Second immunoglobulin (Ig)-like domain of Fcgamma-receptors (FcgammaRs), and similar domains; The members here are composed of the second immunoglobulin (Ig)-like domain of Fcgamma-receptors (FcgammaRs). Interactions between IgG and FcgammaR are important to the initiation of cellular and humoral response. IgG binding to FcgammaR leads to a cascade of signals and ultimately to functions such as antibody-dependent-cellular-cytotoxicity (ADCC), endocytosis, phagocytosis, release of inflammatory mediators, etc. FcgammaR has two Ig-like domains. This group also contains FcepsilonRI which binds IgE with high affinity.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1820045865 108 WLLLQAPRWVFKEEDPIHLRCHSWKNTALHKVTYLQNGKGRKYFHHNSDFYIPKATLKDSGSYFCRGLFGSKNVSSETVN 187
Cdd:cd05753     1 WLLLQAPSAVVFEGEPLTLRCHGWKDKKVHKVTYYKDGKALKFSYENSNFSIPQATLSDSGSYHCSGTVRIKRRSSESVN 80

                  ...
gi 1820045865 188 ITI 190
Cdd:cd05753    81 ITV 83

Second immunoglobulin (Ig)-like domain of Fcgamma-receptors (FcgammaRs), and similar domains; The members here are composed of the second immunoglobulin (Ig)-like domain of Fcgamma-receptors (FcgammaRs). Interactions between IgG and FcgammaR are important to the initiation of cellular and humoral response. IgG binding to FcgammaR leads to a cascade of signals and ultimately to functions such as antibody-dependent-cellular-cytotoxicity (ADCC), endocytosis, phagocytosis, release of inflammatory mediators, etc. FcgammaR has two Ig-like domains. This group also contains FcepsilonRI which binds IgE with high affinity.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1820045865 108 WLLLQAPRWVFKEEDPIHLRCHSWKNTALHKVTYLQNGKGRKYFHHNSDFYIPKATLKDSGSYFCRGLFGSKNVSSETVN 187
Cdd:cd05753     1 WLLLQAPSAVVFEGEPLTLRCHGWKDKKVHKVTYYKDGKALKFSYENSNFSIPQATLSDSGSYHCSGTVRIKRRSSESVN 80

                  ...
gi 1820045865 188 ITI 190
Cdd:cd05753    81 ITV 83

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

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1820045865   32 PQWYRVLEKDSVTLKCQGAYSPEDNSTqWFHN--ESLI---------SSQASSYFIDAATVDDSGEYRCQTNLS--TLSD 98
Cdd:smart00410   1 PPSVTVKEGESVTLSCEASGSPPPEVT-WYKQggKLLAesgrfsvsrSGSTSTLTISNVTPEDSGTYTCAATNSsgSASS 79

                   ....*.
gi 1820045865   99 PVQLEV 104
Cdd:smart00410  80 GTTLTV 85

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

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1820045865  114 PRWVFKEEDPIHLRCH---------SWKNTALHKVTYLQNGKGRKYfHHNSDFYIPKATLKDSGSYFCRGLFGSKNVSSE 184
Cdd:smart00410   2 PSVTVKEGESVTLSCEasgspppevTWYKQGGKLLAESGRFSVSRS-GSTSTLTISNVTPEDSGTYTCAATNSSGSASSG 80

                   .
gi 1820045865  185 T 185
Cdd:smart00410  81 T 81

Second immunoglobulin (Ig)-like domain of Fcgamma-receptors (FcgammaRs), and similar domains; The members here are composed of the second immunoglobulin (Ig)-like domain of Fcgamma-receptors (FcgammaRs). Interactions between IgG and FcgammaR are important to the initiation of cellular and humoral response. IgG binding to FcgammaR leads to a cascade of signals and ultimately to functions such as antibody-dependent-cellular-cytotoxicity (ADCC), endocytosis, phagocytosis, release of inflammatory mediators, etc. FcgammaR has two Ig-like domains. This group also contains FcepsilonRI which binds IgE with high affinity.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1820045865 108 WLLLQAPRWVFKEEDPIHLRCHSWKNTALHKVTYLQNGKGRKYFHHNSDFYIPKATLKDSGSYFCRGLFGSKNVSSETVN 187
Cdd:cd05753     1 WLLLQAPSAVVFEGEPLTLRCHGWKDKKVHKVTYYKDGKALKFSYENSNFSIPQATLSDSGSYHCSGTVRIKRRSSESVN 80

                  ...
gi 1820045865 188 ITI 190
Cdd:cd05753    81 ITV 83

Immunoglobulin domain; This family contains immunoglobulin-like domains.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 1820045865  27 VVFLEPQWYRVLEKDSVTLKCQGAYSPEdNSTQWFHNESLISSQASSYF----------IDAATVDDSGEYRCQ 90
Cdd:pfam13927   3 VITVSPSSVTVREGETVTLTCEATGSPP-PTITWYKNGEPISSGSTRSRslsgsnstltISNVTRSDAGTYTCV 75

