIKDV 367
Cdd:pfam13920   1 EDLLCVICLDRPRNVVLLPCGHLCLCEECAERLLRK-KKKCPICRQPIESV 50

Ring finger; E3 ubiquitin-protein ligase activity is intrinsic to the RING domain of c-Cbl and is likely to be a general function of this domain; Various RING fingers exhibit binding activity towards E2 ubiquitin-conjugating enzymes (Ubc' s)

                           10        20        30        40
                   ....*....|....*....|....*....|....*....|.
gi 815890918   321 CTVCFD-GEVDTVIYTCGHMcLCHSCGLRLKRQARACCPIC 360
Cdd:smart00184   1 CPICLEeYLKDPVILPCGHT-FCRSCIRKWLESGNNTCPIC 40

Modified RING finger, HC subclass (C3HC5-type), found in neuralized-like protein 1B (NEURL1B); NEURL1B, also known as neuralized-2 (NEUR2) or neuralized-like protein 3, is a mammalian homolog of the Drosophila neuralized (D-neu) protein. It functions as an E3 ubiquitin-protein ligase that interacts with and ubiquitinates Delta. Thus, it plays a role in the endocytic pathways for Notch signaling through working cooperatively with another E3 ligase, Mind bomb-1 (Mib1), in Delta endocytosis to hepatocyte growth factor-regulated tyrosine kinase substrate (Hrs)-positive vesicles. NEURL1B contains two neuralized homology regions (NHRs) responsible for Neural-ligand interactions and a modified C3HC5-type RING-HC finger required for ubiquitin ligase activity. The C3HC5-type RING-HC finger is distinguished from typical C3HC4-type RING-HC finger due to the existence of the additional cysteine residue in the middle portion of the RING finger domain.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*..
gi 815890918 317 KNGECTVCFDGEVDTVIYTCGHMCLCHSCGLRLKRQARACCPICRRPIKDVIKIYRP 373
Cdd:cd16786    1 KNGECTVCFDSEVDTVIYTCGHMCLCNSCGLKLKRQINACCPICRRVIKDVIKIYRP 57

domain in neuralized proteins;

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 815890918    97 DLRFHATRGPDVSLSADRKVACAPRPDGGRTLVFSERPLRPGESLFVEVGRPGLAAPGALAFGITSCDPGVLRPNELP-A 175
Cdd:smart00588   2 PLRFHHRHGSNIRLSDSGRVARRSASDFCNALVFSARPLRINELFEVKIEKVVRKWSGALRFGVTTCDPATLRPASLPtN 81

                           90       100       110       120
                   ....*....|....*....|....*....|....*....|..
gi 815890918   176 DPDALLDRKEYWVVARAGPVPSGGDALSFTLRPGGDVLLGIN 217
Cdd:smart00588  82 ACPDLVDMSGFWAKALGEGLAEQGGILGLDVLAEGEVVGVIN 123

Zinc finger, C3HC4 type (RING finger);

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 815890918  317 KNGECTVCFDGEVDTVIYTCGHMCLCHSCGLRLKRQaRACCPICRRPIKDV 367
Cdd:pfam13920   1 EDLLCVICLDRPRNVVLLPCGHLCLCEECAERLLRK-KKKCPICRQPIESV 50

Modified RING finger, HC subclass (C3HC5-type), found in mahogunin RING finger protein 1 (MGRN1), RING finger protein 157 (RNF157) and similar proteins; MGRN1, also known as RING finger protein 156 (RNF156), is a cytosolic E3 ubiquitin-protein ligase that inhibits signaling through the G protein-coupled melanocortin receptors-1 (MC1R), -2 (MC2R) and -4 (MC4R) via ubiquitylation-dependent and -independent processes. It suppresses chaperone-associated misfolded protein aggregation and toxicity. MGRN1 interacts with cytosolic prion proteins (PrPs) that are linked with neurodegeneration. It also interacts with expanded polyglutamine proteins, and suppresses misfolded polyglutamine aggregation and cytotoxicity. Moreover, MGRN1 inhibits melanocortin receptor signaling by competition with Galphas, suggesting a novel pathway for melanocortin signaling from the cell surface to the nucleus. MGRN1 also interacts with and ubiquitylates TSG101, a key component of the endosomal sorting complex required for transport (ESCRT)-I, and regulates endosomal trafficking. A null mutation in the gene encoding MGRN1 causes spongiform neurodegeneration, suggesting a link between dysregulation of endosomal trafficking and spongiform neurodegeneration. RNF157 is a cytoplasmic E3 ubiquitin ligase predominantly expressed in the brain. It is a homolog of the E3 ligase mahogunin ring finger-1 (MGRN1). In cultured neurons, it promotes neuronal survival in an E3 ligase-dependent manner. In contrast, it supports growth and maintenance of dendrites independent of its E3 ligase activity. RNF157 interacts with and ubiquitinates the adaptor protein APBB1 (amyloid beta precursor protein-binding, family B, member 1 or Fe65), which regulates neuronal survival, but not dendritic growth downstream of RNF157. The nuclear localization of APBB1 together with its interaction partner RNA-binding protein SART3 (squamous cell carcinoma antigen recognized by T cells 3 or Tip110) is crucial to trigger apoptosis. Both MGRN1 and RNF157 contain a modified C3HC5-type RING-HC finger, and a functionally uncharacterized region, known as domain associated with RING2 (DAR2), N-terminal to the RING finger. The C3HC5-type RING-HC finger is distinguished from typical C3HC4 RING-HC finger due to the existence of the additional cysteine residue in the middle portion of the RING finger domain.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|...
gi 815890918 319 GECTVCFDGEVDTVIYTCGHMCLCHSCGLRLKRQArACCPICR 361
Cdd:cd16789    1 SECVICLSDPRDTAVLPCRHLCLCSDCAEVLRYQS-NKCPICR 42

