Seroatlas · Human Serome Atlas

HCRTR2

Orexin receptor type 2

Also known as: ORXR2, OX2R, OX2R_HUMAN, OXR2

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

Protein identityUniProt · HPA

UniProt accession
O43614
Gene
HCRTR2
Ensembl
ENSG00000137252
Chromosome
6
Canonical length
444 aa
Protein class
FDA approved drug targets, G-protein coupled receptors, Predicted membrane proteins
Subcellular location
Nucleoplasm,Plasma membrane

OverviewNCBI Gene

The protein encoded by this gene is a G-protein coupled receptor involved in the regulation of feeding behavior. The encoded protein binds the hypothalamic neuropeptides orexin A and orexin B. A related gene (HCRTR1) encodes a G-protein coupled receptor that selectively binds orexin A. [provided by RefSeq, Jan 2009]

Canonical amino-acid sequenceUniProt

444 residues, UniProt reviewed canonical sequence.

>O43614|HCRTR2
     1  MSGTKLEDSP PCRNWSSASE LNETQEPFLN PTDYDDEEFL RYLWREYLHP KEYEWVLIAG
    61  YIIVFVVALI GNVLVCVAVW KNHHMRTVTN YFIVNLSLAD VLVTITCLPA TLVVDITETW
   121  FFGQSLCKVI PYLQTVSVSV SVLTLSCIAL DRWYAICHPL MFKSTAKRAR NSIVIIWIVS
   181  CIIMIPQAIV MECSTVFPGL ANKTTLFTVC DERWGGEIYP KMYHICFFLV TYMAPLCLMV
   241  LAYLQIFRKL WCRQIPGTSS VVQRKWKPLQ PVSQPRGPGQ PTKSRMSAVA AEIKQIRARR
   301  KTARMLMIVL LVFAICYLPI SILNVLKRVF GMFAHTEDRE TVYAWFTFSH WLVYANSAAN
   361  PIIYNFLSGK FREEFKAAFS CCCLGVHHRQ EDRLTRGRTS TESRKSLTTQ ISNFDNISKL
   421  SEQVVLTSIS TLPAANGAGP LQNW

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against HCRTR2 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
Cell surface
Secreted
No
Transmembrane segments
7
Mean surface accessibility (rSASA)
0.39
Highest tissue expression
0.9 nTPM

Expression across tissuesHPA

Tissue

  • hypothalamus: 0.9 nTPM
  • kidney: 0.6 nTPM
  • midbrain: 0.5 nTPM
  • placenta: 0.4 nTPM
  • cerebral cortex: 0.3 nTPM
  • amygdala: 0.2 nTPM

Single-cell type

  • other brain neurons: 35 nCPM
  • brain inhibitory neurons: 24 nCPM
  • retinal amacrine cells: 22 nCPM
  • brain excitatory neurons: 17 nCPM
  • gonadotrophs: 8.5 nCPM
  • retinal pigment epithelial cells: 4.3 nCPM

Immune cell

  • basophil: 0 nTPM
  • classical monocyte: 0 nTPM
  • eosinophil: 0 nTPM
  • gdT-cell: 0 nTPM
  • intermediate monocyte: 0 nTPM
  • MAIT T-cell: 0 nTPM

Brain region

  • midbrain: 16 nTPM
  • pons: 9.9 nTPM
  • hypothalamus: 3.9 nTPM
  • basal ganglia: 3.7 nTPM
  • cerebral cortex: 3.7 nTPM
  • thalamus: 3.5 nTPM

ReferencesPubMed · IEDB

Publications for HCRTR2 from three distinct lines of evidence, kept separate because they answer different questions: whether antibodies are directed at the protein, whether a B-cell epitope has been mapped on it, and whether a T-cell epitope has. Each is labelled with its source.

Reference: AutoantibodyPubMed

2 publications

Sources: PubMed — antigen-level antibody evidence from a custom retrieval. Records matching a controlled set of autoantibody terms (the MeSH descriptors Autoantibodies and Autoantigens, with title and abstract term variants) were obtained through NCBI E-utilities, and their titles and abstracts parsed for constructions that direct an antibody at a named protein rather than for co-occurrence. Captured names were resolved against UniProt nomenclature and each antigen adjudicated individually against the source text. Bibliographic records from PubMed and MeSH, U.S. National Library of Medicine; citation metrics from NIH iCite (Hutchins et al., PLoS Biology 2016). Titles link to PubMed; abstracts are not reproduced here. The NLM does not endorse this analysis.

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)
0.64
gnomAD pLI
0.01
gnomAD missense Z
0.98
DepMap mean gene effect
-0.02
DepMap dependency class
selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 2% 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

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads HCRTR2 as an antibody target. Whether an autoantibody or antibody against HCRTR2 could matter depends on whether native HCRTR2 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

HCRTR2 is annotated at the cell surface, where native HCRTR2 is exposed to circulating antibodies and is a prime autoantibody target that could block, deplete, or overstimulate it.

Annotation status

The present source text does not explicitly label HCRTR2 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/HCRTR2. 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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