Identification of FLRT1, FLRT2, and FLRT3:: A novel family of transmembrane leucine-rich repeat proteins

FLRT1, FLRTS, and FLRTS comprise a novel gene family isolated in a screen for extracellular matrix proteins expressed in muscle. The three genes encode putative type I transmembrane proteins, each containing 10 leucine-rich repeats flanked by N-terminal and C-terminal cysteine-rich regions, a fibronectin/ collagen-like domain, and an intracellular tail. FLRT1 is expressed in kidney and brain, FLRTS is expressed in pancreas, skeletal muscle, brain, and heart, and FLRTS is expressed in kidney, brain, pancreas, skeletal muscle, lung, liver, placenta, and heart. FLRT1 localized to 11q12-q13, FLRTS to 14q24-q32, and FLRT3 to 20p11, When expressed in SF9 and COSY cells, FLRT1 and FLRTS migrate as 90- and 85-kDa proteins, respectively, and both are glycosylated. Given the overall structure of the three proteins, a function in cell adhesion and/or receptor signaling is predicted. (C) 1999 Academic Press.