First immunoglobulin (Ig)-like domain of carcinoembryonic antigen (CEA) related cell adhesion molecule (CEACAM); The members here are composed of the immunoglobulin (Ig)-like domain 1 in carcinoembryonic antigen (CEA) related cell adhesion molecule (CEACAM) proteins. The CEA family is a group of anchored or secreted glycoproteins, expressed by epithelial cells, leukocytes, endothelial cells, and placenta. The CEA family is divided into the CEACAM and pregnancy-specific glycoprotein (PSG) subfamilies. This group represents the CEACAM subfamily. CEACAM1 has many important cellular functions: it is a cell adhesion molecule and a signaling molecule that regulates the growth of tumor cells, an angiogenic factor, and a receptor for bacterial and viral pathogens, including mouse hepatitis virus (MHV). In mice, four isoforms of CEACAM1 generated by alternative splicing have either two (D1, D4) or four (D1-D4) Ig-like domains on the cell surface.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 254692835 273 LSIDPVPQHAAEGGSVLLQVYNLPEGLQTFSWYKGVLSTQDFKIAEYSIATKSIIRGRAHSRREIGYTNGSLLLQDVTEK 352
Cdd:cd05774    1 LTIELVPPQVAEGENVLLLVHNLPENLLAYAWYKGKTVSPNFLIASYIISTNSSTPGPAYSGRETIYPNGSLLIQNVTQK 80

                         90       100
                 ....*....|....*....|....*
gi 254692835 353 DSGLYTLVTIDSNMRVVTAHVQVNI 377
Cdd:cd05774   81 DTGFYTLQTITADLQTEQASVHLQV 105

First immunoglobulin (Ig)-like domain of carcinoembryonic antigen (CEA) related cell adhesion molecule (CEACAM); The members here are composed of the immunoglobulin (Ig)-like domain 1 in carcinoembryonic antigen (CEA) related cell adhesion molecule (CEACAM) proteins. The CEA family is a group of anchored or secreted glycoproteins, expressed by epithelial cells, leukocytes, endothelial cells, and placenta. The CEA family is divided into the CEACAM and pregnancy-specific glycoprotein (PSG) subfamilies. This group represents the CEACAM subfamily. CEACAM1 has many important cellular functions: it is a cell adhesion molecule and a signaling molecule that regulates the growth of tumor cells, an angiogenic factor, and a receptor for bacterial and viral pathogens, including mouse hepatitis virus (MHV). In mice, four isoforms of CEACAM1 generated by alternative splicing have either two (D1, D4) or four (D1-D4) Ig-like domains on the cell surface.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 254692835  36 VTIESFPPQVVEGENVLLRVDNMPENLLVFGWYRGMTNL-RHAIALYYSLT---AKGLKHSGRETLYINGSLWIQNVTQE 111
Cdd:cd05774    1 LTIELVPPQVAEGENVLLLVHNLPENLLAYAWYKGKTVSpNFLIASYIISTnssTPGPAYSGRETIYPNGSLLIQNVTQK 80

                         90       100
                 ....*....|....*....|....*.
gi 254692835 112 DTGYYTFQTISKQGEmVSNTSLYLHV 137
Cdd:cd05774   81 DTGFYTLQTITADLQ-TEQASVHLQV 105

First immunoglobulin (Ig)-like domain of carcinoembryonic antigen (CEA) related cell adhesion molecule (CEACAM); The members here are composed of the immunoglobulin (Ig)-like domain 1 in carcinoembryonic antigen (CEA) related cell adhesion molecule (CEACAM) proteins. The CEA family is a group of anchored or secreted glycoproteins, expressed by epithelial cells, leukocytes, endothelial cells, and placenta. The CEA family is divided into the CEACAM and pregnancy-specific glycoprotein (PSG) subfamilies. This group represents the CEACAM subfamily. CEACAM1 has many important cellular functions: it is a cell adhesion molecule and a signaling molecule that regulates the growth of tumor cells, an angiogenic factor, and a receptor for bacterial and viral pathogens, including mouse hepatitis virus (MHV). In mice, four isoforms of CEACAM1 generated by alternative splicing have either two (D1, D4) or four (D1-D4) Ig-like domains on the cell surface.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 254692835 273 LSIDPVPQHAAEGGSVLLQVYNLPEGLQTFSWYKGVLSTQDFKIAEYSIATKSIIRGRAHSRREIGYTNGSLLLQDVTEK 352
Cdd:cd05774    1 LTIELVPPQVAEGENVLLLVHNLPENLLAYAWYKGKTVSPNFLIASYIISTNSSTPGPAYSGRETIYPNGSLLIQNVTQK 80

