lipocalin/cytosolic fatty acid-binding protein family; Lipocalins are diverse, mainly low molecular weight extracellular proteins that bind principally small hydrophobic ligands, and form covalent or non-covalent complexes with soluble macromolecules as well as membrane bound-receptors. They have a large beta-barrel ligand-binding cavity. Members include retinol-binding protein, retinoic acid-binding protein, complement protein C8 gamma, Can f 2, apolipoprotein D, extracellular fatty acid-binding protein, beta-lactoglobulin, oderant-binding protein, and bacterial lipocalin Blc. Lipocalins are involved in many important processes such as ligand transport, modulation of cell growth and metabolism, regulation of immune response, smell reception, tissue development and animal behavior. Cytosolic fatty acid-binding proteins also bind hydrophobic ligands in a non-covalent, reversible manner, and are involved in protection and shuttling of fatty acids within the cell, and in acquisition and removal of fatty acids from intracellular sites.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568931708  65 IDFATRKIAKLLKPQKVIEQNGDSFTIQTCSSLRNYLVKFKVGEEFEEDNKGLDNRKCTSLVTWENDKLTCVQRGEKKNR 144
Cdd:cd19465   23 IDFATRKIAKLLKPQKVIEQNGDSFTIHTNSSLRNYFVKFKVGEEFDEDNRGLDNRKCKSLVIWDNDRLTCIQKGEKKNR 102

                         90       100
                 ....*....|....*....|....*....
gi 568931708 145 GWSHWIEGDQLHLEMFCEGQVCKQTFQRA 173
Cdd:cd19465  103 GWTHWIEGDKLHLEMFCEGQVCKQTFQRA 131

cellular retinol-binding protein 4; Cellular retinol-binding proteins (CRBPs) participate in the cellular uptake of vitamin A in the form of free retinol. Retinol achieves a higher chemical stability when bound to CRBPs, and its interaction with retinol-binding proteins allows the solubilization in the aqueous medium of the hydrophobic retinol molecule. There are four human CRBP types (CRBP1, -2, -3, -4) which differ in their tissue-specific expression pattern, as well as in their different ligand affinities. This group includes human CRBP4 (also known as retinoid-binding protein 7, CRABP4, CRBP4, CRBPIV) which is expressed primarily in kidney, heart, and transverse colon, and mouse CRBP4 which is highly expressed in white adipose tissue and mammary gland. Human CRBP4 binds retinol with an affinity lower than those for CRBP1, -2, -3. CRBPs belong to the intracellular fatty acid-binding protein (FABP) family, members of which are small proteins that bind hydrophobic ligands in a non-covalent, reversible manner, and, besides CRBPS, include the cellular retinoic acid-binding proteins (CRABPs) and the fatty acid-binding proteins (FABPs).

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568931708  65 IDFATRKIAKLLKPQKVIEQNGDSFTIQTCSSLRNYLVKFKVGEEFEEDNKGLDNRKCTSLVTWENDKLTCVQRGEKKNR 144
Cdd:cd19465   23 IDFATRKIAKLLKPQKVIEQNGDSFTIHTNSSLRNYFVKFKVGEEFDEDNRGLDNRKCKSLVIWDNDRLTCIQKGEKKNR 102

                         90       100
                 ....*....|....*....|....*....
gi 568931708 145 GWSHWIEGDQLHLEMFCEGQVCKQTFQRA 173
Cdd:cd19465  103 GWTHWIEGDKLHLEMFCEGQVCKQTFQRA 131

cellular retinol-binding protein 4; Cellular retinol-binding proteins (CRBPs) participate in the cellular uptake of vitamin A in the form of free retinol. Retinol achieves a higher chemical stability when bound to CRBPs, and its interaction with retinol-binding proteins allows the solubilization in the aqueous medium of the hydrophobic retinol molecule. There are four human CRBP types (CRBP1, -2, -3, -4) which differ in their tissue-specific expression pattern, as well as in their different ligand affinities. This group includes human CRBP4 (also known as retinoid-binding protein 7, CRABP4, CRBP4, CRBPIV) which is expressed primarily in kidney, heart, and transverse colon, and mouse CRBP4 which is highly expressed in white adipose tissue and mammary gland. Human CRBP4 binds retinol with an affinity lower than those for CRBP1, -2, -3. CRBPs belong to the intracellular fatty acid-binding protein (FABP) family, members of which are small proteins that bind hydrophobic ligands in a non-covalent, reversible manner, and, besides CRBPS, include the cellular retinoic acid-binding proteins (CRABPs) and the fatty acid-binding proteins (FABPs).

