| IED ID | IndEnz0002008375 |
| Enzyme Type ID | protease008375 |
| Protein Name |
Prosaposin Proactivator polypeptide Cleaved into: Saposin-A Protein A ; Saposin-B-Val; Saposin-B Cerebroside sulfate activator CSAct Dispersin Sphingolipid activator protein 1 SAP-1 Sulfatide/GM1 activator ; Saposin-C A1 activator Co-beta-glucosidase Glucosylceramidase activator Sphingolipid activator protein 2 SAP-2 ; Saposin-D Component C Protein C |
| Gene Name | PSAP GLBA SAP1 |
| Organism | Homo sapiens (Human) |
| Taxonomic Lineage | cellular organisms Eukaryota Opisthokonta Metazoa Eumetazoa Bilateria Deuterostomia Chordata Craniata Vertebrata Gnathostomata (jawed vertebrates) Teleostomi Euteleostomi Sarcopterygii Dipnotetrapodomorpha Tetrapoda Amniota Mammalia Theria Eutheria Boreoeutheria Euarchontoglires Primates Haplorrhini Simiiformes Catarrhini Hominoidea (apes) Hominidae (great apes) Homininae Homo Homo sapiens (Human) |
| Enzyme Sequence | MYALFLLASLLGAALAGPVLGLKECTRGSAVWCQNVKTASDCGAVKHCLQTVWNKPTVKSLPCDICKDVVTAAGDMLKDNATEEEILVYLEKTCDWLPKPNMSASCKEIVDSYLPVILDIIKGEMSRPGEVCSALNLCESLQKHLAELNHQKQLESNKIPELDMTEVVAPFMANIPLLLYPQDGPRSKPQPKDNGDVCQDCIQMVTDIQTAVRTNSTFVQALVEHVKEECDRLGPGMADICKNYISQYSEIAIQMMMHMQPKEICALVGFCDEVKEMPMQTLVPAKVASKNVIPALELVEPIKKHEVPAKSDVYCEVCEFLVKEVTKLIDNNKTEKEILDAFDKMCSKLPKSLSEECQEVVDTYGSSILSILLEEVSPELVCSMLHLCSGTRLPALTVHVTQPKDGGFCEVCKKLVGYLDRNLEKNSTKQEILAALEKGCSFLPDPYQKQCDQFVAEYEPVLIEILVEVMDPSFVCLKIGACPSAHKPLLGTEKCIWGPSYWCQNTETAAQCNAVEHCKRHVWN |
| Enzyme Length | 524 |
| Uniprot Accession Number | P07602 |
| Absorption | |
| Active Site | |
| Activity Regulation | |
| Binding Site | |
| Calcium Binding | |
| catalytic Activity | |
| DNA Binding | |
| EC Number | |
| Enzyme Function | FUNCTION: Saposin-A and saposin-C stimulate the hydrolysis of glucosylceramide by beta-glucosylceramidase (EC 3.2.1.45) and galactosylceramide by beta-galactosylceramidase (EC 3.2.1.46). Saposin-C apparently acts by combining with the enzyme and acidic lipid to form an activated complex, rather than by solubilizing the substrate.; FUNCTION: Saposin-B stimulates the hydrolysis of galacto-cerebroside sulfate by arylsulfatase A (EC 3.1.6.8), GM1 gangliosides by beta-galactosidase (EC 3.2.1.23) and globotriaosylceramide by alpha-galactosidase A (EC 3.2.1.22). Saposin-B forms a solubilizing complex with the substrates of the sphingolipid hydrolases.; FUNCTION: Saposin-D is a specific sphingomyelin phosphodiesterase activator (EC 3.1.4.12).; FUNCTION: [Prosaposin]: Behaves as a myelinotrophic and neurotrophic factor, these effects are mediated by its G-protein-coupled receptors, GPR37 and GPR37L1, undergoing ligand-mediated internalization followed by ERK phosphorylation signaling. {ECO:0000250|UniProtKB:Q61207, ECO:0000269|PubMed:10383054}.; FUNCTION: Saposins are specific low-molecular mass non-enzymic proteins, they participate in the lysosomal degradation of sphingolipids, which takes place by the sequential action of specific hydrolases. |
