BIT, an immune antigen receptor-like molecule in the brain.
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.
Sano
S
S
Mitsubishi Kasei Institute of Life Sciences, Tokyo, Japan. ssano@libra.ls.m-kagaku.co.jp
Ohnishi
H
H
Omori
A
A
Hasegawa
J
J
Kubota
M
M
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal; D000943:Antigens, Differentiation; D001483:Base Sequence; D015152:Blotting, Northern; D001921:Brain / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D002478:Cells, Cultured; D003001:Cloning, Molecular; D015151:Immunoblotting; D007797:Laminin / Q000378:metabolism; D008562:Membrane Glycoproteins; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000737:chemistry / Q000502:physiology*; D039842:Neural Cell Adhesion Molecule L1; D016501:Neurites / Q000648:ultrastructure; D009474:Neurons / Q000166:cytology; D019000:Phosphotyrosine / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D011971:Receptors, Immunologic / Q000737:chemistry / Q000502:physiology*; D016415:Sequence Alignment; D015398:Signal Transduction / Q000502:physiology
D000911:Antibodies, Monoclonal; D000943:Antigens, Differentiation; D007797:Laminin; D008562:Membrane Glycoproteins; D009419:Nerve Tissue Proteins; D039842:Neural Cell Adhesion Molecule L1; D012333:RNA, Messenger; D011971:Receptors, Immunologic; D019000:Phosphotyrosine; D011505:Protein-Tyrosine Kinases