                         90       100
                 ....*....|....*....|....*
gi 254692835 353 DSGLYTLVTIDSNMRVVTAHVQVNI 377
Cdd:cd05774   81 DTGFYTLQTITADLQTEQASVHLQV 105

First immunoglobulin (Ig)-like domain of carcinoembryonic antigen (CEA) related cell adhesion molecule (CEACAM); The members here are composed of the immunoglobulin (Ig)-like domain 1 in carcinoembryonic antigen (CEA) related cell adhesion molecule (CEACAM) proteins. The CEA family is a group of anchored or secreted glycoproteins, expressed by epithelial cells, leukocytes, endothelial cells, and placenta. The CEA family is divided into the CEACAM and pregnancy-specific glycoprotein (PSG) subfamilies. This group represents the CEACAM subfamily. CEACAM1 has many important cellular functions: it is a cell adhesion molecule and a signaling molecule that regulates the growth of tumor cells, an angiogenic factor, and a receptor for bacterial and viral pathogens, including mouse hepatitis virus (MHV). In mice, four isoforms of CEACAM1 generated by alternative splicing have either two (D1, D4) or four (D1-D4) Ig-like domains on the cell surface.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 254692835  36 VTIESFPPQVVEGENVLLRVDNMPENLLVFGWYRGMTNL-RHAIALYYSLT---AKGLKHSGRETLYINGSLWIQNVTQE 111
Cdd:cd05774    1 LTIELVPPQVAEGENVLLLVHNLPENLLAYAWYKGKTVSpNFLIASYIISTnssTPGPAYSGRETIYPNGSLLIQNVTQK 80

                         90       100
                 ....*....|....*....|....*.
gi 254692835 112 DTGYYTFQTISKQGEmVSNTSLYLHV 137
Cdd:cd05774   81 DTGFYTLQTITADLQ-TEQASVHLQV 105

Immunoglobulin V-set domain; This domain is found in antibodies as well as neural protein P0 and CTL4 amongst others.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 254692835  275 IDPVPQHAAEGGSVLLQVYNLP---EGLQTFSWYKGVLSTQ-DFKIAEYSI-ATKSIIRGRAHSRREIGYTNGSLLLQDV 349
Cdd:pfam07686   1 QTPREVTVALGGSVTLPCTYSSsmsEASTSVYWYRQPPGKGpTFLIAYYSNgSEEGVKKGRFSGRGDPSNGDGSLTIQNL 80

                          90       100
                  ....*....|....*....|....*....
gi 254692835  350 TEKDSGLYTLVTIDSNMRVVTAHVQVNIH 378
Cdd:pfam07686  81 TLSDSGTYTCAVIPSGEGVFGKGTRLTVL 109

Immunoglobulin V-set domain; This domain is found in antibodies as well as neural protein P0 and CTL4 amongst others.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 254692835   42 PPQVVEGENVLLRV---DNMPENLLVFGWYRGMT--NLRHAIALYYSLTAKGLK---HSGRETL-YINGSLWIQNVTQED 112
Cdd:pfam07686   5 EVTVALGGSVTLPCtysSSMSEASTSVYWYRQPPgkGPTFLIAYYSNGSEEGVKkgrFSGRGDPsNGDGSLTIQNLTLSD 84

