V-set and immunoglobulin domain-containing protein 1 (VSIG1)

V-set and immunoglobulin domain-containing protein 1 (VSIG1) is a type I transmembrane protein and a member of the immunoglobulin superfamily (IgSF), belonging specifically to the junctional adhesion molecule (JAM) family[1][2][3]. VSIG1 is characterized by two extracellular immunoglobulin-like domains, a single transmembrane region, and a short cytoplasmic tail with multiple phosphorylation sites[1][3]. In normal human tissues, VSIG1 is primarily expressed in the gastric mucosa and testis, where it is implicated in the maintenance of epithelial integrity and cell differentiation via localization at adherens and tight junctions[1][2][3]. VSIG1 acts as a tumor suppressor—its expression in gastric cancers is associated with a more favorable prognosis and decreased cell proliferation, migration, and invasion[2]. It is also expressed (often in a tissue-restricted manner) in subsets of lung, pancreatic, ovarian, prostate, colon, and hepatocellular carcinomas, where it may serve as a biomarker for certain histological subtypes or lineage[1][2]. Functional studies have shown that elevated VSIG1 reduces tumor cell proliferation and invasion, likely by modulating cell–cell adhesion[2]. There are multiple alternatively spliced isoforms of VSIG1, some of which are tissue specific, as seen in mouse testis[1]. No direct interacting drugs or therapeutic agents targeting VSIG1 have been reported to date, nor are any mechanisms of action for pharmacological targeting established. As a biomarker, VSIG1 is considered for distinguishing gastric-type differentiation and for prognosis in gastric cancer[1][2][3]. Overall, while VSIG1 has no known direct exogenous modulators, it is considered a promising tumor suppressor and biomarker in cancer, particularly linked to cell adhesion and maintenance of epithelial cellular architecture[2][4].

Other names

GPA34MGC44287Cell surface A33 antigenGlycoprotein A341700062D20RikdJ889N15.1