Seroatlas · Human Serome Atlas

SLC5A3

Sodium/myo-inositol cotransporter

Also known as: SC5A3_HUMAN, SMIT, SMIT1

Cross-references: UniProt · Ensembl · Human Protein Atlas · GeneCards · NCBI Gene

Protein identityUniProt · HPA

UniProt accession
P53794
Gene
SLC5A3
Ensembl
ENSG00000198743
Chromosome
21
Canonical length
718 aa
Protein class
Metabolic proteins, Predicted membrane proteins, Transporters
Subcellular location
Plasma membrane

OverviewNCBI Gene

Enables myo-inositol:sodium symporter activity; potassium channel regulator activity; and transmembrane transporter binding activity. Predicted to be involved in several processes, including inositol metabolic process; monosaccharide transmembrane transport; and myo-inositol import across plasma membrane. Predicted to act upstream of or within several processes, including positive regulation of protein localization to membrane; positive regulation of reactive oxygen species biosynthetic process; and regulation of respiratory gaseous exchange. Located in perinuclear region of cytoplasm and plasma membrane. [provided by Alliance of Genome Resources, Jul 2025]

Canonical amino-acid sequenceUniProt

718 residues, UniProt reviewed canonical sequence.

>P53794|SLC5A3
     1  MRAVLDTADI AIVALYFILV MCIGFFAMWK SNRSTVSGYF LAGRSMTWVA IGASLFVSNI
    61  GSEHFIGLAG SGAASGFAVG AWEFNALLLL QLLGWVFIPI YIRSGVYTMP EYLSKRFGGH
   121  RIQVYFAALS LILYIFTKLS VDLYSGALFI QESLGWNLYV SVILLIGMTA LLTVTGGLVA
   181  VIYTDTLQAL LMIIGALTLM IISIMEIGGF EEVKRRYMLA SPDVTSILLT YNLSNTNSCN
   241  VSPKKEALKM LRNPTDEDVP WPGFILGQTP ASVWYWCADQ VIVQRVLAAK NIAHAKGSTL
   301  MAGFLKLLPM FIIVVPGMIS RILFTDDIAC INPEHCMLVC GSRAGCSNIA YPRLVMKLVP
   361  VGLRGLMMAV MIAALMSDLD SIFNSASTIF TLDVYKLIRK SASSRELMIV GRIFVAFMVV
   421  ISIAWVPIIV EMQGGQMYLY IQEVADYLTP PVAALFLLAI FWKRCNEQGA FYGGMAGFVL
   481  GAVRLILAFA YRAPECDQPD NRPGFIKDIH YMYVATGLFW VTGLITVIVS LLTPPPTKEQ
   541  IRTTTFWSKK NLVVKENCSP KEEPYKMQEK SILRCSENNE TINHIIPNGK SEDSIKGLQP
   601  EDVNLLVTCR EEGNPVASLG HSEAETPVDA YSNGQAALMG EKERKKETDD GGRYWKFIDW
   661  FCGFKSKSLS KRSLRDLMEE EAVCLQMLEE TRQVKVILNI GLFAVCSLGI FMFVYFSL

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against SLC5A3 can act on the native protein depends on physical access: surface and secreted proteins are reachable by circulating antibodies, intracellular proteins usually are not.

Antibody reachability
Cell surface
Secreted
No
Transmembrane segments
12
Mean surface accessibility (rSASA)
0.28
Highest tissue expression
27 nTPM

Expression across tissuesHPA

Tissue

  • kidney: 27 nTPM
  • thyroid gland: 24 nTPM
  • choroid plexus: 21 nTPM
  • blood vessel: 13 nTPM
  • placenta: 9.9 nTPM
  • adipose tissue: 6.7 nTPM

Single-cell type

  • pituicytes/fscs: 5.2 nCPM
  • endometrial stromal cells: 4.8 nCPM
  • epididymal efferent duct absorptive cells: 4.4 nCPM
  • epididymal principal cells: 4.2 nCPM
  • erythrocyte progenitors: 4.2 nCPM
  • basal prostatic cells: 3.9 nCPM

Immune cell

  • gdT-cell: 0.6 nTPM
  • naive CD8 T-cell: 0.6 nTPM
  • MAIT T-cell: 0.5 nTPM
  • plasmacytoid DC: 0.5 nTPM
  • memory CD8 T-cell: 0.4 nTPM
  • naive CD4 T-cell: 0.4 nTPM

Brain region

  • choroid plexus: 208 nTPM
  • hypothalamus: 47 nTPM
  • hippocampal formation: 27 nTPM
  • midbrain: 25 nTPM
  • medulla oblongata: 25 nTPM
  • pons: 24 nTPM

Genetic constraint and essentialitygnomAD · DepMap

Does the body need this protein intact? Low LOEUF or a strong DepMap dependency means loss or blockade of the protein is likely to be felt.

gnomAD LOEUF (loss-of-function intolerance)
0.32
gnomAD pLI
0.97
gnomAD missense Z
2.76
DepMap mean gene effect
-0.16
DepMap dependency class
selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 4% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Biological processes

Molecular functions

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

InteractionsUniProt · HPA

Protein binding partners of SLC5A3 in the human serome: UniProt-annotated complex subunits plus reported interactors. Each links to its own Seroatlas record.

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads SLC5A3 as an antibody target. Whether an autoantibody or antibody against SLC5A3 could matter depends on whether native SLC5A3 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

SLC5A3 is annotated at the cell surface, where native SLC5A3 is exposed to circulating antibodies and is a prime autoantibody target that could block, deplete, or overstimulate it.

Annotation status

The present source text does not explicitly label SLC5A3 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/SLC5A3. Study-independent annotations aggregated from UniProt, Human Protein Atlas, PubMed, IEDB, Pfam, InterPro, Gene Ontology, AlphaFold, gnomAD, DepMap, ClinVar, TCGA. Catalog release seroatlas-reviewed-human-uniprot-20260313.

Seroatlas is the reference for exploring autoantibody and antibody serology at the human-protein level: the autoreactome and human serome, multiplex serology (HuProt, HuScan, VirScan, PhIP-Seq).

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