Acid ceramidase (AC) (ACDase) (Acid CDase) (EC 3.5.1.23) (Acylsphingosine deacylase) (N-acylethanolamine hydrolase ASAH1) (EC 3.5.1.-) (N-acylsphingosine amidohydrolase) (Putative 32 kDa heart protein) (PHP32) [Cleaved into: Acid ceramidase subunit alpha; Acid ceramidase subunit beta]
1_MPGRS 6_ CVALV 11_ LLAAA 16_ VSCAV 21_ AQHAP 26_ PWTED 31_ CRKST 36_ YPPSG 41_ PTYRG 46_ AVPWY 51_ TINLD 56_ LPPYK 61_ RWHEL 66_ MLDKA 71_ PVLKV 76_ IVNSL 81_ KNMIN 86_ TFVPS 91_ GKIMQ 96_ VVDEK 101_ LPGLL 106_ GNFPG 111_ PFEEE 116_ MKGIA 121_ AVTDI 126_ PLGEI 131_ ISFNI 136_ FYELF 141_ TICTS 146_ IVAED 151_ KKGHL 156_ IHGRN 161_ MDFGV 166_ FLGWN 171_ INNDT 176_ WVITE 181_ QLKPL 186_ TVNLD 191_ FQRNN 196_ KTVFK 201_ ASSFA 206_ GYVGM 211_ LTGFK 216_ PGLFS 221_ LTLNE 226_ RFSIN 231_ GGYLG 236_ ILEWI 241_ LGKKD 246_ VMWIG 251_ FLTRT 256_ VLENS 261_ TSYEE 266_ AKNLL 271_ TKTKI 276_ LAPAY 281_ FILGG 286_ NQSGE 291_ GCVIT 296_ RDRKE 301_ SLDVY 306_ ELDAK 311_ QGRWY 316_ VVQTN 321_ YDRWK 326_ HPFFL 331_ DDRRT 336_ PAKMC 341_ LNRTS 346_ QENIS 351_ FETMY 356_ DVLST 361_ KPVLN 366_ KLTVY 371_ TTLID 376_ VTKGQ 381_ FETYL 386_RDCPD
1: Lysosomal ceramidase that hydrolyzes sphingolipid ceramides into sphingosine and free fatty acids at acidic pH (PubMed:10610716, PubMed:11451951, PubMed:15655246, PubMed:26898341, PubMed:36752535, PubMed:7744740, PubMed:7852294). 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 (PubMed:10610716). Has a higher catalytic efficiency towards C12-ceramides versus other ceramides (PubMed:15655246, PubMed:7744740). Also catalyzes the reverse reaction allowing the synthesis of ceramides from fatty acids and sphingosine (PubMed:12764132, PubMed:12815059). 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 (PubMed:12764132). Also has an N-acylethanolamine hydrolase activity (PubMed:15655246). By regulating the levels of ceramides, sphingosine and sphingosine-1-phosphate in the epidermis, mediates the calcium-induced differentiation of epidermal keratinocytes (PubMed:17713573). 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 (PubMed:22261821)
2: May directly regulate steroidogenesis by binding the nuclear receptor NR5A1 and negatively regulating its transcriptional activity