Seroatlas · Human Serome Atlas

UBQLN2

Ubiquilin-2

Also known as: Chap1, CHAP1/DSK2, Dsk2, LIC-2, N4BP4, PLIC-2, PLIC2, RIHFB2157, UBQL2_HUMAN

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

Protein identityUniProt · HPA

UniProt accession
Q9UHD9
Gene
UBQLN2
Ensembl
ENSG00000188021
Chromosome
X
Canonical length
624 aa
Protein class
Disease related genes, Human disease related genes, Plasma proteins, Predicted intracellular proteins
Subcellular location
Plasma membrane,Cytosol
Quaternary structure
Homodimer

OverviewNCBI Gene

This gene encodes an ubiquitin-like protein (ubiquilin) that shares high degree of similarity with related products in yeast, rat and frog. Ubiquilins contain a N-terminal ubiquitin-like domain and a C-terminal ubiquitin-associated domain. They physically associate with both proteasomes and ubiquitin ligases; and thus, are thought to functionally link the ubiquitination machinery to the proteasome to affect in vivo protein degradation. This ubiquilin has also been shown to bind the ATPase domain of the Hsp70-like Stch protein. [provided by RefSeq, Oct 2009]

Canonical amino-acid sequenceUniProt

624 residues, UniProt reviewed canonical sequence.

>Q9UHD9|UBQLN2
     1  MAENGESSGP PRPSRGPAAA QGSAAAPAEP KIIKVTVKTP KEKEEFAVPE NSSVQQFKEA
    61  ISKRFKSQTD QLVLIFAGKI LKDQDTLIQH GIHDGLTVHL VIKSQNRPQG QSTQPSNAAG
   121  TNTTSASTPR SNSTPISTNS NPFGLGSLGG LAGLSSLGLS STNFSELQSQ MQQQLMASPE
   181  MMIQIMENPF VQSMLSNPDL MRQLIMANPQ MQQLIQRNPE ISHLLNNPDI MRQTLEIARN
   241  PAMMQEMMRN QDLALSNLES IPGGYNALRR MYTDIQEPML NAAQEQFGGN PFASVGSSSS
   301  SGEGTQPSRT ENRDPLPNPW APPPATQSSA TTSTTTSTGS GSGNSSSNAT GNTVAAANYV
   361  ASIFSTPGMQ SLLQQITENP QLIQNMLSAP YMRSMMQSLS QNPDLAAQMM LNSPLFTANP
   421  QLQEQMRPQL PAFLQQMQNP DTLSAMSNPR AMQALMQIQQ GLQTLATEAP GLIPSFTPGV
   481  GVGVLGTAIG PVGPVTPIGP IGPIVPFTPI GPIGPIGPTG PAAPPGSTGS GGPTGPTVSS
   541  AAPSETTSPT SESGPNQQFI QQMVQALAGA NAPQLPNPEV RFQQQLEQLN AMGFLNREAN
   601  LQALIATGGD INAAIERLLG SQPS

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against UBQLN2 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
33 nTPM

Expression across tissuesHPA

Tissue

  • cerebellum: 33 nTPM
  • basal ganglia: 33 nTPM
  • cerebral cortex: 31 nTPM
  • hypothalamus: 26 nTPM
  • skeletal muscle: 26 nTPM
  • amygdala: 24 nTPM

Single-cell type

  • neutrophils: 68 nCPM
  • pancreatic islet cells: 58 nCPM
  • syncytiotrophoblasts: 51 nCPM
  • smooth muscle cells: 50 nCPM
  • esophageal apical cells: 46 nCPM
  • esophageal suprabasal cells: 44 nCPM

Immune cell

  • basophil: 50 nTPM
  • non-classical monocyte: 34 nTPM
  • intermediate monocyte: 31 nTPM
  • naive CD4 T-cell: 30 nTPM
  • eosinophil: 24 nTPM
  • classical monocyte: 24 nTPM

Brain region

  • cerebral cortex: 67 nTPM
  • basal ganglia: 63 nTPM
  • hypothalamus: 61 nTPM
  • white matter: 59 nTPM
  • hippocampal formation: 58 nTPM
  • pons: 55 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about UBQLN2.

Disease | AllUniProt

Conditions UBQLN2 is implicated in, by any mechanism.

  • Amyotrophic lateral sclerosis 15, with or without frontotemporal dementia (ALS15) MIM:300857

Disease | GeneticClinVar

7 pathogenic / likely-pathogenic of 252 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

  • Amyotrophic lateral sclerosis type 15
  • UBQLN2-related disorder

Disease | ImmuneIEDB

Conditions an epitope on UBQLN2 was assayed in.

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)
0.45
gnomAD pLI
0.85
gnomAD missense Z
1.5
DepMap mean gene effect
0.09
DepMap dependency class
selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 5% 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 UBQLN2 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 UBQLN2 as an antibody target. Whether an autoantibody or antibody against UBQLN2 could matter depends on whether native UBQLN2 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

UBQLN2 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 UBQLN2 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/UBQLN2. 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...