SPRY domain in neuralized homology repeat; This family contains the neuralized homology repeat 1 (NHR1) domain similar to the SPRY domain (known to mediate specific protein-protein interactions) at the C-terminus of a conserved region within eukaryotic neuralized and neuralized-like proteins. In Drosophila, the neuralized protein (Neur) belongs to a group of ubiquitin ligases and is required in a subset of Notch pathway-mediated cell fate decisions during development of the nervous system. Neur binds to the Notch receptor ligand Delta through its first NHR1 domain and mediates its ubiquitination for endocytosis. Multiple copies of this region are found in some members of the family.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 815890918  99 RFHATRGPDVSLSADRKVACAPRPDGGRTLVFSERPLRPGEsLF-VEVGR--PGLAapGALAFGITSCDPGVLrpnELPa 175
Cdd:cd12887    1 RFHENHGKNIRLSNDGRTATRVKASFNNGVVFSSRPLRPGE-LFeVRIDKlvDRWS--GSLEIGVTTLNPETL---DLP- 73

                         90
                 ....*....|....*
gi 815890918 176 dPDALLDRKEYWVVA 190
Cdd:cd12887   74 -PSATDLKSGTWILS 87

Modified RING finger, HC subclass (C3HC5-type), found in mitochondrial-anchored protein ligase (MAPL) and similar proteins; MAPL, also known as MULAN, mitochondrial ubiquitin ligase activator of NFKB 1, E3 SUMO-protein ligase MUL1, E3 ubiquitin-protein ligase MUL1, growth inhibition and death E3 ligase (GIDE), putative NF-kappa-B-activating protein 266, or RING finger protein 218 (RNF218), is a multifunctional mitochondrial outer membrane protein involved in several processes specific to metazoan (multicellular animal) cells, such as NF-kappaB activation, innate immunity and antiviral signaling, suppression of PINK1/parkin defects, mitophagy in skeletal muscle, and caspase-dependent apoptosis. MAPL contains a unique BAM (beside a membrane)/GIDE (growth inhibition death E3 ligase) domain and a C-terminal modified cytosolic C3HC5-type RING-HC finger which is distinguished from typical C3HC4-type RING-HC finger due to the existence of the additional cysteine residue in the middle portion of the RING finger domain.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|.
gi 815890918 321 CTVCFDGEVDTVIYTCGHMCLCHSCGLRLKRQARacCPICRRPIKDVIKIY 371
Cdd:cd16648    4 CVICLSNPRSCVFLECGHVCSCIECYEALPSPKK--CPICRSFIKRVVPLY 52

Modified RING finger, HC subclass (C3HC5-type), found in RING finger protein 26 (RNF26) and similar proteins; RNF26 is an E3 ubiquitin ligase that temporally regulates virus-triggered type I interferon induction by increasing the stability of Mediator of IRF3 activation, MITA, also known as STING, through K11-linked polyubiquitination of MITA after viral infection, and promoting the degradation of IRF3, another important component required for virus-triggered interferon induction. Although RNF26 substrates of ubiquitination remain unclear at present, RNF26 upregulation in gastric cancer might be implicated in carcinogenesis through dysregulation of growth regulators. RNF26 contains an N-terminal leucine zipper domain and a C-terminal modified C3HC5-type RING-HC finger, which is distinguished from typical C3HC4 RING-HC finger due to the existence of the additional cysteine residue in the middle portion of the RING finger domain.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|...
gi 815890918 321 CTVCFDGEVDTVIYTCGHMCLCHSCGLRLKRQA--RACCPICRRPIKDVIKIY 371
Cdd:cd16788    8 CVICQDQSKTVLILPCRHMCLCRQCANILLQQPvyRRNCPLCRTMILQTLDVY 60

RING finger, HC subclass, found in RNA-binding proteins of the evolutionarily-conserved MEX-3 family; MEX-3 phosphoproteins are found in vertebrates. They are mediators of post-transcriptional regulation in different organisms, and have been implicated in many core biological processes, including embryonic development, epithelial homeostasis, immune responses, metabolism, and cancer. They contain two K homology (KH) domains that provide RNA-binding capacity, and a C-terminal C3HC4-type RING-HC finger. They shuttle between the nucleus and the cytoplasm via the CRM1-dependent export pathway. The RNA-binding protein MEX-3 from nematode Caenorhabditis elegans is the founding member of the MEX-3 family. Due to the lack of a RING-HC finger, it is not included here.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|..
gi 815890918 320 ECTVCFDGEVDTVIYTCGHMCLCHSCGLRLKRQARACCPICRRPIKDVIKIY 371
Cdd:cd16518    2 DCVVCFESEVVAALVPCGHNLFCMECANRICEKSDPECPVCHTPVTQAIRIF 53

RING finger, HC subclass, found in leucine-rich repeat and sterile alpha motif-containing protein 1 (LRSAM1) and similar proteins; LRSAM1, also known as Tsg101-associated ligase (TAL), or RIFLE, is an E3 ubiquitin-protein ligase that physically associates with, and selectively ubiquitylates, Tsg101, an E2-like molecule that regulates vesicular trafficking processes in yeast and mammals. It regulates a Tsg101-associated complex responsible for the sorting of cargo into cytoplasm-containing vesicles that bud at the multivesicular body and at the plasma membrane. LRSAM1 is a multidomain protein containing an N-terminal leucine-rich repeat (LRR), followed by several recognizable motifs, including an ezrin-radixin-moezin (ERM) domain, a coiled-coil (CC) region, a SAM domain, and a C-terminal C3HC4-type RING-HC finger domain.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|...
gi 815890918 318 NGECTVCFDGEVDTVIYTCGHMCLCHSCGLRLKRqaracCPICRRPIKDVIKI 370
Cdd:cd16515    1 ESECVVCMDAESQVIFLPCGHVCCCQTCSSSLST-----CPLCRADITQRVRI 48

