V-set domain-containing T-cell activation inhibitor 1; immune costimulatory protein B7-H4; B7h.5; T-cell costimulatory molecule B7x; protein B7S1 (VTCN1, B7H4, UNQ659/PRO1291)

Function: - negatively regulates T-cell-mediated immune response by inhibiting T-cell activation, proliferation, cytokine production & development of cytotoxicity - when expressed on the cell surface of tumor macrophages, plays an important role, together with regulatory T-cells in suppression of tumor-associated antigen-specific T-cell immunity - role in promoting epithelial cell transformation - N-glycosylated Structure: - belongs to the immunoglobulin superfamily, BTN/MOG family - contains 2 Ig-like V-type domain (immunoglobulin-like) Compartment: - cell membrane - expressed at the cell surface - soluble form has also been detected Alternative splicing: named isoforms=3 Expression: - widely expressed, including in kidney, liver, lung, ovary, placenta, spleen & testis - expressed on activated T- & B-cells, monocytes & dendritic cells, but not expressed in most normal tissues (at protein level) - up-regulated by IL-6 & IL-10 & inhibited by GM-CSF & IL-4 on antigen-presenting cells (APCs) Pathology: - overexpressed in breast cancer, ovarian cancer, endometrial cancer, renal cell carcinoma & non-small-cell lung cancers - may serve as a predictive marker for renal cell carcinoma Comparative biology: - the mouse ortholog is a GPI-anchored protein but the Gly which is predicted to be the modified site in mouse & rat is not conserved in human

General

evolutionary divergent protein glycoprotein membrane protein

Properties

SIZE: entity length = 282 aa MW = 31 kD COMPARTMENT: plasma membrane MOTIF: signal sequence {1-24} immunoglobulin superfamily domain {35-146} MOTIF: cysteine residue {C56} MODIFICATION: cysteine residue {C130} cysteine residue {C130} MODIFICATION: cysteine residue {C56} immunoglobulin superfamily domain {153-241} MOTIF: cysteine residue {C168} MODIFICATION: cysteine residue {C225} N-glycosylation site {N216} cysteine residue {C225} MODIFICATION: cysteine residue {C168} transmembrane domain {260-280}

Database Correlations

OMIM 608162 UniProt Q7Z7D3 Pfam PF07686 Kegg hsa:7967

References

UniProt :accession Q7Z7D3