                          90       100
                  ....*....|....*....|....*.
gi 254692835  113 TGYYTFQTISKqGEMVSNTSLYLHVY 138
Cdd:pfam07686  85 SGTYTCAVIPS-GEGVFGKGTRLTVL 109

Immunoglobulin I-set domain;

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 254692835  390 DSTVRVQSSVVFTCfsYNTG---ISIRWLFNNQNLQLTER--MTLSPSKCQLRIHTVRKEDAGEYQCEAFNPVSSKTSlP 464
Cdd:pfam07679   9 DVEVQEGESARFTC--TVTGtpdPEVSWFKDGQPLRSSDRfkVTYEGGTYTLTISNVQPDDSGKYTCVATNSAGEAEA-S 85

                  ....*
gi 254692835  465 VRLTV 469
Cdd:pfam07679  86 AELTV 90

Immunoglobulin like; IG domains that cannot be classified into one of IGv1, IGc1, IGc2, IG.

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 254692835   277 PVPQHAAEGGSVLLQVYNLPEGLQTFSWYKgvlstQDFKIAEYSiatksiirGRAHSRREigYTNGSLLLQDVTEKDSGL 356
Cdd:smart00410   1 PPSVTVKEGESVTLSCEASGSPPPEVTWYK-----QGGKLLAES--------GRFSVSRS--GSTSTLTISNVTPEDSGT 65

                           90       100
                   ....*....|....*....|
gi 254692835   357 YT-LVTIDSNMRVVTAHVQV 375
Cdd:smart00410  66 YTcAATNSSGSASSGTTLTV 85

First immunoglobulin (Ig)-like domain of carcinoembryonic antigen (CEA) related cell adhesion molecule (CEACAM); The members here are composed of the immunoglobulin (Ig)-like domain 1 in carcinoembryonic antigen (CEA) related cell adhesion molecule (CEACAM) proteins. The CEA family is a group of anchored or secreted glycoproteins, expressed by epithelial cells, leukocytes, endothelial cells, and placenta. The CEA family is divided into the CEACAM and pregnancy-specific glycoprotein (PSG) subfamilies. This group represents the CEACAM subfamily. CEACAM1 has many important cellular functions: it is a cell adhesion molecule and a signaling molecule that regulates the growth of tumor cells, an angiogenic factor, and a receptor for bacterial and viral pathogens, including mouse hepatitis virus (MHV). In mice, four isoforms of CEACAM1 generated by alternative splicing have either two (D1, D4) or four (D1-D4) Ig-like domains on the cell surface.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 254692835 273 LSIDPVPQHAAEGGSVLLQVYNLPEGLQTFSWYKGVLSTQDFKIAEYSIATKSIIRGRAHSRREIGYTNGSLLLQDVTEK 352
Cdd:cd05774    1 LTIELVPPQVAEGENVLLLVHNLPENLLAYAWYKGKTVSPNFLIASYIISTNSSTPGPAYSGRETIYPNGSLLIQNVTQK 80

                         90       100
                 ....*....|....*....|....*
gi 254692835 353 DSGLYTLVTIDSNMRVVTAHVQVNI 377
Cdd:cd05774   81 DTGFYTLQTITADLQTEQASVHLQV 105

First immunoglobulin (Ig)-like domain of carcinoembryonic antigen (CEA) related cell adhesion molecule (CEACAM); The members here are composed of the immunoglobulin (Ig)-like domain 1 in carcinoembryonic antigen (CEA) related cell adhesion molecule (CEACAM) proteins. The CEA family is a group of anchored or secreted glycoproteins, expressed by epithelial cells, leukocytes, endothelial cells, and placenta. The CEA family is divided into the CEACAM and pregnancy-specific glycoprotein (PSG) subfamilies. This group represents the CEACAM subfamily. CEACAM1 has many important cellular functions: it is a cell adhesion molecule and a signaling molecule that regulates the growth of tumor cells, an angiogenic factor, and a receptor for bacterial and viral pathogens, including mouse hepatitis virus (MHV). In mice, four isoforms of CEACAM1 generated by alternative splicing have either two (D1, D4) or four (D1-D4) Ig-like domains on the cell surface.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 254692835  36 VTIESFPPQVVEGENVLLRVDNMPENLLVFGWYRGMTNL-RHAIALYYSLT---AKGLKHSGRETLYINGSLWIQNVTQE 111
Cdd:cd05774    1 LTIELVPPQVAEGENVLLLVHNLPENLLAYAWYKGKTVSpNFLIASYIISTnssTPGPAYSGRETIYPNGSLLIQNVTQK 80

