Seroatlas · Human Serome Atlas

UPF3B

Regulator of nonsense transcripts 3B

Also known as: HUPF3B, MRX62, MRX82, REN3B_HUMAN, RENT3B, UPF3BP1, UPF3BP2, UPF3BP3, UPF3X

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

Protein identityUniProt · HPA

UniProt accession
Q9BZI7
Gene
UPF3B
Ensembl
ENSG00000125351
Chromosome
X
Canonical length
483 aa
Protein class
Disease related genes, Human disease related genes, Predicted intracellular proteins
Subcellular location
Nucleoplasm,Nucleoli,Cytosol

OverviewNCBI Gene

This gene encodes a protein that is part of a post-splicing multiprotein complex involved in both mRNA nuclear export and mRNA surveillance. The encoded protein is one of two functional homologs to yeast Upf3p. mRNA surveillance detects exported mRNAs with truncated open reading frames and initiates nonsense-mediated mRNA decay (NMD). When translation ends upstream from the last exon-exon junction, this triggers NMD to degrade mRNAs containing premature stop codons. This protein binds to the mRNA and remains bound after nuclear export, acting as a nucleocytoplasmic shuttling protein. It forms with Y14 a complex that binds specifically 20 nt upstream of exon-exon junctions. This gene is located on the long arm of chromosome X. Two splice variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2008]

Canonical amino-acid sequenceUniProt

483 residues, UniProt reviewed canonical sequence.

>Q9BZI7|UPF3B
     1  MKEEKEHRPK EKRVTLLTPA GATGSGGGTS GDSSKGEDKQ DRNKEKKEAL SKVVIRRLPP
    61  TLTKEQLQEH LQPMPEHDYF EFFSNDTSLY PHMYARAYIN FKNQEDIILF RDRFDGYVFL
   121  DNKGQEYPAI VEFAPFQKAA KKKTKKRDTK VGTIDDDPEY RKFLESYATD NEKMTSTPET
   181  LLEEIEAKNR ELIAKKTTPL LSFLKNKQRM REEKREERRR REIERKRQRE EERRKWKEEE
   241  KRKRKDIEKL KKIDRIPERD KLKDEPKIKV HRFLLQAVNQ KNLLKKPEKG DEKELDKREK
   301  AKKLDKENLS DERASGQSCT LPKRSDSELK DEKPKRPEDE SGRDYRERER EYERDQERIL
   361  RERERLKRQE EERRRQKERY EKEKTFKRKE EEMKKEKDTL RDKGKKAEST ESIGSSEKTE
   421  KKEEVVKRDR IRNKDRPAMQ LYQPGARSRN RLCPPDDSTK SGDSAAERKQ ESGISHRKEG
   481  GEE

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against UPF3B 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)
0.58
Highest tissue expression
24 nTPM

Expression across tissuesHPA

Tissue

  • cerebellum: 24 nTPM
  • choroid plexus: 17 nTPM
  • retina: 17 nTPM
  • hypothalamus: 15 nTPM
  • tonsil: 14 nTPM
  • basal ganglia: 14 nTPM

Single-cell type

  • oocytes: 226 nCPM
  • early spermatids: 144 nCPM
  • late primary spermatocytes: 140 nCPM
  • syncytiotrophoblasts: 107 nCPM
  • rod photoreceptor cells: 104 nCPM
  • early primary spermatocytes: 98 nCPM

Immune cell

  • naive B-cell: 13 nTPM
  • memory B-cell: 12 nTPM
  • plasmacytoid DC: 8.7 nTPM
  • basophil: 8.1 nTPM
  • NK-cell: 7.6 nTPM
  • T-reg: 7 nTPM

Brain region

  • hypothalamus: 18 nTPM
  • cerebellum: 18 nTPM
  • cerebral cortex: 16 nTPM
  • white matter: 14 nTPM
  • thalamus: 13 nTPM
  • pons: 13 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about UPF3B.

Disease | AllUniProt

Conditions UPF3B is implicated in, by any mechanism.

  • Intellectual developmental disorder, X-linked, syndromic 14 (MRXS14) MIM:300676

Disease | GeneticClinVar

36 pathogenic / likely-pathogenic of 428 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)
0.29
gnomAD pLI
0.98
gnomAD missense Z
1.84
DepMap mean gene effect
-0.11
DepMap dependency class
selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 6% 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 UPF3B 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 UPF3B as an antibody target. Whether an autoantibody or antibody against UPF3B could matter depends on whether native UPF3B is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

UPF3B 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 UPF3B as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/UPF3B. 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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