PSAP
entrez
5660
canonical
uniprot
P07602
canonical
ensembl
ENSG00000197746
resolver
ensp
ENSP00000378394
resolver
genesymbol
PSAP
resolver
genesymbol_syn
GLBA
resolver
genesymbol_syn
SAP1
resolver
hgnc
HGNC:9498
resolver
uniprot
P07292
resolver
uniprot
P15793
resolver
uniprot
P78538
resolver
uniprot
P78541
resolver
uniprot
P78546
resolver
uniprot
P78547
resolver
uniprot
P78558
resolver
uniprot
Q53Y86
resolver
uniprot
Q6IBQ6
resolver
uniprot
Q92739
resolver
uniprot
Q92740
resolver
uniprot
Q92741
resolver
uniprot
Q92742
resolver
uniprot_entry
SAP_HUMAN
resolver
uniprot_sec
P07292
resolver
uniprot_sec
P15793
resolver
uniprot_sec
P78538
resolver
uniprot_sec
P78541
resolver
uniprot_sec
P78546
resolver
uniprot_sec
P78547
resolver
uniprot_sec
P78558
resolver
uniprot_sec
Q53Y86
resolver
uniprot_sec
Q6IBQ6
resolver
uniprot_sec
Q92739
resolver
uniprot_sec
Q92740
resolver
uniprot_sec
Q92741
resolver
uniprot_sec
Q92742
resolver
amino_acid_sequence
MYALFLLASLLGAALAGPVLGLKECTRGSAVWCQNVKTASDCGAVKHCLQTVWNKPTVKSLPCDICKDVVTAAGDMLKDNATEEEILVYLEKTCDWLPKPNMSASCKEIVDSYLPVILDIIKGEMSRPGEVCSALNLCESLQKHLAELNHQKQLESNKIPELDMTEVVAPFMANIPLLLYPQDGPRSKPQPKDNGDVCQDCIQMVTDIQTAVRTNSTFVQALVEHVKEECDRLGPGMADICKNYISQYSEIAIQMMMHMQPKEICALVGFCDEVKEMPMQTLVPAKVASKNVIPALELVEPIKKHEVPAKSDVYCEVCEFLVKEVTKLIDNNKTEKEILDAFDKMCSKLPKSLSEECQEVVDTYGSSILSILLEEVSPELVCSMLHLCSGTRLPALTVHVTQPKDGGFCEVCKKLVGYLDRNLEKNSTKQEILAALEKGCSFLPDPYQKQCDQFVAEYEPVLIEILVEVMDPSFVCLKIGACPSAHKPLLGTEKCIWGPSYWCQNTETAAQCNAVEHCKRHVWN
uniprot
proteins
disease_involvement
DISEASE: Combined saposin deficiency (PSAPD) [MIM:611721]: An autosomal recessive storage disorder characterized by hepatosplenomegaly and severe neurologic disease, due to absence of all saposins. PSAPD has a fatal outcome in infancy. {ECO:0000269|PubMed:11309366, ECO:0000269|PubMed:1371116}. Note=The disease is caused by variants affecting the gene represented in this entry.; DISEASE: Metachromatic leukodystrophy due to saposin B deficiency (MLDSAPB) [MIM:249900]: A form of metachromatic leukodystrophy biochemically characterized by tissue accumulation of cerebroside-3-sulfate, saposin B deficiency, and normal arylsulfatase A activity. Clinical manifestations include periventricular white matter abnormalities, demyelination, and peripheral neuropathy. Additional neurological features include dysarthria, ataxic gait, psychomotor regression, seizures, cognitive decline and spastic quadriparesis. {ECO:0000269|PubMed:10196694, ECO:0000269|PubMed:10682309, ECO:0000269|PubMed:2019586, ECO:0000269|PubMed:2302219, ECO:0000269|PubMed:2320574}. Note=The disease is caused by variants affecting the gene represented in this entry.; DISEASE: Gaucher disease, atypical, due to saposin C deficiency (GDSAPC) [MIM:610539]: A disease characterized by marked glucosylceramide accumulation in the spleen without having a deficiency of glucosylceramide-beta glucosidase characteristic of classic Gaucher disease. Gaucher disease is a lysosomal storage disorder characterized by skeletal deterioration, hepatosplenomegaly, and organ dysfunction. There are several subtypes based on the presence and severity of neurological involvement. {ECO:0000269|PubMed:17919309, ECO:0000269|PubMed:2060627}. Note=The disease is caused by variants affecting the gene represented in this entry.; DISEASE: Krabbe disease, atypical, due to saposin A deficiency (KRBSAPA) [MIM:611722]: An autosomal recessive disorder of galactosylceramide metabolism. Clinical features include neurologic regression around age 3 months, loss of spontaneous movements, hyporeflexia, generalized brain atrophy, and diffuse white matter dysmyelination. {ECO:0000269|PubMed:15773042, ECO:0000269|PubMed:16905746}. Note=The disease is caused by variants affecting the gene represented in this entry.; DISEASE: Note=Defects in PSAP saposin-D region are found in a variant of Tay-Sachs disease (GM2-gangliosidosis).; DISEASE: Parkinson disease 24, autosomal dominant (PARK24) [MIM:619491]: An autosomal dominant form of Parkinson disease, a complex neurodegenerative disorder characterized by bradykinesia, resting tremor, muscular rigidity and postural instability, as well as by a clinically significant response to treatment with levodopa. The pathology involves the loss of dopaminergic neurons in the substantia nigra and the presence of Lewy bodies (intraneuronal accumulations of aggregated proteins), in surviving neurons in various areas of the brain. PARK24 shows incomplete penetrance. {ECO:0000269|PubMed:32201884}. Note=Disease susceptibility is associated with variants affecting the gene represented in this entry.
