Seroatlas · Human Serome Atlas

SF3B4

Splicing factor 3B subunit 4

Also known as: Hsh49, SAP49, SF3B4_HUMAN, SF3b49

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

Protein identityUniProt · HPA

UniProt accession
Q15427
Gene
SF3B4
Ensembl
ENSG00000143368
Chromosome
1
Canonical length
424 aa
Protein class
Disease related genes, Human disease related genes, Plasma proteins, Predicted intracellular proteins
Subcellular location
Nuclear speckles

OverviewNCBI Gene

This gene encodes one of four subunits of the splicing factor 3B. The protein encoded by this gene cross-links to a region in the pre-mRNA immediately upstream of the branchpoint sequence in pre-mRNA in the prespliceosomal complex A. It also may be involved in the assembly of the B, C and E spliceosomal complexes. In addition to RNA-binding activity, this protein interacts directly and highly specifically with subunit 2 of the splicing factor 3B. This protein contains two N-terminal RNA-recognition motifs (RRMs), consistent with the observation that it binds directly to pre-mRNA. [provided by RefSeq, Jul 2008]

Canonical amino-acid sequenceUniProt

424 residues, UniProt reviewed canonical sequence.

>Q15427|SF3B4
     1  MAAGPISERN QDATVYVGGL DEKVSEPLLW ELFLQAGPVV NTHMPKDRVT GQHQGYGFVE
    61  FLSEEDADYA IKIMNMIKLY GKPIRVNKAS AHNKNLDVGA NIFIGNLDPE IDEKLLYDTF
   121  SAFGVILQTP KIMRDPDTGN SKGYAFINFA SFDASDAAIE AMNGQYLCNR PITVSYAFKK
   181  DSKGERHGSA AERLLAAQNP LSQADRPHQL FADAPPPPSA PNPVVSSLGS GLPPPGMPPP
   241  GSFPPPVPPP GALPPGIPPA MPPPPMPPGA AGHGPPSAGT PGAGHPGHGH SHPHPFPPGG
   301  MPHPGMSQMQ LAHHGPHGLG HPHAGPPGSG GQPPPRPPPG MPHPGPPPMG MPPRGPPFGS
   361  PMGHPGPMPP HGMRGPPPLM PPHGYTGPPR PPPYGYQRGP LPPPRPTPRP PVPPRGPLRG
   421  PLPQ

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against SF3B4 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)
0.54
Highest tissue expression
70 nTPM

Expression across tissuesHPA

Tissue

  • bone marrow: 70 nTPM
  • colon: 66 nTPM
  • blood vessel: 64 nTPM
  • endometrium: 61 nTPM
  • esophagus: 60 nTPM
  • testis: 60 nTPM

Single-cell type

  • late primary spermatocytes: 117 nCPM
  • syncytiotrophoblasts: 109 nCPM
  • oocytes: 106 nCPM
  • extravillous trophoblasts: 92 nCPM
  • cytotrophoblasts: 91 nCPM
  • migrating cytotrophoblasts: 87 nCPM

Immune cell

  • eosinophil: 131 nTPM
  • non-classical monocyte: 121 nTPM
  • neutrophil: 112 nTPM
  • intermediate monocyte: 110 nTPM
  • NK-cell: 105 nTPM
  • T-reg: 100 nTPM

Brain region

  • cerebral cortex: 42 nTPM
  • medulla oblongata: 36 nTPM
  • hypothalamus: 34 nTPM
  • cerebellum: 33 nTPM
  • white matter: 32 nTPM
  • choroid plexus: 32 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about SF3B4.

Disease | AllUniProt

Conditions SF3B4 is implicated in, by any mechanism.

  • Acrofacial dysostosis 1, Nager type (AFD1) MIM:154400

Disease | GeneticClinVar

47 pathogenic / likely-pathogenic of 158 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

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)
0.21
gnomAD pLI
0.99
gnomAD missense Z
3.87
DepMap mean gene effect
-1.84
DepMap dependency class
pan

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 15% 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 SF3B4 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 SF3B4 as an antibody target. Whether an autoantibody or antibody against SF3B4 could matter depends on whether native SF3B4 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

SF3B4 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 SF3B4 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/SF3B4. 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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