RING finger, HC subclass, found in RING finger and SPRY domain-containing protein 1 (RSPRY1) and similar proteins; RSPRY1 is a hypothetical RING and SPRY domain-containing protein of unknown physiological function. Mutations in its corresponding gene RSPRY1 may associate with a distinct skeletal dysplasia syndrome. RSPRY1 contains a B30.2/SPRY domain and a C3HC4-type RING-HC finger.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....
gi 815890918 321 CTVCFDGEVDTVIYTCGHMCLCHSCGLRLKrqaraCCPICRRPI 364
Cdd:cd16566    5 CTLCFDKVADTELRPCGHSGFCMECALQLE-----TCPLCRQPI 43

RING finger, HC subclass, found in inhibitor of apoptosis proteins (IAPs); IAPs are frequently overexpressed in cancer and associated with tumor cell survival, chemoresistance, disease progression, and poor prognosis. They function primarily as negative regulators of cell death. They regulate caspases and apoptosis through the inhibition of specific members of the caspase family of cysteine proteases. In addition, IAPs has been implicated in a multitude of other cellular processes, including inflammatory signalling and immunity, mitogenic kinase signalling, proliferation and mitosis, as well as cell invasion and metastasis. IAPs in this family includes cellular inhibitor of apoptosis protein c-IAP1 (BIRC2) and c-IAP2 (BIRC3), XIAP (BIRC4), BIRC7, and BIRC8, all of which contain three N-terminal baculoviral IAP repeat (BIR) domains that enable interactions with proteins, a ubiquitin-association (UBA) domain that is responsible for the binding of polyubiquitin (polyUb), and a C3HC4-type RING-HC finger at the carboxyl terminus that is required for ubiquitin ligase activity. The UBA domain is only absent in mammalian homologs of BIRC7. Moreover, c-IAPs contains an additional caspase activation and recruitment domain (CARD) between the UBA and C3HC4-type RING-HC domains. The CARD domain may serve as a protein interaction surface.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|.
gi 815890918 321 CTVCFDGEVDTVIYTCGHMCLCHSCGLRLKRqaracCPICR 361
Cdd:cd16510    4 CKICMDREVNIVFLPCGHLVTCAQCAASLRK-----CPICR 39

Modified RING finger, HC subclass (C3HC5-type), found in cell growth regulator with RING finger domain protein 1 (CGRRF1) and similar proteins; CGRRF1, also known as cell growth regulatory gene 19 protein (CGR19) or RING finger protein 197 (RNF197), functions as a novel biomarker to monitor endometrial sensitivity and response to insulin-sensitizing drugs, such as metformin, in the context of obesity. CGRRF1 contains a C-terminal modified C3HC5-type RING-HC finger, which is distinguished from typical C3HC4 RING-HC finger due to the existence of the additional cysteine residue in the middle portion of the RING finger domain.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|..
gi 815890918 320 ECTVCFDGEVDTVIYTCGHMCLCHSCGLRLKRqaracCPICR 361
Cdd:cd16787    2 DCVVCQNAPVNRVLLPCRHACVCDECFKRLQR-----CPMCR 38

Modified RING finger, HC subclass (C3HC5-type), found in mahogunin RING finger protein 1 (MGRN1) and similar proteins; MGRN1, also known as RING finger protein 156 (RNF156), is a cytosolic E3 ubiquitin-protein ligase that inhibits signaling through the G protein-coupled melanocortin receptors-1 (MC1R), -2 (MC2R) and -4 (MC4R) via ubiquitylation-dependent and -independent processes. It suppresses chaperone-associated misfolded protein aggregation and toxicity. MGRN1 interacts with cytosolic prion proteins (PrPs) that are linked with neurodegeneration. It also interacts with expanded polyglutamine proteins, and suppresses misfolded polyglutamine aggregation and cytotoxicity. Moreover, MGRN1 inhibits melanocortin receptor signaling by competition with Galphas, suggesting a novel pathway for melanocortin signaling from the cell surface to the nucleus. Furthermore, MGRN1 interacts with and ubiquitylates TSG101, a key component of the endosomal sorting complex required for transport (ESCRT)-I, and regulates endosomal trafficking. A null mutation in the gene encoding MGRN1 causes spongiform neurodegeneration, suggesting a link between dysregulation of endosomal trafficking and spongiform neurodegeneration. MGRN1 contains a modified C3HC5-type RING-HC finger, a conserved PSAP motif necessary for interaction between MGRN1 and TSG101. In addition, MGRN1 harbors a functionally uncharacterized region, as known as the domain associated with RING2 (DAR2), N-terminal to the RING finger. The C3HC5-type RING-HC finger is distinguished from typical C3HC4 RING-HC finger due to the existence of the additional cysteine residue in the middle portion of the RING finger domain.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|..
gi 815890918 318 NGECTVCFDGEVDTVIYTCGHMCLCHSCGLRLKRQARAcCPICRRPIKDVIK 369
Cdd:cd16816    8 SNECVVCLSDLRDTLILPCRHLCLCNSCADTLRYQANN-CPICRLPFRALLQ 58

RING finger, HC subclass, found in caspases-8 and -10-associated RING finger protein 1 (CARP1) and similar proteins; CARP1, also known as caspase regulator CARP1, FYVE-RING finger protein Momo, RING finger homologous to inhibitor of apoptosis protein (RFI), RING finger protein 34 (RNF34), or RING finger protein RIFF, is a nuclear protein that functions as a specific E3 ubiquitin ligase for the transcriptional coactivator PGC-1alpha, a master regulator of energy metabolism and adaptive thermogenesis in the brown fat cell which negatively regulates brown fat cell metabolism. It is preferentially expressed in esophageal, gastric, and colorectal cancers, suggesting a possible association with the development of digestive tract cancers. It regulates the p53 signaling pathway by degrading 14-3-3 sigma and stabilizing MDM2. CARP1 does not localize to membranes in the cell and is involved in the negative regulation of apoptosis, specifically targeting two initiator caspases, caspase 8 and caspase 10. CARP1 contains an N-terminal FYVE-like domain and a C-terminal C3HC4-type RING-HC finger domain.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|..
gi 815890918 321 CTVCFDGEVDTVIYTCGHMCLCHSCGLRLKRqaracCPICRRPIKDVIKIYR 372
Cdd:cd16706    7 CRICMDAVIDCVLLECGHMVTCTKCGKRMSE-----CPICRQYVVRAVHVFK 53

