Identification of tyrosine 620 as the major phosphorylation site of myelin-associated glycoprotein and its implication in interacting with signaling molecules

• Published in: The Journal of biological chemistry Vol. 269; no. 44; pp. 27240 - 27245
• Main Authors: Jaramillo, M L, Afar, D E, Almazan, G, Bell, J C
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 04.11.1994; American Society for Biochemistry and Molecular Biology
• Subjects: Animals; Base Sequence; DNA Primers - chemistry; Mice; Molecular Sequence Data; Myelin Proteins - metabolism; Myelin-Associated Glycoprotein; Nerve Fibers, Myelinated - metabolism; Oligodendroglia - metabolism; Peptide Mapping; Phosphorylation; Phosphotyrosine; Proto-Oncogene Proteins - metabolism; Proto-Oncogene Proteins c-fyn; Rats; Recombinant Proteins; Signal Transduction; Type C Phospholipases - metabolism; Tyrosine - analogs & derivatives; Tyrosine - metabolism
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1016/S0021-9258(18)46974-8

Myelin-associated glycoprotein (MAG) is a myelin-specific cell adhesion molecule of the immunoglobulin supergene family and is tyrosine-phosphorylated in the developing brain. To define the role of MAG in signal transduction, the tyrosine phosphorylation sites were analyzed. The major tyrosine phosphorylation residue was identified as Tyr-620, which was found to interact specifically with the SH2 domains of phospholipase C (PLC gamma). This domain may represent a novel protein binding motif that can be regulated by tyrosine phosphorylation. MAG also specifically bound the Fyn tyrosine kinase, suggesting that MAG serves as a docking protein that allows the interaction between different signaling molecules.