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568931708  65 IDFATRKIAKLLKPQKVIEQNGDSFTIQTCSSLRNYLVKFKVGEEFEEDNKGLDNRKCTSLVTWENDKLTCVQRGEKKNR 144
Cdd:cd19465   23 IDFATRKIAKLLKPQKVIEQNGDSFTIHTNSSLRNYFVKFKVGEEFDEDNRGLDNRKCKSLVIWDNDRLTCIQKGEKKNR 102

                         90       100
                 ....*....|....*....|....*....
gi 568931708 145 GWSHWIEGDQLHLEMFCEGQVCKQTFQRA 173
Cdd:cd19465  103 GWTHWIEGDKLHLEMFCEGQVCKQTFQRA 131

cellular retinol-binding protein 1; Cellular retinol-binding proteins (CRBPs) participate in the cellular uptake of vitamin A in the form of free retinol. Retinol achieves a higher chemical stability when bound to CRBPs, and its interaction with retinol-binding proteins allows the solubilization in the aqueous medium of the hydrophobic retinol molecule. There are four human CRBP types (CRBP1, -2, -3, -4) which differ in their tissue-specific expression pattern, as well as in their different ligand affinities. CRBP1 (also known as Retinol-Binding Protein 1, CRBP, RBPC, CRBP1, CRBPI, CRABP-I) is widely expressed in numerous tissues: it has highest abundance in the liver, kidney, lung, and retinal pigment epithelium cells of the eye. CRBP1 has a high affinity for retinol. It accepts retinol transported from the plasma to cytosol via a cell surface receptor named STRA6, which interacts with serum retinol-binding protein. CRBP1 can bind all-trans-retinol, all trans-retinal and 13-cis-retinol, but not 9-cis-retinol. CRBPs belong to the intracellular fatty acid-binding protein (FABP) family, members of which are small proteins that bind hydrophobic ligands in a non-covalent, reversible manner, and, besides CRBPS, include the cellular retinoic acid-binding proteins (CRABPs) and the fatty acid-binding proteins (FABPs).

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568931708  65 IDFATRKIAKLLKPQKVIEQNGDSFTIQTCSSLRNYLVKFKVGEEFEEDNKGLDNRKCTSLVTWENDKLTCVQRGEKKNR 144
Cdd:cd19462   23 VNVALRKIANLLKPDKEIVQDGDHMIIRTLSTFRNYIMDFQVGKEFEEDLTGIDDRKCMTTVSWDGDKLQCVQKGEKEGR 102

                         90       100
                 ....*....|....*....|....*...
gi 568931708 145 GWSHWIEGDQLHLEMFCEGQVCKQTFQR 172
Cdd:cd19462  103 GWTQWIEGDELHLEMRVEGVVCKQVFKK 130

cellular retinol-binding protein 3; Cellular retinol-binding proteins (CRBPs) participate in the cellular uptake of vitamin A in the form of free retinol. Retinol achieves a higher chemical stability when bound to CRBPs, and its interaction with retinol-binding proteins allows the solubilization in the aqueous medium of the hydrophobic retinol molecule. There are four human CRBP types (CRBP1, -2, -3, -4) which differ in their tissue-specific expression pattern, as well as in their different ligand affinities. This group includes human CRBP3 (also known as retinol-binding protein 5, HRBPiso) which is expressed at highest levels in kidney and liver. CRBP3 binds retinol, and may be a human intracellular carrier of retinol in such tissues. CRBPs belong to the intracellular fatty acid-binding protein (FABP) family, members of which are small proteins that bind hydrophobic ligands in a non-covalent, reversible manner, and, besides CRBPS, include the cellular retinoic acid-binding proteins (CRABPs) and the fatty acid-binding proteins (FABPs).

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568931708  64 SIDFATRKIAKLLKPQKVIEQNGDSFTIQTCSSLRNYLVKFKVGEEFEEDNKGLDNRKCTSLVTWENDKLTCVQRGEKKN 143
Cdd:cd19464   22 NVNMALRKIVLLLKPDKEIEHQGNHMTVRTLSTFRNYVMDFDLGVEFEEDLRSVDGRKCQTTVTWEEEKLVCVQKGEVPN 101