RING finger, HC subclass, found in Arabidopsis thaliana MND1-interacting protein 1 (MIP1) and similar proteins; This subfamily includes Arabidopsis thaliana MIP1, RING finger protein 4 (RF4) and RING finger protein 298 (RF298). MIP1 interacts with MND1, HOP2 and XRI1. RF4 and RF298 are putative E3 ubiquitin-protein ligase that may mediate E2-dependent protein ubiquitination. Members of this subfamily contain a typical C3HC4-type RING-HC finger.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|.
gi 815890918 320 ECTVCFDGEVDTVIYTCGHMCLCHSCGLRLKRQARACCPICRRPIKDVIKI 370
Cdd:cd23128    5 ECVMCMEEERSVVFLPCAHQVVCSGCNDLHEKKGMRECPSCRGEIQERIRV 55

RING finger, HC subclass, found in apoptosis protein c-IAP1, c-IAP2, livin, and similar proteins; The cellular inhibitor of apoptosis protein c-IAPs function as ubiquitin E3 ligases that mediate the ubiquitination of substrates involved in apoptosis, nuclear factor-kappaB (NF-kappaB) signaling, and oncogenesis. Unlike other IAPs, such as XIAP, c-IAPs exhibit minimal binding to caspases and may not play an important role in the inhibition of these proteases. c-IAP1, also known as baculoviral IAP repeat-containing protein BIRC2, IAP-2, RING finger protein 48, or TNFR2-TRAF-signaling complex protein 2, is a potent regulator of the tumor necrosis factor (TNF) receptor family and NF-kappaB signaling pathways in the cytoplasm. It can also regulate E2F1 transcription factor-mediated control of cyclin transcription in the nucleus. c-IAP2, also known as BIRC3, IAP-1, apoptosis inhibitor 2 (API2), or IAP homolog C, also influences ubiquitin-dependent pathways that modulate innate immune signalling by activation of NF-kappaB. c-IAPs contain three N-terminal baculoviral IAP repeat (BIR) domains that enable interactions with proteins, a ubiquitin-association (UBA) domain that is responsible for the binding of polyubiquitin (polyUb), a caspase activation and recruitment domain (CARD) that serves as a protein interaction surface, and a C3HC4-type RING-HC finger at the carboxyl terminus that is required for ubiquitin ligase activity. Livin, also known as baculoviral IAP repeat-containing protein 7 (BIRC7), kidney inhibitor of apoptosis protein (KIAP), melanoma inhibitor of apoptosis protein (ML-IAP), or RING finger protein 50, was identified as the melanoma IAP. It plays crucial roles in apoptosis, cell proliferation, and cell cycle control. Its anti-apoptotic activity is regulated by the inhibition of caspase-3, -7, and -9. Its E3 ubiquitin-ligase-like activity promotes degradation of Smac/DIABLO, a critical endogenous regulator of all IAPs. Unlike other family members, mammalian livin contains a single BIR domain and a C3HC4-type RING-HC finger. The UBA domain can be detected in non-mammalian homologs of livin.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|.
gi 815890918 321 CTVCFDGEVDTVIYTCGHMCLCHSCGLRLKRqaracCPICRRPIKDVIKIY 371
Cdd:cd16713   10 CKVCMDKEVSIVFIPCGHLVVCTECAPSLRK-----CPICRATIKGTVRTF 55

RING finger, HC subclass, found in neuralized-like protein 3 (NEURL3) and similar proteins; NEURL3, also known as lung-inducible neuralized-related C3HC4 RING domain protein (LINCR), is a novel inflammation-induced E3 ubiquitin-protein ligase encoded by LINCR, a glucocorticoid-attenuated response gene induced in the lung during endotoxemia. It is expressed in alveolar epithelial type II cells, preferentially interacts with the ubiquitin-conjugating enzyme UbcH6, and generates polyubiquitin chains linked via non-canonical lysine residues. Overexpression of NEURL3 in the developing lung epithelium inhibits distal differentiation and induces cystic changes in the Notch signaling pathway. NEURL3 contains an N-terminal neuralized homology repeat (NHR) domain similar to the SPRY (SPla and the RYanodine receptor) domain and a C-terminal C3HC4-type RING-HC finger.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*...
gi 815890918 320 ECTVCFDGEVDTVIYTCGHMCLCHSCGLRLKRQArACCPICRRPIKDV 367
Cdd:cd16552    3 ECAICFHHTANTRLVPCGHSHFCGSCAWHIFRDT-ARCPVCRWQIEEV 49

RING finger, HC subclass, found in zinc finger protein 598 (ZNF598) and similar proteins; ZNF598 associates with eukaryotic initiation factor 4E (eIF4E) homologous protein from mammals (m4EHP) by binding to Grb10-interacting GYF protein 2 (GIGYF2). The m4EHP-GIGYF2 complex functions as a translational repressor and is essential for normal embryonic development of mammalian. ZNF598 harbors a C3HC4-type RING-HC finger at its N-terminus.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....
gi 815890918 320 ECTVCFDGEVDTVIYTCGHMClCHSCGLRLkrqaRAC-----CPICRRPIKDVI 368
Cdd:cd16615    2 TCVICCEEIEYFAVGPCNHPV-CYKCSLRM----RVLykdkyCPICRTELDKVI 50

