Mannosyl Alpha-1,3-Glycoprotein Beta-1,4-N-Acetylglucosaminyltransferase Isozyme C (MGAT4C)

The deduced 478-amino acid protein has a calculated molecular mass of 55 kD. It contains a highly hydrophobic N-terminal region, which may be a transmembrane domain, and a hydrophilic region, which may be a stem region.

GNT-IV-H lacks the proline-rich stem sequence found in other N-acetylglucosaminyltransferases. Northern blot analysis of multiple tissues revealed a 3.8-kb transcript expressed in heart and in adult and fetal brain. Transcripts of 2.8 and 1.7 kb were detected in testis. RT-PCR revealed abundant expression of an alternatively spliced transcript in brain, with trace amounts in liver and adrenal gland. This transcript lacks exon 3 and has an in-frame stop codon upstream of the predicted initiation codon.