                         90       100
                 ....*....|....*....|....*....
gi 568931708 144 RGWSHWIEGDQLHLEMFCEGQVCKQTFQR 172
Cdd:cd19464  102 RGWRHWLEGEMLHLELTARDAVCKQVFRK 130

fatty acid-binding protein 3 and similar proteins including FABP4, -5, -7, -8, -9, -11, and -12; This FABP3-like subfamily includes FABP3, -4, -5, -7, -8, -9, -11, -12, and similar proteins and belongs to the intracellular fatty acid-binding protein (FABP) family, members of which are small proteins that bind hydrophobic ligands in a non-covalent, reversible manner, and have been implicated in intracellular uptake, transport and storage of hydrophobic ligands, regulation of lipid metabolism and sequestration of excess toxic fatty acids, as well as in signaling, gene expression, inflammation, cell growth and proliferation, and cancer development.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568931708  67 FATRKIAKLLKPQKVIEQNGDSFTIQTCSSLRNYLVKFKVGEEFEEDNKglDNRKCTSLVTWENDKLTCVQRGEKKNRGW 146
Cdd:cd19443   25 FATRKLGNLAKPTVIISVDGDKITIKTESTFKNTEISFKLGEEFDETTA--DGRKTKSTVTLDNGKLVQVQKWDGKETTI 102

                         90       100
                 ....*....|....*....|....*.
gi 568931708 147 SHWIEGDQLHLEMFCEGQVCKQTFQR 172
Cdd:cd19443  103 VRELKDGKLVVTCTMGDVVCTRTYEK 128

fatty acid binding protein 3; FABP3 (also known as heart-type fatty acid binding protein, H-FABP, MDGI, O-FABP) is a cytosolic protein mainly expressed in cardiac and skeletal muscle cells. In these tissues, it plays an important role in fatty acid transportation, cell growth, cell signaling, and gene transcription. This subgroup belongs to the intracellular fatty-acid binding protein (FABP) family, members of which are small proteins that bind hydrophobic ligands in a non-covalent, reversible manner, and have been implicated in intracellular uptake, transport and storage of hydrophobic ligands, regulation of lipid metabolism and sequestration of excess toxic fatty acids, as well as in signaling, gene expression, inflammation, cell growth and proliferation, and cancer development.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568931708  65 IDFATRKIAKLLKPQKVIEQNGDSFTIQTCSSLRNYLVKFKVGEEFEEDNKglDNRKCTSLVTWENDKLTCVQRGEKKNR 144
Cdd:cd19466   23 VGFATRQVGNMTKPTTIIEVDGDKVTLKTQSTFKNTEISFKLGEEFDETTA--DDRKVKSLVTLDGGKLVHVQKWDGKET 100

                         90       100
                 ....*....|....*....|....*...
gi 568931708 145 GWSHWIEGDQLHLEMFCEGQVCKQTFQR 172
Cdd:cd19466  101 TLVREVSDGKLILTLTLGDVVSTRTYEK 128

fatty acid binding protein 4; FABP4 (also known as A-FABP, adipocyte fatty acid binding protein, aP2) is highly expressed in macrophages and in adipocytes where it regulates fatty acid storage and lipolysis and is an important mediator of inflammation. It binds long chain fatty acids, retinoic acid and eicosanoids. This subgroup belongs to the intracellular fatty-acid binding protein (FABP) family, members of which are small proteins that bind hydrophobic ligands in a non-covalent, reversible manner, and have been implicated in intracellular uptake, transport and storage of hydrophobic ligands, regulation of lipid metabolism and sequestration of excess toxic fatty acids, as well as in signaling, gene expression, inflammation, cell growth and proliferation, and cancer development.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568931708  65 IDFATRKIAKLLKPQKVIEQNGDSFTIQTCSSLRNYLVKFKVGEEFEEDNkgLDNRKCTSLVTWENDKLTCVQRGEKKNR 144
Cdd:cd19467   25 VGFATRKVAGMAKPNMIISVNGDVITIRSESTFKNTEISFKLGVEFDEVT--ADDRKVKSIITLDGGALVQVQKWDGKST 102

                         90       100
                 ....*....|....*....|....*...
gi 568931708 145 GWSHWIEGDQLHLEMFCEGQVCKQTFQR 172
Cdd:cd19467  103 TIKRKRDDDKLVVECVMKGVTSTRVYER 130

