Lysosome . Secreted . Secretion is extremely low and localization to lysosomes is mannose-6-phosphate receptor-dependent. .; [Isoform 2]: Nucleus . Cytoplasm . A localization to the nucleus and the cytoplasm has also been reported for ASAH1, most probably for isoforms devoid of a signal peptide. .
Tissue Expression
Broadly expressed with higher expression in heart.
Signaling_pathway
Cellular Processes >> Transport and catabolism >> Lysosome;Environmental Information Processing >> Signal transduction >> Sphingolipid signaling pathway
Research Areas
Function
Lysosomal ceramidase that hydrolyzes sphingolipid ceramides into sphingosine and free fatty acids at acidic pH . Ceramides, sphingosine, and its phosphorylated form sphingosine-1-phosphate are bioactive lipids that mediate cellular signaling pathways regulating several biological processes including cell proliferation, apoptosis and differentiation . Has a higher catalytic efficiency towards C12-ceramides versus other ceramides . Also catalyzes the reverse reaction allowing the synthesis of ceramides from fatty acids and sphingosine . For the reverse synthetic reaction, the natural sphingosine D-erythro isomer is more efficiently utilized as a substrate compared to D-erythro-dihydrosphingosine and D-erythro-phytosphingosine, while the fatty acids with chain lengths of 12 or 14 carbons are the most efficiently used . Has also an N-acylethanolamine hydrolase activity . By regulating the levels of ceramides, sphingosine and sphingosine-1-phosphate in the epidermis, mediates the calcium-induced differentiation of epidermal keratinocytes . Also indirectly regulates tumor necrosis factor/TNF-induced apoptosis (By similarity). By regulating the intracellular balance between ceramides and sphingosine, in adrenocortical cells, probably also acts as a regulator of steroidogenesis .; [Isoform 2]: May directly regulate steroidogenesis by binding the nuclear receptor NR5A1 and negatively regulating its transcriptional activity.