Seroatlas · Human Serome Atlas

PPP4R4

Serine/threonine-protein phosphatase 4 regulatory subunit 4

Also known as: CFAP14, KIAA1622, PP4R4, PP4R4_HUMAN

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

Protein identityUniProt · HPA

UniProt accession
Q6NUP7
Gene
PPP4R4
Ensembl
ENSG00000119698
Chromosome
14
Canonical length
873 aa
Protein class
Predicted intracellular proteins
Subcellular location
Primary cilium,Basal body,Cytosol

OverviewNCBI Gene

The protein encoded by this gene is a HEAT-like repeat-containing protein. The HEAT repeat is a tandemly repeated, 37-47 amino acid long module occurring in a number of cytoplasmic proteins. Arrays of HEAT repeats form a rod-like helical structure and appear to function as protein-protein interaction surfaces. The repeat-containing region of this protein has some similarity to the constant regulatory domain of the protein phosphatase 2A PR65/A subunit. The encoded protein binds protein serine/threonine phosphatase 4c in the cytoplasm. [provided by RefSeq, Jan 2017]

Canonical amino-acid sequenceUniProt

873 residues, UniProt reviewed canonical sequence.

>Q6NUP7|PPP4R4
     1  MHPPPPAAAM DFSQNSLFGY MEDLQELTII ERPVRRSLKT PEEIERLTVD EDLSDIERAV
    61  YLLSAGQDVQ GTSVIANLPF LMRQNPTETL RRVLPKVREA LHVAGVEMQL TAAMSFLTIL
   121  QDESVSIHAY THSFLQVILL HLEHRDTGVS NAWLETLLSV IEVLPKETLR HEILNPLVSK
   181  AQLSQTVQSR LVSCKILGKL TNKFDAHTIK REILPLVKSL CQDVEYEVRS CMCRQLENIA
   241  QGIGTELTKS VVLPELIELS RDEGSSVRLA AFETLVNLLD IFDTDDRSQT ILPLVKSFCE
   301  KSFKADESIL ISLSFHLGKL CHGLYGIFTP DQHLRFLEFY KKLCTLGLQQ ENGHNENQIP
   361  PQILEQEKKY ISVRKNCAYN FPAMIVFVDP KNFHMELYST FFCLCHDPEV PVRYTIAICF
   421  YEVSKLLNSG VYLIHKELIT LLQDESLEVL DALIDHLPEI LELMSTGGES SVQENKLSSL
   481  PDLIPALTAA EQRAAASLKW RTHEKLLQKY ACLPHVISSD QIYYRFLQRM FTIMMTNNVL
   541  PVQKAASRTL CIFLRYNRKQ EQRHEVIQKL IEQLGQGKSY WNRLRFLDTC EFIIEIFSKS
   601  FFCKYFFLPA IELTHDPVAN VRMKLCYLLP KVKSTLKIPA DKHLLQQLEM CVRKLLCQEK
   661  DKDVLAIVKR TVLELDRMEM SMDAFQKKFY EKDLLDQEKE REELLLLEME QLEKEKQQND
   721  GRPMSDKMFE KKRRDTKTPT QSLPKNIPIS VPGPSSVTPS TSKEIKKSKL IRSQSFNNQA
   781  FHAKYGNLEK CASKSSTTGY TTSVSGLGKT SVLSLADDSF RTRNASSVPS SFSPNTPLPS
   841  TSRGTGNSVD PKSSGSKDTQ PRKATLKSRK SNP

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against PPP4R4 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
Intracellular
Secreted
No
Transmembrane segments
0
Mean surface accessibility (rSASA)
0.36
Highest tissue expression
15 nTPM

Expression across tissuesHPA

Tissue

  • cerebral cortex: 15 nTPM
  • basal ganglia: 13 nTPM
  • amygdala: 9.7 nTPM
  • hippocampal formation: 9.6 nTPM
  • testis: 7.5 nTPM
  • hypothalamus: 6.1 nTPM

Single-cell type

  • brain inhibitory neurons: 129 nCPM
  • brain excitatory neurons: 103 nCPM
  • astrocytes: 80 nCPM
  • other brain neurons: 79 nCPM
  • bergmann glia: 57 nCPM
  • oligodendrocyte progenitor cells: 35 nCPM

Immune cell

  • neutrophil: 0.1 nTPM
  • basophil: 0 nTPM
  • classical monocyte: 0 nTPM
  • eosinophil: 0 nTPM
  • gdT-cell: 0 nTPM
  • intermediate monocyte: 0 nTPM

Brain region

  • cerebral cortex: 9.6 nTPM
  • white matter: 7.7 nTPM
  • hypothalamus: 6.1 nTPM
  • thalamus: 5.8 nTPM
  • hippocampal formation: 5.5 nTPM
  • basal ganglia: 5 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)
0.62
gnomAD pLI
0
gnomAD missense Z
1.16
DepMap mean gene effect
0.03
DepMap dependency class
none

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 PPP4R4 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 PPP4R4 as an antibody target. Whether an autoantibody or antibody against PPP4R4 could matter depends on whether native PPP4R4 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

PPP4R4 is annotated as predominantly intracellular. Intracellular proteins are common autoantibody markers, becoming visible to the immune system after cell injury or altered processing, but are usually markers of disease rather than direct drivers.

Annotation status

The present source text does not explicitly label PPP4R4 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/PPP4R4. 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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