                         90       100
                 ....*....|....*....|....*.
gi 254692835 112 DTGYYTFQTISKQGEmVSNTSLYLHV 137
Cdd:cd05774   81 DTGFYTLQTITADLQ-TEQASVHLQV 105

Immunoglobulin (Ig)-like domain of carcinoembryonic antigen (CEA) related cell adhesion molecule (CEACAM) and similar proteins; The members here are composed of the immunoglobulin (Ig)-like domain in carcinoembryonic antigen (CEA) related cell adhesion molecule (CEACAM) and related domains. The CEA family is a group of anchored or secreted glycoproteins, expressed by epithelial cells, leukocytes, endothelial cells and placenta. The CEA family is divided into the CEACAM and pregnancy-specific glycoprotein (PSG) subfamilies. This group represents the CEACAM subfamily. CEACAM1 has many important cellular functions: it is a cell adhesion molecule and a signaling molecule that regulates the growth of tumor cells, an angiogenic factor, and a receptor for bacterial and viral pathogens, including mouse hepatitis virus (MHV). In mice, four isoforms of CEACAM1 generated by alternative splicing have either two (D1, D4) or four (D1-D4) Ig-like domains on the cell surface. This family corresponds to the D1 Ig-like domain. Also belonging to this group is the N-terminal immunoglobulin (Ig)-like domain of the signaling lymphocyte activation molecule (SLAM) family, CD84-like family. The SLAM family is a group of immune-cell specific receptors that can regulate both adaptive and innate immune responses. SLAM family proteins are organized as an extracellular domain with having two or four Ig-like domains, a single transmembrane segment, and a cytoplasmic region having Tyr-based motifs. The extracellular domain is organized as a membrane-distal Ig variable (IgV) domain that is responsible for ligand recognition and a membrane-proximal truncated Ig constant-2 (IgC2) domain.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 254692835 161 SVAAGGSVLLLVHNIPKYLQSLFWYKGLIVFNKVEIARYRRAKKSREPGPAHSGRETVYRNGSLLLKNVTWKDTGFYTLR 240
Cdd:cd05741    6 YGAEGKNVLLLVPNLQTPLKSVSWYKGKQVSRNDEIAEYENSSDEFRAGSAFSGREYIYTNGSLLIQNITLSDTGFYTLE 85

