Non-lysosomal glucosylceramidase that catalyzes the hydrolysis of glucosylceramides/GlcCers (such as beta-D-glucosyl-(1<->1')-N-acylsphing-4-enine) to free glucose and ceramides (such as N-acylsphing-4-enine) (PubMed:17080196, PubMed:23250757). GlcCers are membrane glycosphingolipids that have a wide intracellular distribution (PubMed:23250757). They are the main precursors of more complex glycosphingolipids that play a role in cellular growth, differentiation, adhesion, signaling, cytoskeletal dynamics and membrane properties (PubMed:25803043). Also involved in the transglucosylation of cholesterol, transferring glucose from GlcCer, thereby modifying its water solubility and biological properties (PubMed:26724485, PubMed:32144204). Under specific conditions, may catalyze the reverse reaction, transferring glucose from cholesteryl-3-beta-D-glucoside to ceramide (such as N-acylsphing-4-enine) (PubMed:26724485, PubMed:32144204). May play a role in the metabolism of bile acids (PubMed:17080196). Able to hydrolyze bile acid 3-O-glucosides as well as to produce bile acid-glucose conjugates thanks to a bile acid glucosyl transferase activity (PubMed:17080196). Catalyzes the hydrolysis of galactosylceramides/GalCers (such as beta-D-galactosyl-(1<->1')-N-acylsphing-4-enine), as well as galactosyl transfer between GalCers and cholesterol in vitro with lower activity compared with their activity against GlcCers (PubMed:32144204). a beta-D-glucosyl-(1<->1')-N-acylsphing-4-enine + H2O = an N-acylsphing-4-enine + D-glucose a beta-D-galactosyl-(1<->1')-N-acylsphing-4-enine + H2O = an N-acylsphing-4-enine + D-galactose beta-D-glucosyl-(1->3)-O-lithocholate + H2O = D-glucose + lithocholate beta-D-glucosyl-(1->3)-O-chenodeoxycholate + H2O = chenodeoxycholate + D-glucose a dolichyl beta-D-glucosyl phosphate + chenodeoxycholate = a dolichyl phosphate + beta-D-glucosyl-(1->3)-O-chenodeoxycholate + H(+) chenodeoxycholate + octyl beta-D-glucose = beta-D-glucosyl-(1->3)-O-chenodeoxycholate + octan-1-ol cholesteryl 3-beta-D-glucoside + H2O = cholesterol + D-glucose a beta-D-glucosyl-(1<->1')-N-acylsphing-4-enine + cholesterol = an N-acylsphing-4-enine + cholesteryl 3-beta-D-glucoside beta-D-glucosyl-N-(9Z-octadecenoyl)-sphing-4E-enine + cholesterol = cholesteryl 3-beta-D-glucoside + N-(9Z-octadecenoyl)-sphing-4-enine a beta-D-galactosyl-(1<->1')-N-acylsphing-4-enine + cholesterol = an N-acylsphing-4-enine + cholesteryl 3-beta-D-galactoside 1-(beta-D-galactosyl)-N-dodecanoylsphing-4-enine + cholesterol = cholesteryl 3-beta-D-galactoside + N-dodecanoylsphing-4-enine Enzymatic activity is dependent on membrane association and requires the presence of lipids (PubMed:23250757). Inhibited by N-(adamantanemethyloxypentyl)-deoxynojirimycin/AMP-DNM (PubMed:26724485). Inhibited by its product sphingosine/N-acylsphing-4-enine in a feedback loop (PubMed:28258214). Also inhibited by other non-acetylated sphingoid bases and their derivatives but not by sphingosine-1-phosphate and complex sphingolipids (PubMed:28258214). Optimum pH is between 6.0 and 7.0. Lipid metabolism; sphingolipid metabolism. Steroid metabolism; cholesterol metabolism. Localization to the plasma membrane and alternative topologies have also been reported. Widely expressed at low level (PubMed:17080196). Highly expressed in testis and brain (PubMed:17080196). Ubiquitously expressed in the brain (at protein level) (PubMed:23250757). Expressed by Sertoli cells (at protein level) (PubMed:17080196). Homozygous knockout mice display an accumulation of glucosylceramides in testis, brain and liver (PubMed:17080196). The accumulation of glucosylceramides in Sertoli cells alters sperm shape and males exhibit impaired fertility (PubMed:17080196). Despite the bile acid glucosidase and transferase activities measured in vitro, bile acid metabolism is normal in knockout mice (PubMed:17080196). No obvious neurological symptoms, organomegaly or lifespan alteration are observed (PubMed:17080196). Cholesterol metabolism and protein glycosylation are also normal in these mice (PubMed:17080196). Belongs to the non-lysosomal glucosylceramidase family.