Regulatory subunit of glucosidase II that cleaves sequentially the 2 innermost alpha-1,3-linked glucose residues from the Glc(2)Man(9)GlcNAc(2) oligosaccharide precursor of immature glycoproteins (PubMed:10929008). Required for efficient PKD1/Polycystin-1 biogenesis and trafficking to the plasma membrane of the primary cilia (By similarity). Glycan metabolism; N-glycan metabolism. Heterodimer of a catalytic alpha subunit (GANAB) and a beta subunit (PRKCSH) (PubMed:10929008). Binds glycosylated PTPRC (By similarity). The disease is caused by variants affecting the gene represented in this entry.