Seroatlas · Human Serome Atlas

SLC45A4

Solute carrier family 45 member 4

Also known as: KIAA1126, S45A4_HUMAN

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

Protein identityUniProt · HPA

UniProt accession: Q5BKX6
Gene: SLC45A4
Ensembl: ENSG00000022567
Chromosome: 8
Canonical length: 768 aa
Protein class: Predicted membrane proteins, Transporters
Subcellular location: Plasma membrane

OverviewNCBI Gene

Predicted to enable sucrose:proton symporter activity. Predicted to be involved in sucrose transport. Predicted to be active in membrane. [provided by Alliance of Genome Resources, Jul 2025]

Canonical amino-acid sequenceUniProt

768 residues, UniProt reviewed canonical sequence.

>Q5BKX6|SLC45A4
     1  MKMAPQNADP ESMQVQELSV PLPDPQKAGG AEAENCETIS EGSIDRIPMR LWVMHGAVMF
    61  GREFCYAMET ALVTPILLQI GLPEQYYSLT WFLSPILGLI FTPLIGSASD RCTLSWGRRR
   121  PFILALCVGV LFGVALFLNG SAIGLALGDV PNRQPIGIVL TVLGVVVLDF SADATEGPIR
   181  AYLLDVVDSE EQDMALNIHA FSAGLGGAIG YVLGGLDWTQ TFLGSWFRTQ NQVLFFFAAI
   241  IFTVSVALHL FSIDEEQYSP QQERSAEEPG ALDGGEPHGV PAFPDEVQSE HELALDYPDV
   301  DIMRSKSDSA LHVPDTALDL EPELLFLHDI EPSIFHDASY PATPRSTSQE LAKTKLPRLA
   361  TFLKEAAKED ETLLDNHLNE AKVPNGSGSP TKDALGGYTR VDTKPSATSS SMRRRRHAFR
   421  RQASSTFSYY GKLGSHCYRY RRANAVVLIK PSRSMSDLYD MQKRQRQHRH RNQSGATTSS
   481  GDTESEEGEG ETTVRLLWLS MLKMPRELMR LCLCHLLTWF SVIAEAVFYT DFMGQVIFEG
   541  DPKAPSNSTA WQAYNAGVKM GCWGLVIYAA TGAICSALLQ KYLDNYDLSV RVIYVLGTLG
   601  FSVGTAVMAM FPNVYVAMVT ISTMGIVSMS ISYCPYALLG QYHDIKQYIH HSPGNSKRGF
   661  GIDCAILSCQ VYISQILVAS ALGGVVDAVG TVRVIPMVAS VGSFLGFLTA TFLVIYPNVS
   721  EEAKEEQKGL SSPLAGEGRA GGNSEKPTVL KLTRKEGLQG PVETESVV

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against SLC45A4 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): 0.43
Highest tissue expression: 13 nTPM

Expression across tissuesHPA

Tissue

pituitary gland: 13 nTPM
stomach: 12 nTPM
cerebral cortex: 12 nTPM
testis: 12 nTPM
kidney: 9.7 nTPM
salivary gland: 7.3 nTPM

Single-cell type

neutrophils: 831 nCPM
somatotrophs: 430 nCPM
endometrial glandular cells: 394 nCPM
renal collecting duct principal cells: 371 nCPM
endometrial luminal cells: 369 nCPM
cone photoreceptor cells: 188 nCPM

Immune cell

eosinophil: 8.3 nTPM
neutrophil: 7 nTPM
basophil: 1.1 nTPM
memory CD8 T-cell: 0.3 nTPM
plasmacytoid DC: 0.3 nTPM
T-reg: 0.2 nTPM

Brain region

cerebral cortex: 50 nTPM
choroid plexus: 47 nTPM
pons: 29 nTPM
white matter: 28 nTPM
hippocampal formation: 26 nTPM
basal ganglia: 23 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): 0.71
gnomAD pLI: 0
gnomAD missense Z: 0.83
DepMap mean gene effect: 0.1
DepMap dependency class: none

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 8% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Biological processes

Molecular functions

polyamine transmembrane transporter activity
putrescine transmembrane transporter activity
spermidine transmembrane transporter activity
sucrose:proton symporter activity
spermine transmembrane transporter activity

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads SLC45A4 as an antibody target. Whether an autoantibody or antibody against SLC45A4 could matter depends on whether native SLC45A4 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

SLC45A4 is annotated at the cell surface, where native SLC45A4 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 SLC45A4 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

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