RING finger, HC subclass, found in tripartite motif-containing protein TRIM21 and similar proteins; TRIM21, also known as 52 kDa Ro protein, 52 kDa ribonucleoprotein autoantigen Ro/SS-A, Ro(SS-A), RING finger protein 81 (RNF81), or Sjoegren syndrome type A antigen (SS-A), is a ubiquitously expressed E3 ubiquitin-protein ligase and a high affinity antibody receptor uniquely expressed in the cytosol of mammalian cells. As a cytosolic Fc receptor, TRIM21 binds the Fc of virus-associated antibodies and targets the complex in the cytosol for proteasomal degradation in a process known as antibody-dependent intracellular neutralization (ADIN), and provides an intracellular immune response to protect host defense against pathogen infection. It shows remarkably broad isotype specificity as it does not only bind IgG, but also IgM and IgA. Moreover, TRIM21 promotes the cytosolic DNA sensor cGAS and the cytosolic RNA sensor RIG-I sensing of viral genomes during infection by antibody-opsonized virus. It stimulates inflammatory signaling and activates innate transcription factors, such as nuclear factor-kappaB (NF-kappaB). TRIM21 also plays an essential role in p62-regulated redox homeostasis, suggesting it may be a viable target for treating pathological conditions resulting from oxidative damage. Furthermore, TRIM21 may have implications for various autoimmune diseases associated with uncontrolled antiviral signaling through the regulation of Nmi-IFI35 complex-mediated inhibition of innate antiviral response. TRIM21 belongs to the C-IV subclass of the TRIM (tripartite motif) family of proteins that are defined by their N-terminal RBCC (RING, Bbox, and coiled coil) domains, including three consecutive zinc-binding domains, a C3HC4-type RING-HC finger, Bbox1 and Bbox2, and a coiled coil region, as well as a B30.2/SPRY (SplA and ryanodine receptor) domain positioned C-terminal to the RBCC domain.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|...
gi 815890918 321 CTVCFDGEVDTVIYTCGHmCLCHSCGLRLKRQARACCPICRRP 363
Cdd:cd16596   12 CPICLDPFVEPVSIECGH-SFCQECISQVGKGGGSVCPVCRQR 53

Modified RING finger, HC subclass (C2H2C4-type), found in protein MDM4 and similar proteins; MDM4, also known as double minute 4 protein (Hdm4), MDM2-like p53-binding protein, protein MDMX, HDMX, or p53-binding protein MDM4, exerts its oncogenic activity predominantly by binding p53 tumor suppressor and blocking its transcriptional activity. MDM4 is phosphorylated and destabilized in response to DNA damage stress. It can also be specifically dephosphorylated by directly interacting with protein phosphatase 1 (PP1), which may increase its stability and thus inhibit p53 activity. Meanwhile, MDM4 has a p53-independent role in tumorigenesis and cell growth regulation. MDM4 contains an N-terminal p53-binding domain and a C-terminal modified C2H2C4-type RING-HC finger responsible for its hetero-oligomerization, which is crucial for the suppression of P53 activity during embryonic development and the recruitment of E2 ubiquitin-conjugating enzymes. MDM4 also harbors a RanBP2-type zinc finger (zf-RanBP2) domain near the central acidic region.

                         10        20        30
                 ....*....|....*....|....*....|....*
gi 815890918 337 GHMCLCHSCGLRLKRqARACCPICRRPIKDVIKIY 371
Cdd:cd16784   24 AHLVTCFHCARRLKK-AGAPCPVCKKEIQMVIKIF 57

RING finger, HC subclass, found in helicase-like transcription factor (HLTF) and similar proteins; HLTF, also known as DNA-binding protein/plasminogen activator inhibitor 1 regulator, HIP116, RING finger protein 80, SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily A member 3, or sucrose nonfermenting protein 2-like 3, is a yeast RAD5 homolog found in mammals. It has both E3 ubiquitin ligase and DNA helicase activities, and plays a pivotal role in the template-switching pathway of DNA damage tolerance. It is involved in Lys-63-linked poly-ubiquitination of proliferating cell nuclear antigen (PCNA) at Lys-164 and in the regulation of DNA damage tolerance. It shows double-stranded DNA translocase activity with 3'-5' polarity, thereby facilitating regression of the replication fork. HLTF contains an N-terminal HIRAN (HIP116 and RAD5 N-terminal) domain, a SWI/SNF helicase domain that is divided into N- and C-terminal parts by an insertion of a C3HC4-type RING-HC finger involved in the poly-ubiquitination of PCNA.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*.
gi 815890918 320 ECTVCFDGEVDTVIYTCGHMcLCHSCGLRLKRQARACCPICRRPIK 365
Cdd:cd16509    5 ECAICLDSLTNPVITPCAHV-FCRRCICEVIQREKAKCPMCRAPLS 49

RING finger, HC subclass, found in breast cancer type 1 susceptibility protein (BRCA1) and similar proteins; BRCA1, also known as RING finger protein 53 (RNF53), is a RING finger protein encoded by the tumor suppressor gene BRCA1 that regulates all DNA double-strand break (DSB) repair pathways. BRCA1 is frequently mutated in patients with hereditary breast and ovarian cancer (HBOC). Its mutation is also associated with an increased risk of pancreatic, stomach, laryngeal, fallopian tube, and prostate cancer. It plays an important role in the DNA damage response signaling and has been implicated in various cellular processes such as cell cycle regulation, transcriptional regulation, chromatin remodeling, DNA DSBs, and apoptosis. BRCA1 contains an N-terminal C3HC4-type RING-HC finger, and two BRCT (BRCA1 C-terminus domain) repeats at the C-terminus.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|
gi 815890918 317 KNGECTVCFDGEVDTVIYTCGHMcLCHSCGLRL--KRQARACCPICRRPI 364
Cdd:cd16498   15 KNLECPICLELLKEPVSTKCDHQ-FCRFCILKLlqKKKKPAPCPLCKKSV 63

