ID   SPTSA_RAT               Reviewed;          71 AA.
AC   Q4G019;
DT   10-JUL-2007, integrated into UniProtKB/Swiss-Prot.
DT   26-MAY-2009, sequence version 2.
DT   03-AUG-2022, entry version 87.
DE   RecName: Full=Serine palmitoyltransferase small subunit A {ECO:0000305};
DE   AltName: Full=Small subunit of serine palmitoyltransferase A;
DE            Short=ssSPTa;
GN   Name=Sptssa {ECO:0000312|RGD:1565821}; Synonyms=Ssspta;
OS   Rattus norvegicus (Rat).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia;
OC   Eutheria; Euarchontoglires; Glires; Rodentia; Myomorpha; Muroidea; Muridae;
OC   Murinae; Rattus.
OX   NCBI_TaxID=10116;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA].
RC   TISSUE=Spleen;
RX   PubMed=15489334; DOI=10.1101/gr.2596504;
RG   The MGC Project Team;
RT   "The status, quality, and expansion of the NIH full-length cDNA project:
RT   the Mammalian Gene Collection (MGC).";
RL   Genome Res. 14:2121-2127(2004).
CC   -!- FUNCTION: Stimulates the activity of serine palmitoyltransferase (SPT).
CC       The composition of the serine palmitoyltransferase (SPT) complex
CC       determines the substrate preference. The SPTLC1-SPTLC2-SPTSSA complex
CC       shows a strong preference for C16-CoA substrate, while the SPTLC1-
CC       SPTLC3-SPTSSA isozyme uses both C14-CoA and C16-CoA as substrates, with
CC       a slight preference for C14-CoA. Plays a role in MBOAT7 location to
CC       mitochondria-associated membranes (MAMs), may me involved in fatty acid
CC       remodeling phosphatidylinositol (PI). {ECO:0000250|UniProtKB:Q969W0}.
CC   -!- PATHWAY: Lipid metabolism; sphingolipid metabolism.
CC   -!- SUBUNIT: Interacts with SPTLC1; the interaction is direct. Component of
CC       the serine palmitoyltransferase (SPT) complex, composed of SPTLC1,
CC       either SPTLC2 or SPTLC3, and either SPTSSA or SPTSSB. Interacts with
CC       MBOAT7; the interaction facilitates MBOAT7 location to mitochondria-
CC       associated membranes (MAMs). {ECO:0000250|UniProtKB:Q969W0}.
CC   -!- SUBCELLULAR LOCATION: Endoplasmic reticulum membrane {ECO:0000305};
CC       Multi-pass membrane protein {ECO:0000305}.
CC   -!- SIMILARITY: Belongs to the SPTSS family. SPTSSA subfamily.
CC       {ECO:0000305}.
CC   -!- CAUTION: It is uncertain whether Met-1 or Met-4 is the initiator.
CC       {ECO:0000305}.
CC   -!- SEQUENCE CAUTION:
CC       Sequence=AAH98829.1; Type=Erroneous initiation; Note=Truncated N-terminus.; Evidence={ECO:0000305};
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DR   EMBL; BC098829; AAH98829.1; ALT_INIT; mRNA.
DR   RefSeq; NP_001041208.1; NM_001047743.1.
DR   AlphaFoldDB; Q4G019; -.
DR   SMR; Q4G019; -.
DR   STRING; 10116.ENSRNOP00000005825; -.
DR   PaxDb; Q4G019; -.
DR   Ensembl; ENSRNOT00000005825; ENSRNOP00000005825; ENSRNOG00000004292.
DR   GeneID; 500651; -.
DR   KEGG; rno:500651; -.
DR   UCSC; RGD:1565821; rat.
DR   CTD; 171546; -.
DR   RGD; 1565821; Sptssa.
DR   eggNOG; ENOG502S4Q3; Eukaryota.
DR   GeneTree; ENSGT00390000002766; -.
DR   HOGENOM; CLU_187811_1_0_1; -.
DR   InParanoid; Q4G019; -.
DR   OMA; AWKQISW; -.
DR   OrthoDB; 1627882at2759; -.
DR   PhylomeDB; Q4G019; -.
DR   TreeFam; TF328418; -.
DR   Reactome; R-RNO-1660661; Sphingolipid de novo biosynthesis.
DR   UniPathway; UPA00222; -.
DR   PRO; PR:Q4G019; -.
DR   Proteomes; UP000002494; Chromosome 6.
DR   Bgee; ENSRNOG00000004292; Expressed in thymus and 20 other tissues.
DR   Genevisible; Q4G019; RN.
DR   GO; GO:0005783; C:endoplasmic reticulum; ISS:UniProtKB.
DR   GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
DR   GO; GO:0017059; C:serine C-palmitoyltransferase complex; ISS:UniProtKB.
DR   GO; GO:0004758; F:serine C-palmitoyltransferase activity; ISO:RGD.
DR   GO; GO:0046513; P:ceramide biosynthetic process; ISO:RGD.
DR   GO; GO:0008104; P:protein localization; ISS:UniProtKB.
DR   GO; GO:0046512; P:sphingosine biosynthetic process; ISO:RGD.
DR   InterPro; IPR024512; Ser_palmitoyltrfase_ssu-like.
DR   Pfam; PF11779; SPT_ssu-like; 1.
PE   3: Inferred from homology;
KW   Endoplasmic reticulum; Lipid metabolism; Membrane; Reference proteome;
KW   Sphingolipid metabolism; Transmembrane; Transmembrane helix.
FT   CHAIN           1..71
FT                   /note="Serine palmitoyltransferase small subunit A"
FT                   /id="PRO_0000293704"
FT   TOPO_DOM        1..12
FT                   /note="Cytoplasmic"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        13..29
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TOPO_DOM        30..34
FT                   /note="Lumenal"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        35..57
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TOPO_DOM        58..71
FT                   /note="Cytoplasmic"
FT                   /evidence="ECO:0000255"
SQ   SEQUENCE   71 AA;  8452 MW;  ED4F189EB101703C CRC64;
     MAGMALARAW KQMSWFYYQY LLVTALYMLE PWERTVFNSM LVSVVGMALY TGYVFMPQHI
     MAILHYFEIV Q