fatty acid-binding protein ReP1-NCXSQ and similar proteins; Arthropod ReP1-NCXSQ (regulatory protein of the squid nerve sodium calcium exchanger) is required for MgATP stimulation of the squid nerve Na(+)/Ca(2+) exchanger NCXSQ1. ReP1-NCXSQ acts as a carrier of fatty acids; is possible that its biological ligand is palmitic acid, which is abundant in squid axons. The mechanism for fine-tuning of the regulation of NCXSQ1 by ReP1-NCXSQ may then involve the transport of palmitic acid. This subgroup belongs to the intracellular fatty acid-binding protein (FABP) family, members of which are small proteins that bind hydrophobic ligands in a non-covalent, reversible manner, and have been implicated in intracellular uptake, transport and storage of hydrophobic ligands, regulation of lipid metabolism and sequestration of excess toxic fatty acids, as well as in signaling, gene expression, inflammation, cell growth and proliferation, and cancer development.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568931708  70 RKIAKLLKPQKVIEQNGDSFTIQTCSSLRNYLVKFKVGEEFEEDNkgLDNRKCTSLVTWENDKLTCVQRGEK-KNRGWSH 148
Cdd:cd19449   28 RKMGNAATPTVEIKIDGDSWSLKTSTTFKTTEIKFKLGQEFDETT--GDGRKIKTTCTIDGNKLIQDQKGSKgKDSILTR 105

                         90       100
                 ....*....|....*....|....
gi 568931708 149 WIEGDQLHLEMFCEGQVCKQTFQR 172
Cdd:cd19449  106 EFKDGQMHMILKVDDVVCTRIYKR 129

Cellular retinoic acid-binding protein 2; Cellular retinoic acid-binding proteins (CRABPs) play a role in the metabolism of vitamin A and retinoic acid. They bind all trans retinoic acid, but not retinol. Retinol, the alcohol form of vitamin A, is an essential dietary nutrient. Within the cell, it gets oxidized into its biologically active acid form, retinoic acid, which interacts with the nuclear receptors (RARs and RXRs). The two CRABPs (CRABP1 AND CRABP2) differ in their pattern of expression across cells and developmental stages. Like other lipid binding proteins, CRABPs serve to solubilize and protect their ligand in the aqueous cytosol and transport retinoic acid between cellular compartments. This subgroup includes CRABP2 (also known as CRABP-II, RBP6) which transports retinoic acid to the nucleus, and delivers all-trans-retinoic acid to nuclear retinoic acid receptors. CRABPs belong to the intracellular fatty acid-binding protein (FABP) family, members of which are small proteins that bind hydrophobic ligands in a non-covalent, reversible manner, and besides CRABPS include the cellular retinol-binding protein (CRBPs) and the fatty acid-binding proteins (FABPs).

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568931708  65 IDFATRKIA--KLLKPQKVIEQNGDSFTIQTCSSLRNYLVKFKVGEEFEEdnKGLDNRKCTSLVTWEND-KLTCVQ---R 138
Cdd:cd19461   23 VNVMLRKIAvaAASKPAVEIKQEGDTFYIKTSTTVRTTEINFKVGEEFEE--QTVDGRPCKSLVKWESEnKMVCEQkllK 100

                         90       100       110
                 ....*....|....*....|....*....|....*
gi 568931708 139 GEKKNRGWSHWIEGD-QLHLEMFCEGQVCKQTFQR 172
Cdd:cd19461  101 GEGPKTSWTRELTNDgELILTMTADDVVCTRVYVR 135

fatty acid binding protein 8; FABP8 (also known as peripheral myelin protein 2, PMP2, myelin fatty acid binding protein, M-FABP, myelin P2 protein, MP2) is a fatty acid-binding structural component of the myelin sheath in the peripheral nervous system and may play a role in lipid transport and homeostasis in myelin. It may bind cholesterol which is present in myelin at high concentrations. In addition to binding momomeric ligands, P2 is able to bind membrane surfaces, and to stack lipid bilayers together. This subgroup belongs to the intracellular fatty-acid binding protein (FABP) family, members of which are small proteins that bind hydrophobic ligands in a non-covalent, reversible manner, and have been implicated in intracellular uptake, transport and storage of hydrophobic ligands, regulation of lipid metabolism and sequestration of excess toxic fatty acids, as well as in signaling, gene expression, inflammation, cell growth and proliferation, and cancer development.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568931708  65 IDFATRKIAKLLKPQKVIEQNGDSFTIQTCSSLRNYLVKFKVGEEFEEDNKglDNRKCTSLVTWENDKLTCVQRGEKKNR 144
Cdd:cd19469   24 VGLATRKLGNLAKPTVIISKKGDIITIRTESTFKNTEISFKLGQEFEETTA--DNRKTKSTVTLARGSLNQVQKWNGKET 101