                         90
                 ....*....|....*..
gi 254692835 241 TLTRYQKMELAHIYLQV 257
Cdd:cd05741   86 STNIGGKTESATFQLHV 102

Immunoglobulin (Ig)-like domain of carcinoembryonic antigen (CEA) related cell adhesion molecule (CEACAM) and similar proteins; The members here are composed of the immunoglobulin (Ig)-like domain in carcinoembryonic antigen (CEA) related cell adhesion molecule (CEACAM) and related domains. The CEA family is a group of anchored or secreted glycoproteins, expressed by epithelial cells, leukocytes, endothelial cells and placenta. The CEA family is divided into the CEACAM and pregnancy-specific glycoprotein (PSG) subfamilies. This group represents the CEACAM subfamily. CEACAM1 has many important cellular functions: it is a cell adhesion molecule and a signaling molecule that regulates the growth of tumor cells, an angiogenic factor, and a receptor for bacterial and viral pathogens, including mouse hepatitis virus (MHV). In mice, four isoforms of CEACAM1 generated by alternative splicing have either two (D1, D4) or four (D1-D4) Ig-like domains on the cell surface. This family corresponds to the D1 Ig-like domain. Also belonging to this group is the N-terminal immunoglobulin (Ig)-like domain of the signaling lymphocyte activation molecule (SLAM) family, CD84-like family. The SLAM family is a group of immune-cell specific receptors that can regulate both adaptive and innate immune responses. SLAM family proteins are organized as an extracellular domain with having two or four Ig-like domains, a single transmembrane segment, and a cytoplasmic region having Tyr-based motifs. The extracellular domain is organized as a membrane-distal Ig variable (IgV) domain that is responsible for ligand recognition and a membrane-proximal truncated Ig constant-2 (IgC2) domain.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 254692835  37 TIESFppQVVEGENVLLRVDNMPENLLVFGWYRG-MTNLRHAIALYYSLTAK---GLKHSGRETLYINGSLWIQNVTQED 112
Cdd:cd05741    1 SSEQF--YGAEGKNVLLLVPNLQTPLKSVSWYKGkQVSRNDEIAEYENSSDEfraGSAFSGREYIYTNGSLLIQNITLSD 78

                         90       100
                 ....*....|....*....|....*
gi 254692835 113 TGYYTFQTIsKQGEMVSNTSLYLHV 137
Cdd:cd05741   79 TGFYTLEST-NIGGKTESATFQLHV 102

Immunoglobulin like; IG domains that cannot be classified into one of IGv1, IGc1, IGc2, IG.

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 254692835   392 TVRVQSSVVFTC-FSYNTGISIRWLFNNQN-LQLTERMTLSPSKCQ--LRIHTVRKEDAGEYQCEAFNPVSSKTSlPVRL 467
Cdd:smart00410   5 TVKEGESVTLSCeASGSPPPEVTWYKQGGKlLAESGRFSVSRSGSTstLTISNVTPEDSGTYTCAATNSSGSASS-GTTL 83

                   ..
gi 254692835   468 TV 469
Cdd:smart00410  84 TV 85

Immunoglobulin V-set domain; This domain is found in antibodies as well as neural protein P0 and CTL4 amongst others.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 254692835   42 PPQVVEGENVLLRV---DNMPENLLVFGWYRGMT--NLRHAIALYYSLTAKGLK---HSGRETL-YINGSLWIQNVTQED 112
Cdd:pfam07686   5 EVTVALGGSVTLPCtysSSMSEASTSVYWYRQPPgkGPTFLIAYYSNGSEEGVKkgrFSGRGDPsNGDGSLTIQNLTLSD 84

                          90       100
                  ....*....|....*....|....*.
gi 254692835  113 TGYYTFQTISKqGEMVSNTSLYLHVY 138
Cdd:pfam07686  85 SGTYTCAVIPS-GEGVFGKGTRLTVL 109

Immunoglobulin I-set domain;

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 254692835  390 DSTVRVQSSVVFTCfsYNTG---ISIRWLFNNQNLQLTER--MTLSPSKCQLRIHTVRKEDAGEYQCEAFNPVSSKTSlP 464
Cdd:pfam07679   9 DVEVQEGESARFTC--TVTGtpdPEVSWFKDGQPLRSSDRfkVTYEGGTYTLTISNVQPDDSGKYTCVATNSAGEAEA-S 85

                  ....*
gi 254692835  465 VRLTV 469
Cdd:pfam07679  86 AELTV 90

agrin-responsive second immunoglobulin-like domains (Ig2) of the Muscle-specific kinase (MuSK) ectodomain; a member of the I-set of Ig superfamily domains; The members here are composed of the second immunoglobulin-like (Ig) domains of the Muscle-specific kinase (MuSK) ectodomain. MuSK is a receptor tyrosine kinase specifically expressed in skeletal muscle, where it plays a central role in the formation and maintenance of the neuromuscular junction (NMJ). MuSK is activated by agrin, a neuron-derived heparan sulfate proteoglycan. The activation of MUSK in myotubes regulates the formation of NMJs through the regulation of different processes including the specific expression of genes in subsynaptic nuclei, the reorganization of the actin cytoskeleton and the clustering of the acetylcholine receptors (AChR) in the postsynaptic membrane. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the MuSK lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 254692835 381 VTQPAMRVTdstVRVQSSVVFTCFSY-NTGISIRWLFNNQNLQLTERMTLSPSKcQLRIHTVRKEDAGEYQCEAFNPVSS 459
Cdd:cd20968    2 ITRPPTNVT---IIEGLKAVLPCTTMgNPKPSVSWIKGDDLIKENNRIAVLESG-SLRIHNVQKEDAGQYRCVAKNSLGI 77

