Current and Novel Aspects on the Non-lysosomal β-Glucosylceramidase GBA2

The non-lysosomal β-glucosylceramidase GBA2 (EC3.2.1.45, GH116) is ubiquitously expressed in various mammal tissues and cell types where it catalyzes the hydrolysis of glucosylceramide into glucose and ceramide. Although it has been known for many years that the central nervous system is the main site of GBA2 expression and activity, little information has been available so far on the role of this protein in the neuronal development, senescence and homeostasis. In the present review, we summarize the state-of-the art of this enzyme and in particular, we focus on the current knowledge on its structure, its physico-chemical properties and its subcellular localization. Data on the involvement of GBA2 in physiopathological processes are also described, with particular emphasis on the studies that have indicated the direct involvement of GBA2 in neuronal development and neurological disorders. A discussion of some open questions and future perspectives related to GBA2 are finally reported. We conclude that further investigations on this β-glucosylceramidase will provide new clues about the physiology of the central nervous system.