Immunoglobulin (Ig)-like domain of human carcinoembryonic antigen (CEA) related cell adhesion molecule (CEACAM) domains 2, 4, and 6, and similar domains; The members here are composed of the second, fourth, and sixth immunoglobulin (Ig)-like domains in human carcinoembryonic antigen (CEA) related cell adhesion molecule (CEACAM) protein subfamily. 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 1820045865  37 VLEKDSVTLKCqgaySPEDNSTQ---WFHNESL-------ISSQASSYFIDAATVDDSGEYRCQT-NL--STLSDPVQLE 103
Cdd:cd05740    12 VEDKDAVTLTC----EPETQNTSylwWFNGQSLpvtprltLSNGNRTLTLLNVTREDAGAYQCEIsNPvsANRSDPVTLD 87

                  .
gi 1820045865 104 V 104
Cdd:cd05740    88 V 88

Immunoglobulin (Ig)-like domain found in Leukocyte Ig-like receptors, Natural killer inhibitory receptors (KIRs) and similar domains; member of Immunoglobulin Constant-2 set of IgSF domains; The members here are composed of the first and second immunoglobulin (Ig)-like domains found in Leukocyte Ig-like receptors (LILRs), Natural killer inhibitory receptors (KIRs, also known as also known as cluster of differentiation (CD) 158), and similar proteins. This group includes LILRB1 (also known as LIR-1), LILRA5 (also known as LIR9), an activating natural cytotoxicity receptor NKp46, the immune-type receptor glycoprotein VI (GPVI), and the IgA-specific receptor Fc-alphaRI (also known as cluster of differentiation (CD) 89). LILRs are a family of immunoreceptors expressed on expressed on T and B cells, on monocytes, dendritic cells, and subgroups of natural killer (NK) cells. The human LILR family contains nine proteins (LILRA1-3, and 5, and LILRB1-5). From functional assays, and as the cytoplasmic domains of various LILRs, for example LILRB1, LILRB2 (also known as LIR-2), and LILRB3 (also known as LIR-3) contain immunoreceptor tyrosine-based inhibitory motifs (ITIMs), it is thought that LIR proteins are inhibitory receptors. Of the eight LIR family proteins, only LILRB1, and LILRB2, show detectable binding to class I MHC molecules; ligands for the other members have yet to be determined. The extracellular portions of the different LIR proteins contain different numbers of Ig-like domains for example, four in the case of LILRB1, and LILRB2, and two in the case of LILRB4 (also known as LIR-5). The activating natural cytotoxicity receptor NKp46 is expressed in natural killer cells, and is organized as an extracellular portion having two Ig-like extracellular domains, a transmembrane domain, and a small cytoplasmic portion. GPVI, which also contains two Ig-like domains, participates in the processes of collagen-mediated platelet activation and arterial thrombus formation. Fc-alphaRI is expressed on monocytes, eosinophils, neutrophils, and macrophages; it mediates IgA-induced immune effector responses such as phagocytosis, antibody-dependent cell-mediated cytotoxicity and respiratory burst. Killer cell immunoglobulin-like receptors (KIRs; also known as CD158 for human KIR) are transmembrane glycoproteins expressed by natural killer cells and subsets of T cells. KIRs are a family of highly polymorphic activating and inhibitory receptors that serve as key regulators of human NK cell function. The KIR proteins are classified by the number of extracellular immunoglobulin domains (2D or 3D) and by whether they have a long (L) or short (S) cytoplasmic domain. KIR proteins with the long cytoplasmic domain transduce inhibitory signals upon ligand binding via an immune tyrosine-based inhibitory motif (ITIM), while KIR proteins with the short cytoplasmic domain lack the ITIM motif and instead associate with the TYRO protein tyrosine kinase binding protein to transduce activating signals. The major ligands for KIR are MHC class I (HLA-A, -B or -C) molecules.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1820045865  37 VLEKDSVTLKCQGAysPEDNSTQWFHNESLISSQ---------ASSYFIDAATVDDSGEYRCQTNLSTL----SDPVQLE 103
Cdd:cd16843    12 VPLGENVTIRCQGP--PEAVLFQLYKEGNSLSQGtvrekepqnKAEFYIPHMDRNHAGRYRCRYRSGTLwsepSDPLELV 89

                  .
gi 1820045865 104 V 104
Cdd:cd16843    90 V 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 1820045865  114 PRWVFKEEDPIHLRCH---------SWKNTALHKVTYLQNGKGRKYfHHNSDFYIPKATLKDSGSYFCRGLFGSKNVSSE 184
Cdd:smart00410   2 PSVTVKEGESVTLSCEasgspppevTWYKQGGKLLAESGRFSVSRS-GSTSTLTISNVTPEDSGTYTCAATNSSGSASSG 80

