Seroatlas · Human Serome Atlas

MVB12B

Multivesicular body subunit 12B

Also known as: C9orf28, FAM125B, FLJ00001, MB12B_HUMAN

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

Protein identityUniProt · HPA

UniProt accession
Q9H7P6
Gene
MVB12B
Ensembl
ENSG00000196814
Chromosome
9
Canonical length
319 aa
Protein class
Predicted intracellular proteins
Subcellular location
Golgi apparatus,Vesicles

OverviewNCBI Gene

The protein encoded by this gene is a component of the ESCRT-I complex, a heterotetramer, which mediates the sorting of ubiquitinated cargo protein from the plasma membrane to the endosomal vesicle. ESCRT-I complex plays an essential role in HIV budding and endosomal protein sorting. Depletion and overexpression of this and related protein (MVB12A) inhibit HIV-1 infectivity and induce unusual viral assembly defects, indicating a role for MVB12 subunits in regulating ESCRT-mediated virus budding. Alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Aug 2011]

Canonical amino-acid sequenceUniProt

319 residues, UniProt reviewed canonical sequence.

>Q9H7P6|MVB12B
     1  MRSCFCVRRS RDPPPPQPPP PPPQRGTDQS TMPEVKDLSE ALPETSMDPI TGVGVVASRN
    61  RAPTGYDVVA QTADGVDADL WKDGLFKSKV TRYLCFTRSF SKENSHLGNV LVDMKLIDIK
   121  DTLPVGFIPI QETVDTQEVA FRKKRLCIKF IPRDSTEAAI CDIRIMGRTK QAPPQYTFIG
   181  ELNSMGIWYR MGRVPRNHDS SQPTTPSQSS AASTPAPNLP RHISLTLPAT FRGRNSTRTD
   241  YEYQHSNLYA ISAMDGVPFM ISEKFSCVPE SMQPFDLLGI TIKSLAEIEK EYEYSFRTEQ
   301  SAAARLPPSP TRCQQIPQS

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against MVB12B 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
Other membrane
Secreted
No
Transmembrane segments
0
Mean surface accessibility (rSASA)
0.49
Highest tissue expression
111 nTPM

Expression across tissuesHPA

Tissue

  • spinal cord: 111 nTPM
  • midbrain: 45 nTPM
  • hippocampal formation: 36 nTPM
  • basal ganglia: 26 nTPM
  • hypothalamus: 25 nTPM
  • amygdala: 24 nTPM

Single-cell type

  • oligodendrocytes: 603 nCPM
  • choroid plexus epithelial cells: 438 nCPM
  • renal collecting duct intercalated cells: 265 nCPM
  • microglia: 262 nCPM
  • ependymal cells: 226 nCPM
  • kupffer cells: 184 nCPM

Immune cell

  • MAIT T-cell: 2.6 nTPM
  • memory CD8 T-cell: 2.3 nTPM
  • gdT-cell: 1.4 nTPM
  • myeloid DC: 1 nTPM
  • naive CD8 T-cell: 1 nTPM
  • total PBMC: 0.9 nTPM

Brain region

  • white matter: 205 nTPM
  • medulla oblongata: 177 nTPM
  • pons: 143 nTPM
  • basal ganglia: 136 nTPM
  • midbrain: 130 nTPM
  • cerebellum: 129 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)
0.46
gnomAD pLI
0.56
gnomAD missense Z
1.67
DepMap mean gene effect
0.07
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 MVB12B 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 MVB12B as an antibody target. Whether an autoantibody or antibody against MVB12B could matter depends on whether native MVB12B is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

MVB12B 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 MVB12B as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/MVB12B. 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).

© 2026 · Seroatlas, Discover Oregon LLC · Terms of use

Loading the interactive Seroatlas protein explorer...