STAB2

STAB2, also known as Stabilin-2, is a human gene that encodes a large type I transmembrane scavenger receptor expressed primarily on liver sinusoidal endothelial cells, with additional expression in spleen, lymph nodes, and other vascular beds. In many studies, the mouse ortholog is referred to as HARE (hyaluronan receptor for endocytosis); STAB2 and Stabilin-2 are central components of the hyaluronan scavenging system.

Stabilin-2 functions as an endocytic receptor that clears a broad range of ligands from the bloodstream. Its extracellular domain contains multiple motifs, including fasciclin-like and EGF-like repeats, enabling binding of hyaluronan and other glycosaminoglycans, as well as acetylated low-density lipoprotein, heparin, and advanced glycation end products. The receptor mediates clathrin-dependent endocytosis through its cytoplasmic tail, directing ligands to lysosomal degradation and contributing to vascular and tissue homeostasis by removing circulating macromolecules and aged extracellular matrix components.

Physiological and potential clinical relevance include maintenance of vascular and tissue homeostasis, clearance of extracellular matrix fragments, and involvement in remodeling processes. Altered STAB2 expression or function has been explored in the context of liver disease, aging, and inflammatory conditions, and the receptor is a subject of ongoing research in cancer biology and biomarker studies.

STAB2 belongs to the family of scavenger receptors and is closely related to STAB1 (Stabilin-1). See also Stabilin-1 and scavenger receptor pathways for related context.