Modified RING finger, HC subclass (C4C4-type), found in Saccharomyces cerevisiae amino acid sensor-independent protein Asi1p, Asi3p and similar proteins; Asi1p and Asi3p are inner nuclear membrane proteins that act as negative regulators of SPS (Ssy1-Ptr3-Ssy5)-sensor signaling in yeast. Together with Asi2p, they assemble into an Asi complex that functions in the SPS amino acid sensing pathway involved in degradation of Stp1 and Stp2 transcription factors. Both Asi1p and Asi3p contain five membrane-spanning domains, as well as highly conserved RING fingers at their extreme C termini, which are C4C4-type RING finger motifs whose overall folding is similar to that of the C3HC4-type RING-HC finger.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|
gi 815890918 321 CTVCFDGEVDTVIYTCGHMCLCHSCGLRLKRQARACCPICRRPIKDVIKI 370
Cdd:cd16616    4 CVICKSNPRNIVLWPCRCLALCDDCRLSLAMRGFHTCVCCRREVKGYSKI 53

second RING finger, HC subclass, found in mind bomb 2 (MIB2) and similar proteins; MIB2, also known as novel zinc finger protein (Novelzin), putative NF-kappa-B-activating protein 002N, skeletrophin, or zinc finger ZZ type with ankyrin repeat domain protein 1, is a large, multi-domain E3 ubiquitin-protein ligase that promotes ubiquitination of the cytoplasmic tails of Notch ligands. Especially, it promotes Delta ubiquitylation and endocytosis in Notch activation. Overexpression of MIB2, activates NF-kappaB and interferon-stimulated response element (ISRE) reporter activity. Moreover, MIB2 acts as a novel component of the activated B-cell CLL/lymphoma 10 (BCL10) complex and controls BCL10-dependent NF-kappaB activation. It also functions as a founder myoblast-specific protein that regulates myoblast fusion and muscle stability. MIB2 contains an MZM region with two Mib-Herc2 domains flanking a ZZ zinc finger, a REP region including two tandem Mib repeats, an ANK region that spans ankyrin repeats, and a RNG region consisting of two C3HC4-type RING-HC fingers. This model corresponds to the second RING-HC finger.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|.
gi 815890918 321 CTVCFDGEVDTViYTCGHMClCHSCGLRLKrqaraCCPICRRPIKDVIKIY 371
Cdd:cd16728    7 CPICIDNHIKLV-FQCGHGS-CIECSSALK-----ACPICRQAIRERIQIF 50

Ring finger domain;

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*
gi 815890918  320 ECTVC---FDGEVDTVIYTCGHmCLCHSCGLRLKRQARaCCPICR 361
Cdd:pfam13639   2 ECPICleeFEEGDKVVVLPCGH-HFHRECLDKWLRSSN-TCPLCR 44

Modified RING finger, HC subclass (C2H2C4-type), found in E3 ubiquitin-protein ligase MDM2 and similar proteins; MDM2, also known as double minute 2 protein (Hdm2), oncoprotein MDM2, or p53-binding protein, exerts its oncogenic activity predominantly by binding p53 tumor suppressor and blocking its transcriptional activity. It forms homo-oligomers and displays E3 ubiquitin ligase activity that catalyzes the attachment of ubiquitin to p53 as an essential step in the regulation of its levels in cells. Moreover, in response to ribosomal stress, MDM2-mediated p53 ubiquitination and degradation can be inhibited through its interaction with ribosomal proteins L5, L11, and L23. MDM2 can be phosphorylated in the DNA damage. Meanwhile, MDM2 has a p53-independent role in tumorigenesis and cell growth regulation. In addition, it binds interferon (IFN) regulatory factor-2 (IRF-2), an IFN-regulated transcription factor, and mediates its ubiquitination. MDM2 contains an N-terminal p53-binding domain, and a C-terminal modified C2H2C4-type RING-HC finger conferring E3 ligase activity that is required for ubiquitination and nuclear export of p53. It is also responsible for the hetero-oligomerization of MDM2, which is crucial for the suppression of P53 activity during embryonic development, and the recruitment of E2 ubiquitin-conjugating enzymes. MDM2 also harbors a RanBP2-type zinc finger (zf-RanBP2) domain, as well as a nuclear localization signal (NLS) and a nuclear export signal (NES), near the central acidic region. The zf-RanBP2 domain plays an important role in mediating MDM2 binding to ribosomal proteins and thus is involved in MDM2-mediated p53 suppression.

                         10        20        30
                 ....*....|....*....|....*....|....*..
gi 815890918 337 GHMCLCHSCGLRLKRQARACcPICRRPIKDVIKIYRP 373
Cdd:cd16783   22 GHLMACFTCAKKLKKRNKPC-PVCRQPIQMIVLTYFP 57