                         90       100
                 ....*....|....*....|....*...
gi 568931708 145 GWSHWIEGDQLHLEMFCEGQVCKQTFQR 172
Cdd:cd19469  102 TIKRKLVDGKMVVECKMKGVVCTRIYEK 129

fatty acid-binding protein similar to Locusta migratoria FABP (Lm-FABP); This subfamily includes fatty acid-binding protein found mainly in insects such as the migratory locust (Locusta migratoria) FABP (Lm-FABP) and the desert locust (Schistocerca gregaria) FABP (Sg-FABP), having flight muscle tissues that contain unusually high levels FABP, similar to migratory birds. Both Sg- and Lm-FABP are closely related to the mammalian i-LBP subfamily IV, especially to the heart and adipocyte FABP forms. This subgroup belongs to the intracellular fatty-acid binding protein (FABP) family, members of which are small proteins that bind hydrophobic ligands in a non-covalent, reversible manner, and have been implicated in intracellular uptake, transport and storage of hydrophobic ligands, regulation of lipid metabolism and sequestration of excess toxic fatty acids, as well as in signaling, gene expression, inflammation, cell growth and proliferation, and cancer development.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 568931708  65 IDFATRKIAKLLKPQKVIEQNGDSFTIQTCSSLRNYLVKFKVGEEFEEDNkgLDNRKCTSLVTWENDKLTCVQRGEK 141
Cdd:cd19852   24 VGLITRKAGNALTPVVELELEDGTYTLTTSTTFKTTEFKFKLGEEFDEET--LDGRKVKSIITFDGNKLVQEQKGDH 98

fatty acid binding protein 5; FABP5 (also known as epidermal FABP, E-FABP, cutaneous fatty-acid-binding protein, C-FABP, psoriasis-associated fatty-acid-binding protein, KFABP, PA-FABP) binds a wide array of ligands. It is an intracellular carrier for long-chain fatty acids and related active lipids, and also selectively delivers specific fatty acids from the cytosol to the nucleus. Its ligands include vitamin A metabolite all-trans-retinoic acid, endocannabinoid and numerous synthetic drugs and probes. It may be involved in keratinocyte differentiation. Mouse FABP5 is found only in the monomeric form; however, human FABP5 can exist as a monomer as well as a domain-swapped dimer. This subgroup belongs to the intracellular fatty-acid binding protein (FABP) family, members of which are small proteins that bind hydrophobic ligands in a non-covalent, reversible manner, and have been implicated in intracellular uptake, transport and storage of hydrophobic ligands, regulation of lipid metabolism and sequestration of excess toxic fatty acids, as well as in signaling, gene expression, inflammation, cell growth and proliferation, and cancer development.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568931708  65 IDFATRKIAKLLKPQKVIEQNGDSFTIQTCSSLRNYLVKFKVGEEFEEDNkgLDNRKCTSLVTWENDKLTCVQRGEKKNR 144
Cdd:cd19468   23 VGLALRKMGAMAKPDCIITCDGNNITVKTESTVKTTQFSCNLGEKFEETT--ADGRKTQTVCTFQDGALVQHQEWDGKES 100

                         90       100
                 ....*....|....*....|....*...
gi 568931708 145 GWSHWIEGDQLHLEMFCEGQVCKQTFQR 172
Cdd:cd19468  101 TITRKLKDGKLVVECVMNNATCTRVYEK 128

liver bile acid-binding protein and similar proteins; Liver bile acid-binding protein (also known as "fatty acid-binding protein, liver", LB-FABP, L-BABP, L-FABP, FABP1) is present in the liver of the vertebrates fish, amphibians, reptiles, and birds but not in mammals. L-BABPs bind free fatty acids and their coenzyme A derivatives, bilirubin, and some other small molecules in the cytoplasm. The role of L-BABPs may be that of cellular and metabolic trafficking of bile acids; they may be involved in intracellular lipid transport. This subgroup belongs to the intracellular fatty acid-binding protein (FABP) family, members of which are small proteins that bind hydrophobic ligands in a non-covalent, reversible manner, and have been implicated in intracellular uptake, transport and storage of hydrophobic ligands, regulation of lipid metabolism and sequestration of excess toxic fatty acids, as well as in signaling, gene expression, inflammation, cell growth and proliferation, and cancer development.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 568931708  71 KIAKLLKPQKVIEQNGDSFTIQTCSSLRNYLVKFKVGEEFEEDNkgLDNRKCTSLVTWENDKLTC 135
Cdd:cd19447   29 KMAKDVKPVTEIQQNGDEFVVTSKTPRQTVTNSFTIGKEAEITT--MDGKKIKCTVHLEGGKLVC 91