O13035 · SAP_CHICK
- ProteinProsaposin
- GenePSAP
- StatusUniProtKB reviewed (Swiss-Prot)
- Organism
- Amino acids518 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score4/5
Function
function
The lysosomal degradation of sphingolipids takes place by the sequential action of specific hydrolases. Some of these enzymes require specific low-molecular mass, non-enzymatic proteins: the sphingolipids activator proteins (coproteins).
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.
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.
Saposin-D is a specific sphingomyelin phosphodiesterase activator (EC 3.1.4.12).
GO annotations
all annotations | all molecular function | virus receptor activity | dna binding | rna binding | cytoskeletal motor activity | catalytic activity | gtpase activity | structural molecule activity | transporter activity | cytoskeletal protein binding | lipid binding | cyclase activity | antioxidant activity | oxidoreductase activity | transferase activity | hydrolase activity | lyase activity | isomerase activity | ligase activity | protein tag activity | cargo receptor activity | histone binding | protein folding chaperone | translation regulator activity | nutrient reservoir activity | receptor ligand activity | molecular transducer activity | molecular adaptor activity | toxin activity | cell adhesion mediator activity | molecular function regulator activity | virus coreceptor activity | catalytic activity, acting on a protein | catalytic activity, acting on dna | catalytic activity, acting on rna | molecular carrier activity | transcription regulator activity | general transcription initiation factor activity | molecular sensor activity | molecular sequestering activity | atp-dependent activity | other molecular function | all biological process | mitotic cell cycle | cytokinesis | cytoplasmic translation | immune system process | muscle system process | circulatory system process | renal system process | respiratory system process | carbohydrate metabolic process | generation of precursor metabolites and energy | dna replication | dna repair | dna recombination | chromatin organization | dna-templated transcription | regulation of dna-templated transcription | trna metabolic process | protein folding | protein glycosylation | amino acid metabolic process | modified amino acid metabolic process | lipid metabolic process | vitamin metabolic process | sulfur compound metabolic process | intracellular protein transport | nucleocytoplasmic transport | autophagy | inflammatory response | mitochondrion organization | cytoskeleton organization | microtubule-based movement | peroxisome organization | lysosome organization | chromosome segregation | cell adhesion | establishment or maintenance of cell polarity | programmed cell death | photosynthesis | mrna metabolic process | snrna metabolic process | vesicle-mediated transport | reproductive process | digestive system process | signaling | cell differentiation | protein catabolic process | extracellular matrix organization | regulatory ncrna-mediated gene silencing | telomere organization | cell junction organization | wound healing | ribosome biogenesis | cilium organization | anatomical structure development | cell motility | nervous system process | endocrine process | protein maturation | transmembrane transport | nucleobase-containing small molecule metabolic process | hepaticobiliary system process | membrane organization | protein-containing complex assembly | cell wall organization or biogenesis | nitrogen cycle metabolic process | protein localization to plasma membrane | defense response to other organism | detoxification | meiotic nuclear division | mitotic nuclear division | mitochondrial gene expression | carbohydrate derivative metabolic process | other biological process | all cellular component | nuclear chromosome | extracellular region | extracellular space | cell wall | nucleus | nuclear envelope | nucleoplasm | chromosome | nucleolus | mitochondrion | lysosome | endosome | vacuole | peroxisome | endoplasmic reticulum | golgi apparatus | lipid droplet | microtubule organizing center | cytosol | ribosome | cytoskeleton | plasma membrane | cilium | plastid | thylakoid | external encapsulating structure | extracellular matrix | cytoplasmic vesicle | organelle | other cellular component | |||
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Aspect | Term | |
---|---|---|
Cellular Component | extracellular region | |
Cellular Component | lysosome | |
Biological Process | adenylate cyclase-inhibiting G protein-coupled receptor signaling pathway | |
Biological Process | regulation of lipid metabolic process | |
Biological Process | sphingolipid metabolic process |
Keywords
- Biological process
Names & Taxonomy
Protein names
- Recommended nameProsaposin
- Alternative names
- Cleaved into 4 chains
Gene names
Organism names
- Organism
- Taxonomic lineageEukaryota > Metazoa > Chordata > Craniata > Vertebrata > Euteleostomi > Archelosauria > Archosauria > Dinosauria > Saurischia > Theropoda > Coelurosauria > Aves > Neognathae > Galloanserae > Galliformes > Phasianidae > Phasianinae > Gallus
Accessions
- Primary accessionO13035
Proteomes
Organism-specific databases
Phenotypes & Variants
Keywords
- Disease
PTM/Processing
Features
Showing features for signal, propeptide, chain, disulfide bond, glycosylation.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Signal | 1-17 | |||||
Sequence: MARRLLTLLGLLAAAVA | ||||||
Propeptide | PRO_0000031630 | 18-60 | ||||
Sequence: SPVLWQKDCAKGPEVWCQSLRTASQCGAVKHCQQNVWSKPAVN | ||||||
Chain | PRO_0000434973 | 18-518 | Prosaposin | |||
Sequence: SPVLWQKDCAKGPEVWCQSLRTASQCGAVKHCQQNVWSKPAVNSIPCDLCKELVTVVGKVLKDNGTEDEIRSYLEKRCEFLPDQGLASECKEIVDSYLPVIMDMIKEEFDKPEVVCSALSLCQSLQKHLAAMKLQKQLQSNKIPELDFSELTSPFMANVPLLLYPQDKPKQKSKATEDVCQDCIRLVTDVQEAVRTNATFVKSLVAHAKEECDRLGPGMSDMCKSYISEYSDLAIQMMMHMKDQQPKDICAMVGFCPSVKSVPLQTLVPAQVVHEVKMETVEKATVQEKTFSVCEICETMVKEVTGLLESNKTEEEIVHEMEVVCYLLPASVKDQCKDFIEVYGQALIDMLLEATNPEAVCVMLKCCAANKPPQQPVVVKPAGGFCDICKMIVAYADKELEKNATTTEIEALLEKVCHFLPESVSDQCVQFVEQYEPVVVQLLAEMMDPTFVCTKLGVCGAAKKPLLGEDACVWGPGYWCKNMETAAQCNAVDHCRRHVWN | ||||||
Chain | PRO_0000031631 | 61-143 | Saposin-A | |||
Sequence: SIPCDLCKELVTVVGKVLKDNGTEDEIRSYLEKRCEFLPDQGLASECKEIVDSYLPVIMDMIKEEFDKPEVVCSALSLCQSLQ | ||||||
Disulfide bond | 64↔139 | |||||
Sequence: CDLCKELVTVVGKVLKDNGTEDEIRSYLEKRCEFLPDQGLASECKEIVDSYLPVIMDMIKEEFDKPEVVCSALSLC | ||||||
Disulfide bond | 67↔133 | |||||
Sequence: CKELVTVVGKVLKDNGTEDEIRSYLEKRCEFLPDQGLASECKEIVDSYLPVIMDMIKEEFDKPEVVC | ||||||
Glycosylation | 81 | N-linked (GlcNAc...) asparagine | ||||
Sequence: N | ||||||
Disulfide bond | 95↔107 | |||||
Sequence: CEFLPDQGLASEC | ||||||
Propeptide | PRO_0000031632 | 144-193 | ||||
Sequence: KHLAAMKLQKQLQSNKIPELDFSELTSPFMANVPLLLYPQDKPKQKSKAT | ||||||
Chain | PRO_0000031633 | 194-276 | Saposin-B | |||
Sequence: EDVCQDCIRLVTDVQEAVRTNATFVKSLVAHAKEECDRLGPGMSDMCKSYISEYSDLAIQMMMHMKDQQPKDICAMVGFCPSV | ||||||
Disulfide bond | 197↔273 | |||||
Sequence: CQDCIRLVTDVQEAVRTNATFVKSLVAHAKEECDRLGPGMSDMCKSYISEYSDLAIQMMMHMKDQQPKDICAMVGFC | ||||||