RING finger, HC subclass, found in seven in absentia homolog 2 (SIAH2) and similar proteins; SIAH2 is an E3 ubiquitin-protein ligase that contributes to proteasome-mediated degradation of multiple targets in numerous cellular processes. It targets the ubiquitylation and degradation of tumor necrosis factor receptor-associated factor 2 (TRAF2) under stress conditions, which is required for the cell to commit to undergoing apoptosis. It is, therefore, a key regulator of TRAF2-dependent signaling in response to tumor necrosis factor-alpha (TNF-alpha) treatment and UV irradiation. SIAH2 modulates the polyubiquitination of G protein pathway suppressor 2 (GPS2), and targets it for proteasomal degradation. It is also a regulator of NF-E2-related factor 2 (Nrf2), a key regulator of cellular oxidative response, and contributes to the degradation of Nrf2 irrespective of its phosphorylation status. Moreover, SIAH2 contributes to castration-resistant prostate cancer (CRPC) by regulation of androgen receptor (AR) transcriptional activity. It enhances AR transcriptional activity and prostate cancer cell growth. Its stability can be regulated by AKR1C3. SIAH2 also inhibits tyrosine kinase-2 (TYK2)-STAT3 signaling in lung carcinoma cells. Furthermore, SIAH2 regulates obesity-induced adipose tissue inflammation by altering peroxisome proliferator-activated receptor gamma (PPAR gamma) protein levels and selectively regulating PPAR gamma activity. It also functions as a regulator of the nuclear hormone receptor RevErbalpha (Nr1d1) stability and rhythmicity, and overall circadian oscillator function. In addition, SIAH2 is an essential component of the hypoxia response Hippo signaling pathway and has been implicated in normal development and tumorigenesis. It modulates the hypoxia pathway upstream of hypoxia-induced transcription factor subunit HIF-1alpha, and therefore may play an important role in angiogenesis in response to hypoxic stress in endothelial cells. It also stimulates transcriptional coactivator YAP1 by destabilizing serine/threonine-protein kinase LATS2, a critical component of the Hippo pathway, in response to hypoxia. Meanwhile, SIAH2 is involved in regulation of tight junction integrity and cell polarity under hypoxia, through its regulation of apoptosis-stimulating proteins of p53 subunit 2 (ASPP2) stability. SIAH2 contains an N-terminal C3HC4-type RING-HC finger, two zinc-finger subdomains, and a C-terminal tumor necrosis factor (TNF) receptor associated factor (TRAF)-like substrate-binding domain (SBD) responsible for dimer formation.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|
gi 815890918 320 ECTVCFDGEVDTVIYTCGHMCLCHSCglrlkRQARACCPICRRPIKDVIK 369
Cdd:cd16752    5 ECPVCFDYVLPPILQCQAGHLVCNQC-----RQKLSCCPTCRGPLTPSIR 49

RING finger, HC subclass, found in yeast Bre1 and its homologs from eukaryotes; Bre1 is an E3 ubiquitin-protein ligase that catalyzes monoubiquitination of histone H2B in concert with the E2 ubiquitin-conjugating enzyme, Rad6. The Rad6-Bre1-mediated histone H2B ubiquitylation modulates the formation of double-strand breaks (DSBs) during meiosis in yeast. it is also required, indirectly, for the methylation of histone 3 on lysine 4 (H3K4) and 79. RNF20, also known as BRE1A and RNF40, also known as BRE1B, are the mammalian homologs of Bre1. They work together to form a heterodimeric Bre1 complex that facilitate the K120 monoubiquitination of histone H2B (H2Bub1), a DNA damage-induced histone modification that is crucial for recruitment of the chromatin remodeler SNF2h to DNA double-strand break (DSB) damage sites. Moreover, the Bre1 complex acts as a tumor suppressor, augmenting expression of select tumor suppressor genes and suppressing select oncogenes. Deficiency in the mammalian histone H2B ubiquitin ligase Bre1 leads to replication stress and chromosomal instability. All subfamily members contain a C3HC4-type RING-HC finger at its C-terminus.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|...
gi 815890918 321 CTVCFDGEVDTVIYTCGHMcLCHSC-GLRLKRQARAcCPICRRPI--KDVIKI 370
Cdd:cd16499    9 CSVCNDRFKDVIITKCGHV-FCNECvQKRLETRQRK-CPGCGKAFgaNDVQRI 59

first RING finger, HC subclass, found in mind bomb 1 (MIB1) and similar proteins; MIB1, also known as DAPK-interacting protein 1 (DIP-1) or zinc finger ZZ type with ankyrin repeat domain protein 2, is a large, multi-domain E3 ubiquitin-protein ligase that promotes ubiquitination of the cytoplasmic tails of Notch ligands, and thus plays an essential role in controlling metazoan development by Notch signaling. It is also involved in Wnt/beta-catenin signaling and nuclear factor (NF)-kappaB signaling, and has been implicated in innate immunity, neuronal function, genomic stability, and cell death. MIB1 contains an MZM region with two Mib-Herc2 domains flanking a ZZ zinc finger, a REP region including two tandem Mib repeats, an ANK region that spans ankyrin repeats, and a RNG region consisting of three C3HC4-type RING-HC fingers. This model corresponds to the first RING-HC finger.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|..
gi 815890918 320 ECTVCFDGEVDTVIYTCGHMCLCHSCGLRLKRqaracCPICR 361
Cdd:cd16724    2 ECMVCSDMKRDTLFGPCGHIATCSLCSPRVKK-----CLICK 38

