BTNL9

Butyrophilin (BTN) and butyrophilin-like (BTNL) proteins share significant homology and structural features with B7-molecules and like B7-molecules consist of regulatory molecules that modulate T-cell mediated immune responses. Butyrophilin-like 9 (BTNL9) is a member of the BTN/MOG Ig-superfamily and functions as a negative regulator of immune cell activation. Human BTNL9 is a 535 amino acid (aa) type I transmembrane glycoprotein that contains a 222 aa extracellular domain (ECD), a 21 aa helical transmembrane domain, and a 258 aa cytoplasmic domain.