Disulfide bond | 200↔267 | |||||
Sequence: CIRLVTDVQEAVRTNATFVKSLVAHAKEECDRLGPGMSDMCKSYISEYSDLAIQMMMHMKDQQPKDIC | ||||||
Glycosylation | 214 | N-linked (GlcNAc...) asparagine | ||||
Sequence: N | ||||||
Disulfide bond | 229↔240 | |||||
Sequence: CDRLGPGMSDMC | ||||||
Propeptide | PRO_0000031634 | 277-306 | ||||
Sequence: KSVPLQTLVPAQVVHEVKMETVEKATVQEK | ||||||
Chain | PRO_0000031635 | 307-387 | Saposin-C | |||
Sequence: TFSVCEICETMVKEVTGLLESNKTEEEIVHEMEVVCYLLPASVKDQCKDFIEVYGQALIDMLLEATNPEAVCVMLKCCAAN | ||||||
Disulfide bond | 311↔384 | |||||
Sequence: CEICETMVKEVTGLLESNKTEEEIVHEMEVVCYLLPASVKDQCKDFIEVYGQALIDMLLEATNPEAVCVMLKCC | ||||||
Disulfide bond | 314↔378 | |||||
Sequence: CETMVKEVTGLLESNKTEEEIVHEMEVVCYLLPASVKDQCKDFIEVYGQALIDMLLEATNPEAVC | ||||||
Glycosylation | 328 | N-linked (GlcNAc...) asparagine | ||||
Sequence: N | ||||||
Disulfide bond | 342↔353 | |||||
Sequence: CYLLPASVKDQC | ||||||
Propeptide | PRO_0000031636 | 388-398 | ||||
Sequence: KPPQQPVVVKP | ||||||
Chain | PRO_0000031637 | 399-479 | Saposin-D | |||
Sequence: AGGFCDICKMIVAYADKELEKNATTTEIEALLEKVCHFLPESVSDQCVQFVEQYEPVVVQLLAEMMDPTFVCTKLGVCGAA | ||||||
Disulfide bond | 403↔476 | |||||
Sequence: CDICKMIVAYADKELEKNATTTEIEALLEKVCHFLPESVSDQCVQFVEQYEPVVVQLLAEMMDPTFVCTKLGVC | ||||||
Disulfide bond | 406↔470 | |||||
Sequence: CKMIVAYADKELEKNATTTEIEALLEKVCHFLPESVSDQCVQFVEQYEPVVVQLLAEMMDPTFVC | ||||||
Glycosylation | 420 | N-linked (GlcNAc...) asparagine | ||||
Sequence: N | ||||||
Disulfide bond | 434↔445 | |||||
Sequence: CHFLPESVSDQC | ||||||
Propeptide | PRO_0000031638 | 480-518 | ||||
Sequence: KKPLLGEDACVWGPGYWCKNMETAAQCNAVDHCRRHVWN |
Post-translational modification
This precursor is proteolytically processed to 4 small peptides, which are similar to each other and are sphingolipid hydrolase activator proteins.
Keywords
- PTM
Proteomic databases
PTM databases
Interaction
Structure
Family & Domains
Features
Showing features for domain.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Domain | 19-59 | Saposin A-type 1 | ||||
Sequence: PVLWQKDCAKGPEVWCQSLRTASQCGAVKHCQQNVWSKPAV | ||||||
Domain | 60-143 | Saposin B-type 1 | ||||
Sequence: NSIPCDLCKELVTVVGKVLKDNGTEDEIRSYLEKRCEFLPDQGLASECKEIVDSYLPVIMDMIKEEFDKPEVVCSALSLCQSLQ | ||||||
Domain | 193-277 | Saposin B-type 2 | ||||
Sequence: TEDVCQDCIRLVTDVQEAVRTNATFVKSLVAHAKEECDRLGPGMSDMCKSYISEYSDLAIQMMMHMKDQQPKDICAMVGFCPSVK | ||||||
Domain | 307-388 | Saposin B-type 3 | ||||
Sequence: TFSVCEICETMVKEVTGLLESNKTEEEIVHEMEVVCYLLPASVKDQCKDFIEVYGQALIDMLLEATNPEAVCVMLKCCAANK | ||||||
Domain | 399-480 | Saposin B-type 4 | ||||
Sequence: AGGFCDICKMIVAYADKELEKNATTTEIEALLEKVCHFLPESVSDQCVQFVEQYEPVVVQLLAEMMDPTFVCTKLGVCGAAK | ||||||
Domain | 482-518 | Saposin A-type 2 | ||||
Sequence: PLLGEDACVWGPGYWCKNMETAAQCNAVDHCRRHVWN |
Keywords
- Domain
Phylogenomic databases
Family and domain databases
Sequence
- Sequence statusComplete
- Sequence processingThe displayed sequence is further processed into a mature form.
- Length518
- Mass (Da)57,601
- Last updated1997-07-01 v1
- ChecksumB803000E891C3963
Features
Showing features for sequence conflict.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Sequence conflict | 94 | in Ref. 2; AAF05899 | ||||
Sequence: R → T | ||||||
Sequence conflict | 486 | in Ref. 2; AAF05899 | ||||
Sequence: E → D |
Keywords
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
AB003471 EMBL· GenBank· DDBJ | BAA19914.1 EMBL· GenBank· DDBJ | mRNA | ||
AF108656 EMBL· GenBank· DDBJ | AAF05899.1 EMBL· GenBank· DDBJ | mRNA |