                         90
                 ....*....|
gi 254692835 460 KTSLPVRLTV 469
Cdd:cd20968   78 AYSKPVTIEV 87

Immunoglobulin domain; Members of the immunoglobulin superfamily are found in hundreds of proteins of different functions. Examples include antibodies, the giant muscle kinase titin and receptor tyrosine kinases. Immunoglobulin-like domains may be involved in protein-protein and protein-ligand interactions.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 254692835  392 TVRVQSSVVFTCFS--YNTGISIRWLFNNQnlQLTERMTLSPSKCQLRIHT-----VRKEDAGEYQCEAFNPVSSKTS 462
Cdd:pfam00047   7 TVLEGDSATLTCSAstGSPGPDVTWSKEGG--TLIESLKVKHDNGRTTQSSllisnVTKEDAGTYTCVVNNPGGSATL 82

Third immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the Constant 2 (C2)-set of IgSF domains; The members here are composed of the third immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. This group belongs to the C2-set of IgSF domains, having A, B, and E strands in one beta-sheet and A', G, F, C, and C' in the other. Unlike other Ig domain sets, the C2-set lacks the D strand.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 254692835 390 DSTVRVQSSVVFTCFSYNTGI-SIRWLFNNQNLQLTERMTLSpSKCQLRIHTVRKEDAGEYQCEAFNPVSS 459
Cdd:cd20957   10 VQTVDFGRTAVFNCSVTGNPIhTVLWMKDGKPLGHSSRVQIL-SEDVLVIPSVKREDKGMYQCFVRNDGDS 79

Immunoglobulin (Ig)-like domain of Down Syndrome Cell Adhesion molecule (DSCAM); The members here are composed of the immunoglobulin (Ig)-like domain of Down Syndrome Cell Adhesion molecule (DSCAM). DSCAM is a cell adhesion molecule expressed largely in the developing nervous system. The gene encoding DSCAM is located at human chromosome 21q22, the locus associated with the intellectual disability phenotype of Down Syndrome. DSCAM is predicted to be the largest member of the IG superfamily. It has been demonstrated that DSCAM can mediate cation-independent homophilic intercellular adhesion.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*.
gi 254692835  92 SGRETLYINGSLWIQNVTQEDTGYYTFQTISKQGEMVSNtSLYLHV 137
Cdd:cd05734   53 NGRIQLLSNGSLLIKHVLEEDSGYYLCKVSNDVGADISK-SMYLTV 97

Fifth Ig-like domain of Roundabout (Robo) homolog 1/2, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fifth Ig-like domain of Roundabout (Robo) homolog 1/2 and similar domains. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, -2, and -3), and three mammalian Slit homologs (Slit-1,-2, -3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, -2, and -3 are expressed by commissural neurons in the vertebrate spinal cord and Slits 1, -2, -3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of slit responsiveness, antagonizes slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be is the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. The fifth Ig-like domain of Robo 1 and 2 is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 254692835 390 DSTVRVQSSVVFTCFSYNTGI-SIRWLFN-NQNLQLTERMTLSPSKcQLRIHTVRKEDAGEYQCEAFNPvSSKTSLPVRL 467
Cdd:cd20952    8 NQTVAVGGTVVLNCQATGEPVpTISWLKDgVPLLGKDERITTLENG-SLQIKGAEKSDTGEYTCVALNL-SGEATWSAVL 85

