Golgi Glycoprotein 1 (GLG1)

MG-160, originally isolated from rat brain, is a conserved membrane sialoglycoprotein residing in the medial cisternae of the Golgi apparatus of most cells . The full-length cDNA encodes a predicted 1,179-amino acid protein that has a signal peptide, a proline- and glutamine-rich region, a cysteine-rich domain containing 5 potential asparagine-linked glycosylation sites, a hydrophobic transmembrane domain, and a short carboxy-terminal tail. The proline- and glutamine-rich segment contains a polyglutamine stretch which is encoded by an uninterrupted exonic sequence of CAG-CAA repeats. Human GLG1 shows between 88% and 95% overall amino acid identity with rat Glg1, mouse Esl1, and chicken CRF. The authors detected 3 transcripts of 10, 5, and 3.8 kb in several human fetal and adult tissues by Northern blot analysis.