                   .
gi 1820045865  185 T 185
Cdd:smart00410  81 T 81

Immunoglobulin (Ig)-like domain of platelet-derived growth factor (PDGF) receptors (R), alpha and beta; member of the I-set of IgSF domains; The members here are composed of the immunoglobulin (Ig)-like domain of platelet-derived growth factor (PDGF) receptors (R), alpha (also known as cluster of differentiation (CD) 140a), and beta (also known as CD140b). PDGF is a potent mitogen for connective tissue cells. PDGF-stimulated processes are mediated by three different PDGFs (PDGF-A,PDGF-B, and PDGF-C). PDGFRalpha binds to all three PDGFs, whereas the PDGFRbeta binds only to PDGF-B. PDGFRs alpha and beta have similar organization: an extracellular component with five Ig-like domains, a transmembrane segment, and a cytoplasmic portion having protein tyrosine kinase activity. In mice, PDGFRalpha and PDGFRbeta are essential for normal development.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1820045865 111 LQAPRWVFKEEDPIHLRCHSWKNTALH-KVTYLQNGKGR----------KYFHHNSDFYIPKATLKDSGSYFCRGLFGSK 179
Cdd:cd05861     7 MEAVKTVVRQGETITLMCIVIGNEVVDlEWTYPGKESGRgiepveefkvPPYHLVYTLTIPSATLEDSGTYECAVTEATN 86

                          90
                  ....*....|..
gi 1820045865 180 NVSSE-TVNITI 190
Cdd:cd05861    87 DHQDEkKINITV 98

First immunoglobulin (Ig)-like domain found in Leukocyte Ig-like receptors (LILRs), Natural killer inhibitory receptors (KIRs) and similar domains; member of Immunoglobulin Constant-2 set of IgSF domains; The members here are composed of the first immunoglobulin (Ig)-like domain found in Leukocyte Ig-like receptors (LILRs) and Natural killer inhibitory receptors (KIRs, also known as also known as cluster of differentiation (CD) 158), and similar proteins. This group includes LILRB1 (also known as LIR-1), LILRA5 (also known as LIR9), an activating natural cytotoxicity receptor NKp46, the immune-type receptor glycoprotein VI (GPVI), and the IgA-specific receptor Fc-alphaRI (also known as cluster of differentiation (CD) 89). LILRs are a family of immunoreceptors expressed on expressed on T and B cells, on monocytes, dendritic cells, and subgroups of natural killer (NK) cells. The human LILR family contains nine proteins (LILRA1-3, and 5, and LILRB1-5). From functional assays, and as the cytoplasmic domains of various LILRs, for example LILRB1, LILRB2 (also known as LIR-2), and LILRB3 (also known as LIR-3) contain immunoreceptor tyrosine-based inhibitory motifs (ITIMs), it is thought that LIR proteins are inhibitory receptors. Of the eight LIR family proteins, only LILRB1, and LILRB2, show detectable binding to class I MHC molecules; ligands for the other members have yet to be determined. The extracellular portions of the different LIR proteins contain different numbers of Ig-like domains for example, four in the case of LILRB1, and LILRB2, and two in the case of LILRB4 (also known as LIR-5). The activating natural cytotoxicity receptor NKp46 is expressed in natural killer cells, and is organized as an extracellular portion having two Ig-like extracellular domains, a transmembrane domain, and a small cytoplasmic portion. GPVI, which also contains two Ig-like domains, participates in the processes of collagen-mediated platelet activation and arterial thrombus formation. Fc-alphaRI is expressed on monocytes, eosinophils, neutrophils, and macrophages; it mediates IgA-induced immune effector responses such as phagocytosis, antibody-dependent cell-mediated cytotoxicity and respiratory burst. Killer cell immunoglobulin-like receptors (KIRs; also known as CD158 for human KIR) are transmembrane glycoproteins expressed by natural killer cells and subsets of T cells. KIRs are a family of highly polymorphic activating and inhibitory receptors that serve as key regulators of human NK cell function. The KIR proteins are classified by the number of extracellular immunoglobulin domains (2D or 3D) and by whether they have a long (L) or short (S) cytoplasmic domain. KIR proteins with the long cytoplasmic domain transduce inhibitory signals upon ligand binding via an immune tyrosine-based inhibitory motif (ITIM), while KIR proteins with the short cytoplasmic domain lack the ITIM motif and instead associate with the TYRO protein tyrosine kinase binding protein to transduce activating signals. The major ligands for KIR are MHC class I (HLA-A, -B or -C) molecules.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 1820045865  42 SVTLKCQGAY-------SPEDNSTQWFHNESLISSqaSSYFIDAATVDDSGEYRCQTNLSTL----SDPVQLEV 104
Cdd:cd05751    17 SVTIRCQGTPeaflyqlEKEGNSTETVIPKKPQKK--AEFIIPHMNSRTAGRYRCRYRKGAGwsepSDLLELVV 88

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 1820045865 117 VFKEEDPIHLRCHSWKNTALHKVTYLQNGK----GRKYFHHN-----SDFYIPKATLKDSGSYFCRGLFGSKNVSSET 185
Cdd:pfam00047   7 TVLEGDSATLTCSASTGSPGPDVTWSKEGGtlieSLKVKHDNgrttqSSLLISNVTKEDAGTYTCVVNNPGGSATLST 84