Small proline-rich protein 2A (SPRR2A)

Small proline-rich protein 2A (SPRR2A) is a secreted, cysteine- and proline-rich protein expressed by epithelial cells—including Paneth and goblet cells of the intestine—and is phylogenetically distinct from other known mammalian antimicrobial proteins[1]. It is uniquely upregulated in the gut during type 2 immune responses, such as those induced by helminth infections, and selectively kills Gram-positive bacteria by binding to, and disrupting, their membranes via salt- and pH-dependent interactions with negatively charged membrane lipids[1]. SPRR2A helps shape the intestinal microbiota, restricts bacterial access to the intestinal surface, and prevents tissue invasion by bacteria, particularly during parasite infection[1]. Beyond its role in innate immunity, SPRR2A is overexpressed in several cancers, notably gastric cancer (where it is a promising serum biomarker), and may promote epithelial-mesenchymal transition and cell migration by inhibiting p53 acetylation, which is linked to tumor invasion and metastasis[2].

Other names

SPR-2A2-1small proline-rich protein 2ASPRR2A