Cytosolic beta-Glucosidase/GBA3: Proteins and Enzymes

There are three beta-glucosidases (GBA) in human genome. GBA1 endodes a lysosomal membrane protein that cleaves the beta-glucosidic linkage of glucosylceramide. GBA2 encodes a microsomal beta-glucosidase that catalyzes the hydrolysis of bile acid 3-O-glucosides. GBA3 is a cytosolic beta-glucosidase and is predominantly expressed in liver. GBA3 efficiently hydrolyzes beta-D-glucoside and beta-D-galactoside, but not any known physiological beta-glycoside, suggesting that it may be involved in detoxification of plant glycosides. GBA3 also has significant neutral glycosylceramidase activity, suggesting that it may be involved in a nonlysosomal catabolic pathway of glucosylceramide metabolism. At the protein level, GBA3 shows significant homology (>40%) with Klotho protein that is known for its association with aging process.