                 ..
gi 254692835 468 TV 469
Cdd:cd20952   86 DV 87

Fourth immunoglobulin (Ig)-like domain of hemolin, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fourth immunoglobulin (Ig)-like domain of hemolin and similar proteins. Hemolin, an insect immunoglobulin superfamily (IgSF) member containing four Ig-like domains, is a lipopolysaccharide-binding immune protein induced during bacterial infection. Hemolin shares significant sequence similarity with the first four Ig-like domains of the transmembrane cell adhesion molecules (CAMs) of the L1 family. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The fourth Ig-like domain of hemolin is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

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                 ....*....|....*....|....*....|....*....|....*....|.
gi 254692835  91 HSGRE-------TLYINGSLWIQNVTQEDTGYYTFQTISKQGEMVSNTSLY 134
Cdd:cd20978   37 HNGKPlqgpmerATVEDGTLTIINVQPEDTGYYGCVATNEIGDIYTETLLH 87

Fourth Ig domain of the neural cell adhesion molecule contactin-2, and similar domains; The members here are composed of the fourth Ig domain of the neural cell adhesion molecule contactin-2. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. Contactin-2 (also called TAG-1, axonin-1) facilitates cell adhesion by homophilic binding between molecules in apposed membranes. The first four Ig domains form the intermolecular binding fragment which arranges as a compact U-shaped module by contacts between Ig domains 1 and 4, and domains 2 and 3. It has been proposed that a linear zipper-like array forms, from contactin-2 molecules alternatively provided by the two apposed membranes.

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                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 254692835 388 VTDSTVRVQSSVVFTC-FSYNTGISIRWLFNNQNLQLTERMTLSPSKcqLRIHTVRKEDAGEYQCEAFN 455
Cdd:cd05728    6 ISDTEADIGSSLRWECkASGNPRPAYRWLKNGQPLASENRIEVEAGD--LRITKLSLSDSGMYQCVAEN 72

Fourth immunoglobulin (Ig)-like domain of hemolin, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fourth immunoglobulin (Ig)-like domain of hemolin and similar proteins. Hemolin, an insect immunoglobulin superfamily (IgSF) member containing four Ig-like domains, is a lipopolysaccharide-binding immune protein induced during bacterial infection. Hemolin shares significant sequence similarity with the first four Ig-like domains of the transmembrane cell adhesion molecules (CAMs) of the L1 family. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The fourth Ig-like domain of hemolin is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 254692835 389 TDSTVRVQSSVVFTCFSynTGI---SIRWLFNNQNLQ-LTERMTLSpsKCQLRIHTVRKEDAGEYQCEAFNP---VSSKT 461
Cdd:cd20978    9 KNVVVKGGQDVTLPCQV--TGVpqpKITWLHNGKPLQgPMERATVE--DGTLTIINVQPEDTGYYGCVATNEigdIYTET 84

                 ....
gi 254692835 462 SLPV 465
Cdd:cd20978   85 LLHV 88

Fifth immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fifth immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. This group is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

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                 ....*....|....*....|....*....|....*....|....*..
gi 254692835 411 SIRWLFNNQNLQLTERMTLSPSKcQLRIHTV-RKEDAGEYQCEAFNP 456
Cdd:cd20958   31 SITWEKDGRRLPLNHRQRVFPNG-TLVIENVqRSSDEGEYTCTARNQ 76

Immunoglobulin like; IG domains that cannot be classified into one of IGv1, IGc1, IGc2, IG.

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                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 254692835    45 VVEGENVLL--RVDNMPENllVFGWYRGmtnlrHAIALYYSLTAKGLKHSGretlyiNGSLWIQNVTQEDTGYYTFQTIS 122
Cdd:smart00410   6 VKEGESVTLscEASGSPPP--EVTWYKQ-----GGKLLAESGRFSVSRSGS------TSTLTISNVTPEDSGTYTCAATN 72

                           90
                   ....*....|..
gi 254692835   123 KQGEMVSNTSLY 134
Cdd:smart00410  73 SSGSASSGTTLT 84