ID   SAP_PIG                 Reviewed;          80 AA.
AC   P81405;
DT   15-DEC-1998, integrated into UniProtKB/Swiss-Prot.
DT   18-OCT-2001, sequence version 2.
DT   25-MAY-2022, entry version 114.
DE   RecName: Full=Saposin-B-Val;
DE   Contains:
DE     RecName: Full=Saposin-B;
DE     AltName: Full=Cerebroside sulfate activator;
DE              Short=CS-ACT;
DE     AltName: Full=Non-specific activator;
DE     AltName: Full=Sphingolipid activator protein 1;
DE              Short=SAP-1;
GN   Name=PSAP;
OS   Sus scrofa (Pig).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia;
OC   Eutheria; Laurasiatheria; Artiodactyla; Suina; Suidae; Sus.
OX   NCBI_TaxID=9823;
RN   [1]
RP   PROTEIN SEQUENCE OF 1-79, AND DISULFIDE BONDS IN SAPOSIN-B.
RC   TISSUE=Kidney;
RX   PubMed=8471613; DOI=10.1021/bi00066a028;
RA   Stevens R.L., Faull K.F., Conklin K.A., Green B.N., Fluharty A.L.;
RT   "Porcine cerebroside sulfate activator: further structural characterization
RT   and disulfide identification.";
RL   Biochemistry 32:4051-4059(1993).
RN   [2]
RP   PROTEIN SEQUENCE OF 1-64.
RC   TISSUE=Kidney;
RX   PubMed=1562358; DOI=10.1016/0885-4505(92)90009-n;
RA   Fluharty A.L., Katona Z., Meek W.E., Frei K., Fowler A.V.;
RT   "The cerebroside sulfate activator from pig kidney: purification and
RT   molecular structure.";
RL   Biochem. Med. Metab. Biol. 47:66-85(1992).
RN   [3]
RP   IDENTIFICATION BY MASS SPECTROMETRY.
RC   TISSUE=Kidney;
RX   PubMed=10510427;
RX   DOI=10.1002/(sici)1096-9888(199910)34:10<1040::aid-jms863>3.0.co;2-x;
RA   Faull K.F., Whitelegge J.P., Higginson J., To T., Johnson J.,
RA   Krutchinsky A.N., Standing K.G., Waring A.J., Stevens R.L., Fluharty C.B.,
RA   Fluharty A.L.;
RT   "Cerebroside sulfate activator protein (Saposin B): chromatographic and
RT   electrospray mass spectrometric properties.";
RL   J. Mass Spectrom. 34:1040-1054(1999).
RN   [4]
RP   GLYCOSYLATION AT ASN-21, AND STRUCTURE OF CARBOHYDRATE ON ASN-21.
RX   PubMed=11180632;
RX   DOI=10.1002/1096-9888(200012)35:12<1416::aid-jms75>3.0.co;2-k;
RA   Faull K.F., Johnson J., Kim M.J., To T., Whitelegge J.P., Stevens R.L.,
RA   Fluharty C.B., Fluharty A.L.;
RT   "Structure of the asparagine-linked sugar chains of porcine kidney and
RT   human urine cerebroside sulfate activator protein.";
RL   J. Mass Spectrom. 35:1416-1424(2000).
CC   -!- FUNCTION: Saposin-B stimulates the hydrolysis of galacto-cerebroside
CC       sulfate by arylsulfatase A (EC 3.1.6.8), GM1 gangliosides by beta-
CC       galactosidase (EC 3.2.1.23) and globotriaosylceramide by alpha-
CC       galactosidase A (EC 3.2.1.22). Saposin-B forms a solubilizing complex
CC       with the substrates of the sphingolipid hydrolases.
CC   -!- SUBUNIT: Saposin-B is a homodimer. Interacts with GRN; facilitates
CC       lysosomal delivery of progranulin from the extracellular space and the
CC       biosynthetic pathway (By similarity). {ECO:0000250,
CC       ECO:0000250|UniProtKB:P07602}.
CC   -!- PTM: The one residue extended Saposin-B-Val is only found in a minority
CC       of the chains.
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DR   PIR; A49475; A49475.
DR   AlphaFoldDB; P81405; -.
DR   SMR; P81405; -.
DR   STRING; 9823.ENSSSCP00000026917; -.
DR   GlyConnect; 547; 1 N-Linked glycan (1 site).
DR   PeptideAtlas; P81405; -.
DR   eggNOG; KOG1340; Eukaryota.
DR   HOGENOM; CLU_033757_0_0_1; -.
DR   Proteomes; UP000008227; Unplaced.
DR   Proteomes; UP000314985; Unplaced.
DR   Genevisible; P81405; SS.
DR   GO; GO:0005576; C:extracellular region; ISS:UniProtKB.
DR   GO; GO:0005770; C:late endosome; ISS:UniProtKB.
DR   GO; GO:0005764; C:lysosome; ISS:UniProtKB.
DR   GO; GO:0007041; P:lysosomal transport; ISS:UniProtKB.
DR   GO; GO:0006665; P:sphingolipid metabolic process; IEA:UniProtKB-KW.
DR   InterPro; IPR007856; SapB_1.
DR   InterPro; IPR008138; SapB_2.
DR   InterPro; IPR008373; Saposin.
DR   InterPro; IPR011001; Saposin-like.
DR   InterPro; IPR008139; SaposinB_dom.
DR   Pfam; PF05184; SapB_1; 1.
DR   Pfam; PF03489; SapB_2; 1.
DR   PRINTS; PR01797; SAPOSIN.
DR   SMART; SM00741; SapB; 1.
DR   SUPFAM; SSF47862; SSF47862; 1.
DR   PROSITE; PS50015; SAP_B; 1.
PE   1: Evidence at protein level;
KW   Direct protein sequencing; Disulfide bond; Glycoprotein; Lipid metabolism;
KW   Reference proteome; Sphingolipid metabolism.
FT   CHAIN           1..80
FT                   /note="Saposin-B-Val"
FT                   /evidence="ECO:0000269|PubMed:8471613"
FT                   /id="PRO_0000031627"
FT   CHAIN           1..79
FT                   /note="Saposin-B"
FT                   /evidence="ECO:0000269|PubMed:8471613"
FT                   /id="PRO_0000031628"
FT   DOMAIN          1..80
FT                   /note="Saposin B-type"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00415"
FT   CARBOHYD        21
FT                   /note="N-linked (GlcNAc...) (complex) asparagine"
FT                   /evidence="ECO:0000269|PubMed:11180632"
FT                   /id="CAR_000177"
FT   DISULFID        4..77
FT                   /evidence="ECO:0000269|PubMed:8471613"
FT   DISULFID        7..71
FT                   /evidence="ECO:0000269|PubMed:8471613"
FT   DISULFID        36..47
FT                   /evidence="ECO:0000269|PubMed:8471613"
SQ   SEQUENCE   80 AA;  8949 MW;  EF7BA249B63E789C CRC64;
     GDVCQDCIQM VTDLQNAVRT NSTFVEALVN HAKEECDRLG PGMADMCKNY ISQYSEIAIQ
     MMMHMQPKDI CGLVGFCEEV