Seroatlas · Human Serome Atlas

PSD4

PH and SEC7 domain-containing protein 4

Also known as: EFA6B, PSD4_HUMAN, TIC

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

Protein identityUniProt · HPA

UniProt accession: Q8NDX1
Gene: PSD4
Ensembl: ENSG00000125637
Chromosome: 2
Canonical length: 1056 aa
Protein class: Predicted intracellular proteins

OverviewNCBI Gene

Predicted to enable guanyl-nucleotide exchange factor activity and phospholipid binding activity. Predicted to be involved in regulation of ARF protein signal transduction. Located in ruffle membrane. [provided by Alliance of Genome Resources, Jul 2025]

Canonical amino-acid sequenceUniProt

1056 residues, UniProt reviewed canonical sequence.

>Q8NDX1|PSD4
     1  MMGDYRLPDH PQPMEILNLY LGDSLEPHPG ECPRETCSHE DPPEPFEEQT WATDPPEPTR
    61  QNVPPWGSGV ELTHLGSWVH QDGLEPCQEQ TRATDPPEST RQDAPPWGSG VELTHLGSPS
   121  AQREHRQNTA SPGSPVNSHL PGSPKQNRST STQVVFWAGI LQAQMCVLDL EEELEKTEGL
   181  KAGLKCCLPT PPVDLPGDTG LHSSPPENED SGEDSSEPEG EGQAWLREGT PDSSPQWGAE
   241  EESMFFSNPL FLASPCSENS ASGECFSWGA SDSHAGVRTG PESPATLEPP LPEDTVLWEL
   301  ESEPDLGDGA AISGHCTPPF PVPIYKPHSI CWASVAAAEG APAAPPGHGE SEGDRLGPAP
   361  SAAPCVDEAL TWESGCVGSD LGPAAHPVQP WASLSPEGWQ RGGPFWPQVT LNSQDRDERE
   421  GGHPQESLPC TLAPCPWRSP ASSPEPSSPE SESRGPGPRP SPASSQEGSP QLQHHSSGIL
   481  PKWTLDASQS SLLETDGEQP SSLKKKEAGE APKPGEEVKS EGTARPAETG DVQPDIHLTS
   541  AEHENLRTPM NSSWLPGSPM PQAQSPEEGQ RPPAGDKLAN GVRNNKVAWN LASRLYRLEG
   601  FRKSEVAAYL QKNNDFSRAV AEEYLSFFQF GGQSLDRALR SFLQALVLSG ETQERERILY
   661  QFSRRFHHCN PGIFPSVDSV HTLTCAIMLL NTDLHGQNIG KSMSCQEFIT NLNGLRDGGN
   721  FPKELLKALY WSIRSEKLEW AVDEEDTARP EKAQPSLPAG KMSKPFLQLA QDPTVPTYKQ
   781  GILARKMHQD ADGKKTPWGK RGWKMFHTLL RGMVLYFLKQ GEDHCLEGES LVGQMVDEPV
   841  GVHHSLATPA THYTKKPHVF QLRTADWRLY LFQAPTAKEM SSWIARINLA AATHSAPPFP
   901  AAVGSQRRFV RPILPVGPAQ SSLEEQHRSH ENCLDAAADD LLDLQRNLPE RRGRGRELEE
   961  HRLRKEYLEY EKTRYETYVQ LLVARLHCPS DALDLWEEQL GREAGGTREP KLSLKKSHSS
  1021  PSLHQDEAPT TAKVKRNISE RRTYRKIIPK RNRNQL

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against PSD4 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: 0
Mean surface accessibility (rSASA): 0.55
Highest tissue expression: 9.4 nTPM

Expression across tissuesHPA

Tissue

liver: 9.4 nTPM
small intestine: 6.4 nTPM
spleen: 6.3 nTPM
pancreas: 5.8 nTPM
salivary gland: 5.6 nTPM
thymus: 5.5 nTPM

Single-cell type

neutrophils: 83 nCPM
hepatocytes: 75 nCPM
prostatic glandular cells: 66 nCPM
endometrial luminal cells: 63 nCPM
enterocytes: 62 nCPM
esophageal apical cells: 52 nCPM

Immune cell

neutrophil: 3.9 nTPM
NK-cell: 2.4 nTPM
gdT-cell: 2 nTPM
naive CD8 T-cell: 1.9 nTPM
memory CD8 T-cell: 1.8 nTPM
eosinophil: 1.7 nTPM

Brain region

hypothalamus: 4.4 nTPM
amygdala: 4.1 nTPM
cerebral cortex: 3.8 nTPM
pons: 3.6 nTPM
hippocampal formation: 3.4 nTPM
medulla oblongata: 3.3 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): 0.37
gnomAD pLI: 0.42
gnomAD missense Z: 0.96
DepMap mean gene effect: -0.1
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

regulation of ARF protein signal transduction

Molecular functions

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads PSD4 as an antibody target. Whether an autoantibody or antibody against PSD4 could matter depends on whether native PSD4 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

PSD4 is annotated at the cell surface, where native PSD4 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 PSD4 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

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