Rabbit polyclonal antibody to Glucosidase IIβ (K117)

Trimming of glucoses from N~linked core glycans on newly synthesized glycoproteins occurs sequentially through the action of Glucosidases I and II in the endoplasmic reticulum (ER). Glucosidase II is an ER~localized enzyme that contains α and β subunits (Glucosidase IIα and Glucosidase IIβ). The α and β subunits form a defined heterodimeric complex with a molecular weight about 161 kDa. Glucosidase IIα is the catalyitc core of the enzyme and can function independently of the β subunit. The sequence of Glucosidase IIβ encodes protein rich in glutamic and aspartic acid with a putative ER retention signal (HDEL) at the C terminus. The phosphorylated form of Glucosidase IIβ is localized in the plasma membrane and is highly expressed in FGF stimulated fibroblasts and epidermal carcinoma cells. Glucosidase IIβ was first purified from a human carcinoma cell line as a potential substrate for protein kinase C. Through the HDEL signal at the C~terminus, Glucosidase IIβ retains the complete complex in the ER.