uniprot
proteins
function
FUNCTION: Saposins are specific low-molecular mass non-enzymatic glycoproteins that act as activator proteins for lysosomal sphingolipid-degrading enzymes, facilitating the hydrolysis of sphingolipids by extracting lipid substrates from membranes and presenting them to their respective enzymes. They are derived from a common precursor protein, prosaposin, which is proteolytically cleaved to yield four homologous proteins (saposin A, B, C, and D), each with distinct but partially overlapping lipid and enzyme specificities. {ECO:0000269|PubMed:16905746}.; 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: [Saposin-A]: Acts as an essential lysosomal cofactor that activates galactocerebrosidase (GALC, EC 3.2.1.46) by facilitating enzyme access to its membrane-embedded galactosylceramide substrate, the principal lipid component of myelin. {ECO:0000269|PubMed:16905746}.; FUNCTION: [Saposin-B]: Stimulates the hydrolysis of galacto-cerebroside sulfate by arylsulfatase A ARSA (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). Forms a solubilizing complex with the substrates of the sphingolipid hydrolases. {ECO:0000269|PubMed:19224915}.; FUNCTION: [Saposin-C]: Acts as an essential lysosomal cofactor that activates acid beta-glucosylceramidases (EC 3.2.1.45) by altering lipid bilayer properties to facilitate enzyme access to its membrane-embedded glucosylceramide substrate, while also protecting glucocerebrosidase from intralysosomal proteolytic degradation. {ECO:0000269|PubMed:12813057, ECO:0000269|PubMed:8262201}.; FUNCTION: [Saposin-D]: Acts as a lysosomal activator protein that stimulates acid ceramidase (EC 3.5.1.23) by solubilizing and presenting ceramide substrates at the lipid-water interface, facilitating their hydrolysis into sphingosine and fatty acids. It also activates acid sphingomyelinase (EC 3.1.4.12), though ceramide catabolism represents its primary physiological role. {ECO:0000269|PubMed:2845979, ECO:0000269|PubMed:8185598, ECO:0000269|PubMed:8203897}.
uniprot
proteins
mass_dalton
58113
uniprot
proteins
mutagenesis
MUTAGEN 106; /note="C->F: Unable to mobilize lipids out of the membrane."; /evidence="ECO:0000269|PubMed:16905746"; MUTAGEN 132; /note="C->F,A: Unable to mobilize lipids out of the membrane."; /evidence="ECO:0000269|PubMed:16905746"; MUTAGEN 240; /note="I->C: Strongly decreases stimulation of cerebroside sulfate hydrolysis."; /evidence="ECO:0000269|PubMed:12518053
uniprot
proteins
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.
uniprot
proteins
pubmed
10196694
uniprot
proteins
pubmed
10383054
uniprot
proteins
pubmed
10406958
uniprot
proteins
pubmed
10510427
uniprot
proteins
pubmed
10562467
uniprot
proteins
pubmed
10682309
uniprot
proteins
pubmed
11180632
uniprot
proteins
pubmed
11309366
uniprot
proteins
pubmed
12510003
uniprot
proteins
pubmed
12518053
uniprot
proteins
pubmed
12813057
uniprot
proteins
pubmed
1371116
uniprot
proteins
pubmed
14657016
uniprot
proteins
pubmed
15164054
uniprot
proteins
pubmed
15489334
uniprot
proteins
pubmed
15773042
uniprot
proteins
pubmed
1612590
uniprot
proteins
pubmed
16905746
uniprot
proteins
pubmed
17919309
uniprot
proteins
pubmed
19159218
uniprot
proteins
pubmed
19167329
uniprot
proteins
pubmed
19224915
uniprot
proteins
pubmed
1958198
uniprot
proteins
pubmed
2013321
uniprot
proteins
pubmed
2019586
uniprot
proteins
pubmed
2060627
uniprot
proteins
pubmed
21269460
uniprot
proteins
pubmed
21835174
uniprot
proteins
pubmed
2209618
uniprot
proteins
pubmed
22431521
uniprot
proteins
pubmed
2302219
uniprot
proteins
pubmed
2320574
uniprot
proteins
pubmed
24275569
uniprot
proteins
pubmed
2498298
uniprot
proteins
pubmed
2515150
uniprot
proteins
pubmed
25944712
uniprot
proteins
pubmed
26370502
uniprot
proteins
pubmed
2717620
uniprot
proteins
pubmed
2825202
uniprot
proteins
pubmed
2842863
uniprot
proteins
pubmed
2845979
uniprot
proteins
pubmed
2868718
uniprot
proteins
pubmed
3048308
uniprot
proteins
pubmed
32201884
uniprot
proteins
pubmed
3242555
uniprot
proteins
pubmed
3442600
uniprot
proteins
pubmed
7730378
uniprot
proteins
pubmed
7866401
uniprot
proteins
pubmed
8185598
uniprot
proteins
pubmed
8203897
uniprot
proteins
pubmed
8262201
uniprot
proteins
pubmed
8323276
uniprot
proteins
pubmed
8370464
uniprot
proteins
sequence_length
524
uniprot
proteins
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}.
uniprot
proteins