RING finger, HC subclass, found in tripartite motif-containing proteins, TRIM7, TRIM11 and TRIM27, and similar proteins; TRIM7, TRIM11 and TRIM27, closely related tripartite motif-containing proteins, belong to the C-IV subclass of the TRIM (tripartite motif) family of proteins that are defined by their N-terminal RBCC (RING, Bbox, and coiled coil) domains, including three consecutive zinc-binding domains, a C3HC4-type RING-HC finger, Bbox2, and a coiled coil region, as well as a SPRY/B30.2 domain positioned C-terminal to the RBCC domain. TRIM7, also known as glycogenin-interacting protein (GNIP) or RING finger protein 90 (RNF90), is an E3 ubiquitin-protein ligase that mediates c-Jun/AP-1 activation by Ras signalling. Its phosphorylation and activation by MSK1 in response to direct activation by the Ras-Raf-MEK-ERK pathway can stimulate TRIM7 E3 ubiquitin ligase activity in mediating Lys63-linked ubiquitination of the AP-1 coactivator RACO-1, leading to RACO-1 protein stabilization. Moreover, TRIM7 binds and activates glycogenin, the self-glucosylating initiator of glycogen biosynthesis. TRIM11, also known as protein BIA1, or RING finger protein 92 (RNF92), is an E3 ubiquitin-protein ligase involved in the development of the central nervous system. It is overexpressed in high-grade gliomas and promotes proliferation, invasion, migration and glial tumor growth. TRIM11 acts as a potential therapeutic target for congenital central hypoventilation syndrome (CCHS) by mediating the degradation of CCHS-associated polyalanine-expanded Phox2b. TRIM11 modulates the function of neurogenic transcription factor Pax6 through the ubiquitin-proteosome system, and thus plays an essential role for Pax6-dependent neurogenesis. It also binds to and destabilizes a key component of the activator-mediated cofactor complex (ARC105), humanin, a neuroprotective peptide against Alzheimer's disease-relevant insults, and further regulates ARC105 function in transforming growth factor beta (TGFbeta) signaling. Moreover, TRIM11 negatively regulates retinoic acid-inducible gene-I (RIG-I)-mediated interferon-beta (IFNbeta) production and antiviral activity by targeting TANK-binding kinase-1 (TBK1). It may contribute to the endogenous restriction of retroviruses in cells. It enhances N-tropic murine leukemia virus (N-MLV) entry by interfering with Ref1 restriction. It also suppresses the early steps of human immunodeficiency virus HIV-1 transduction, resulting in decreased reverse transcripts. TRIM27, also known as RING finger protein 76 (RNF76), RET finger protein (RFP), or zinc finger protein RFP, is a nuclear E3 ubiquitin-protein ligase that is highly expressed in testis and in various tumor cell lines. Expression of TRIM27 is associated with prognosis of colon and endometrial cancers. TRIM27 was first identified as a fusion partner of the RET receptor tyrosine kinase. It functions as a transcriptional repressor and associates with several proteins involved in transcriptional activity, such as enhancer of polycomb 1 (Epc1), a member of the Polycomb group proteins, and Mi-2beta, a main component of the nucleosome remodeling and deacetylase (NuRD) complex, and the cell cycle regulator retinoblastoma protein (RB1). It also interacts with HDAC1, leading to downregulation of thioredoxin binding protein 2 (TBP-2), which inhibits the function of thioredoxin. Moreover, TRIM27 mediates Pax7-induced ubiquitination of MyoD in skeletal muscle atrophy. In addition, it inhibits muscle differentiation by modulating serum response factor (SRF) and Epc1. TRIM27 promotes a non-canonical polyubiquitination of PTEN, a lipid phosphatase that catalyzes PtdIns(3,4,5)P3 (PIP3) to PtdIns(4,5)P2 (PIP2). It is an IKKepsilon-interacting protein that regulates IkappaB kinase (IKK) function and negatively regulates signaling involved in the antiviral response and inflammation. TRIM27 also forms a protein complex with MBD4 or MBD2 or MBD3, and thus plays an important role in the enhancement of transcriptional repression through MBD proteins in tumorigenesis, spermatogenesis, and embryogenesis. It is a component of an estrogen receptor 1 (ESR1) regulatory complex that is involved in estrogen receptor-mediated transcription in MCF-7 cells.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*
gi 815890918 321 CTVCFDGEVDTVIYTCGHMcLCHSCGLRL--KRQARACCPICRRP 363
Cdd:cd16594    8 CPICLDYFTDPVTLDCGHS-FCRACIARCweEPETSASCPQCRET 51

RING finger, HC subclass, found in RING domain ligase RGLG1, RGLG2 and similar proteins from plant; RGLG1 is a ubiquitously expressed E3 ubiquitin-protein ligase that interacts with UBC13 and, together with UBC13, catalyzes the formation of K63-linked polyubiquitin chains, which is involved in DNA damage repair. RGLG1 mediates the formation of canonical, K48-linked polyubiquitin chains that target proteins for degradation. It also regulates apical dominance by acting on the auxin transport proteins abundance. RGLG1 has overlapping functions with its closest sequelog, RGLG2. They both function as RING E3 ligases that interact with ethylene response factor 53 (ERF53) in the nucleus and negatively regulate the plant drought stress response. Members of this subfamily contain a Von Willebrand factor type A (vWA) domain and a C3HC4-type RING-HC finger.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|..
gi 815890918 320 ECTVCFDGEVDtVIYTCGHMClCHSCGLRLKRqaracCPICRRPIKDVIKIY 371
Cdd:cd16729    4 LCPICLSNPKD-MAFGCGHQT-CCECGQSLTH-----CPICRQPITTRIKLY 48

RING finger, HC subclass, found in E3 ubiquitin-protein ligase Cbl-c and similar proteins; Cbl-c, also known as RING finger protein 57 (RNF57), SH3-binding protein Cbl-3, SH3-binding protein Cbl-c, or signal transduction protein Cbl-c, is an E3 ubiquitin-protein ligase expressed exclusively in epithelial cells. It contains a tyrosine-kinase-binding domain (TKB, also known as the phosphotyrosine binding PTB domain, composed of a four helix-bundle, a Ca2+ binding EF-hand and a highly variant SH2 domain), a C3HC4-type RING-HC finger, and a short proline-rich region, but lacks the ubiquitin-associated (UBA) leucine zipper motif that are present in Cbl and Cbl-b. Cbl-c acts as a regulator of epidermal growth factor receptor (EGFR)-mediated signal transduction. It also suppresses v-Src-induced transformation through ubiquitin-dependent protein degradation. Moreover, Cbl-c ubiquitinates and downregulates RETMEN2A and implicates Enigma (PDLIM7) as a positive regulator of RETMEN2A by blocking Cbl-mediated ubiquitination and degradation. The ubiquitin ligase activity of Cbl-c is increased via the interaction of its RING-HC finger domain with a LIM domain of the paxillin homolog, hydrogen peroxide induced construct 5 (Hic-5).

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*
gi 815890918 321 CTVCFDGEVDTVIYTCGHMcLCHSCGLRLKRQARACCPICRRPIK 365
Cdd:cd16710   16 CKICAERDKDVRIEPCGHL-LCSCCLAAWQHSDSQTCPFCRCEIK 59