| Temperature Dependency | |
| PH Dependency | |
| Pathway | |
| nucleotide Binding | |
| Features | Alternative sequence (2); Beta strand (1); Chain (6); Disulfide bond (12); Domain (6); Glycosylation (5); Helix (20); Mutagenesis (1); Natural variant (7); Propeptide (5); Sequence conflict (1); Signal peptide (1); Site (1); Turn (1) |
| Keywords | 3D-structure;Alternative splicing;Direct protein sequencing;Disease variant;Disulfide bond;Gangliosidosis;Gaucher disease;Glycoprotein;Leukodystrophy;Lipid metabolism;Lysosome;Metachromatic leukodystrophy;Reference proteome;Repeat;Secreted;Signal;Sphingolipid metabolism |
| Interact With | P05067; Q92624; P31944; P48730-2; P28799; P07948; P50542-3; O96006; Itself; P55072 |
| Induction | |
| Subcellular Location | SUBCELLULAR LOCATION: Lysosome {ECO:0000269|PubMed:14657016, ECO:0000269|PubMed:21835174, ECO:0000269|PubMed:22431521}.; SUBCELLULAR LOCATION: [Prosaposin]: Secreted {ECO:0000250|UniProtKB:Q61207}. Note=Secreted as a fully glycosylated 70 kDa protein composed of complex glycans. {ECO:0000250|UniProtKB:Q61207}. |
| Modified Residue | |
| Post Translational Modification | PTM: The lysosomal precursor is proteolytically processed to 4 small peptides, which are similar to each other and are sphingolipid hydrolase activator proteins.; PTM: N-linked glycans show a high degree of microheterogeneity. {ECO:0000269|PubMed:19159218, ECO:0000269|PubMed:19167329}.; PTM: The one residue extended Saposin-B-Val is only found in 5% of the chains. |
| Signal Peptide | SIGNAL 1..16; /evidence="ECO:0000269|PubMed:1958198, ECO:0000269|PubMed:8323276, ECO:0007744|PubMed:25944712" |
| Structure 3D | NMR spectroscopy (2); X-ray crystallography (14) |
| Cross Reference PDB | 1M12; 1N69; 1SN6; 2DOB; 2GTG; 2QYP; 2R0R; 2R1Q; 2RB3; 2Z9A; 3BQP; 3BQQ; 4DDJ; 4UEX; 4V2O; 6SLR; |
| Mapped Pubmed ID | 10781797; 11734895; 12083803; 12813057; 14630798; 14674747; 14716313; 15231748; 15305334; 15548330; 15713488; 15897971; 16080200; 16169070; 16385451; 16713569; 16823039; 17044040; 17110338; 17171640; 17300216; 17372201; 17561962; 17712477; 17893707; 17961073; 18453694; 18462685; 18481277; 18577758; 18761669; 19224915; 19267410; 19581582; 20132547; 20217867; 20379614; 20484222; 20711500; 21328455; 21555518; 21743296; 21900206; 21943334; 22308394; 22738294; 23414517; 23416715; 23417432; 23690594; 24070323; 24657443; 24872419; 24966325; 2534964; 25640309; 25926625; 26045750; 26144235; 26341737; 26462614; 26616259; 26831127; 27356620; 2748346; 2834384; 28541286; 29249381; 30385233; 30632081; 30953361; 31368365; 31864418; 32044242; 32201884; 33197249; 33219486; 34374777; 3456607; 8015379; 8692836; 8889578; |
| Motif | |
| Gene Encoded By | |
| Mass | 58,113 |
| Kinetics | |
| Metal Binding | |
| Rhea ID | |
| Cross Reference Brenda |