Molecular cloning of human myelin‐associated glycoprotein

Abstract

The nucleotide sequence for human myelin‐associated glycoprotein (MAG) and its deduced amino acid sequence, obtained by analysis of two overlapping cDNA clones isolated from a human brain cDNA library, is presented and compared to that reported for rat MAG.The sequence provides an open reading frame of 1,878 nucleotides encoding a peptide of 626 amino acids with a calculated molecular weight of 69.1 kD. It is 89% homologous in nucleotide sequence to the large isoform of rat MAG, with 95% homology in the amino acid sequence. It contains 9 potential glycosylation sites, one more than in rat, and shares other key features with rat MAG, including 5 immunoglobulin‐like regions of internal homology, an RGD sequence, and potential phosphorylation sites. Its structure appears to be highly conserved in evolution, possibly suggesting a close interdependence between its structure and function. The human gene is located on the proximal long arm of chromosome 19 (19q12 → q13.2).