Stomatin

Stomatin is a small integral membrane protein of the band 7 (SPFH) domain-containing family. In humans it is encoded by the STOM gene. Stomatin was first identified as a prominent component of the erythrocyte membrane and later found in many other cell types. The protein is anchored to the inner leaflet of the plasma membrane by a hairpin-like transmembrane region, with cytoplasmic N- and C-termini and a central conserved stomatin domain that mediates oligomerization. This propensity for self-association leads stomatin to form oligomeric complexes, which are thought to organize lipid rafts and create scaffolding platforms for other membrane proteins.

Stomatin is broadly expressed and enriched in red blood cells and platelets, but it is found in various tissues. Functionally, it is regarded as a regulator of membrane protein activity rather than a transporter itself. It modulates the function of several ion channels and transporters and participates in the organization of membrane microdomains. Through interactions with raft-associated proteins and, possibly, the cytoskeleton, stomatin can influence membrane curvature and protein trafficking.

Altered stomatin expression or function has been associated with changes in erythrocyte membrane properties and has been studied in relation to some hereditary membrane disorders. Its evolutionary conservation across eukaryotes and its membership in the band 7/SPFH family highlight its role in membrane organization and protein regulation.

See also: SPFH domain, band 7 family, lipid raft.