BIT, an immune antigen receptor‐like molecule in the brain 1

• Published in: FEBS letters Vol. 411; no. 2-3; pp. 327 - 334
• Main Authors: Sano, Shin-ichiro, Ohnishi, Hiroshi, Omori, Akira, Hasegawa, Junko, Kubota, Misae
• Format: Journal Article
• Language: English
• Published: 14.07.1997
• Subjects: CHAPS, 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate; HEPES, N-2-hydroxyethylpiperazine-N′-ethanesulfonic acid; Immune antigen receptor-like molecule; Immunoglobulin superfamily; IRS-1, insulin receptor substrate-1; MHC, major histocompatibility complex; Neurite extension; PMSF, phenylmethylsulfonyl fluoride; Rat brain; SH2, src homology 2; TAM, tyrosine-based activation motif; TCR, T-cell receptor; Tyrosine phosphorylation
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/S0014-5793(97)00724-2

We previously found a brain‐specific glycoprotein in the rat brain. It postnatally increases and is rich in the mature brain. We cloned cDNA of this protein. It is composed of a signal peptide, a V‐type immunoglobulin domain, two C1‐type immunoglobulin domains, a transmembrane segment and a cytoplasmic region containing two tyrosine‐based activation motifs (TAM) that are variants of the antigen receptor signaling motifs. The overall structure is similar to those of immune antigen receptors. This molecule, BIT (brain immunoglobulin‐like molecule with TAMs), is a major endogenous substrates of brain tyrosine kinases in vitro. Cerebral cortical neurons could extend their neurites on BIT‐coated substrate and anti‐BIT monoclonal antibody specifically inhibited the effect. These findings and our recent study concerning BIT signal transduction mechanism suggest that BIT, an immune antigen receptor‐like molecule of the brain, functions as a membrane signaling molecule that may participate in cell–cell interaction.