Golgi Class I Mannosidases IA, IB, IC

Golgi class I mannosidases (specifically IA, IB, and IC) are a group of exo-acting α-1,2-mannosidase enzymes located in the Golgi apparatus. They play a critical role in the processing of N-linked glycans during glycoprotein maturation and quality control within eukaryotic cells. These mannosidases trim mannose residues from high-mannose oligosaccharides on glycoproteins as they transit through the early secretory pathway, converting Man_8GlcNAc_2 to Man_5GlcNAc_2. This trimming step is essential for subsequent formation of complex or hybrid N-glycan structures. By modifying N-glycans on misfolded proteins, these enzymes also help tag such proteins for ER-associated degradation (ERAD), thus contributing to cellular protein quality control mechanisms. Alterations in expression or function affect cell growth, adhesion, motility, and protein phosphorylation due to changes in glycosylation patterns, and have been implicated in diseases such as cancer and kidney disorders.

Other names

MAN1A1MAN1A2MAN1C1Golgi α-mannosidase IAGolgi α-mannosidase IBGolgi α-mannosidase IC