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CD275; ICOS ligand; B7 homolog 2; B7-H2; B7-like protein Gl50; B7-related protein 1; B7RP-1 (ICOSLG, B7H2, B7RP1, ICOSL, KIAA0653)
Function:
- ligand for the T-cell-specific cell surface receptor ICOS
- acts as a costimulatory signal for T-cell proliferation & cytokine secretion
- induces also B-cell proliferation & differentiation into plasma cells.
- may play role in mediating local tissue responses to inflammatory conditions, as well as in modulating the secondary immune response by co- stimulating memory T-cell function
Structure:
- belongs to the immunoglobulin superfamily, BTN/MOG family
- contains 1 Ig-like C2-type domain
- contains 1 Ig-like V-type domain
Compartment:
- membrane; single-pass type 1 membrane protein (putative)
Alternative splicing:
- named isoforms=2
- additional isoforms seem to exist
Expression:
- isoform 1 is widely expressed (brain, heart, kidney, liver, lung, pancreas, placenta, skeletal muscle, bone marrow, colon, ovary, prostate, testis, lymph nodes, leukocytes, spleen, thymus & tonsil)
- isoform 2 is detected only in lymph nodes, leukocytes & spleen
- expressed on activated monocytes & dendritic cells
- constitutive expression is further enhanced by TNF in peripheral blood B-cells & monocytes
- TNF decreases expression in dendritic cells
Interactions
molecular events
General
cluster-of-differentiation antigen; cluster designation antigen; CD antigen
immunoglobulin superfamily protein
Properties
SIZE: entity length = 302 aa
MW = 33 kD
COMPARTMENT: cellular membrane
MOTIF: signal sequence {1-18}
immunoglobulin superfamily domain {19-129}
MOTIF: cysteine residue {C37}
MODIFICATION: cysteine residue {C113}
N-glycosylation site {N70}
N-glycosylation site {N102}
cysteine residue {C113}
MODIFICATION: cysteine residue {C37}
N-glycosylation site {N137}
immunoglobulin superfamily domain {141-227}
MOTIF: cysteine residue {C158}
MODIFICATION: cysteine residue {C216}
N-glycosylation site {N173}
N-glycosylation site {N186}
cysteine residue {C216}
MODIFICATION: cysteine residue {C158}
N-glycosylation site {N225}
transmembrane domain {257-277}
Database Correlations
OMIM 605717
UniProt O75144
PFAM correlations
Entrez Gene 23308
Kegg hsa:23308
References
- Uniprot :accession O75144
Component-of
molecular complex