Seroatlas · Human Serome Atlas

ORC2

Origin recognition complex subunit 2

Also known as: ORC2_HUMAN, ORC2L

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

Protein identityUniProt · HPA

UniProt accession
Q13416
Gene
ORC2
Ensembl
ENSG00000115942
Chromosome
2
Canonical length
577 aa
Protein class
Predicted intracellular proteins
Subcellular location
Nucleoplasm,Cytosol

OverviewNCBI Gene

The origin recognition complex (ORC) is a highly conserved six subunits protein complex essential for the initiation of the DNA replication in eukaryotic cells. Studies in yeast demonstrated that ORC binds specifically to origins of replication and serves as a platform for the assembly of additional initiation factors such as Cdc6 and Mcm proteins. The protein encoded by this gene is a subunit of the ORC complex. This protein forms a core complex with ORC3, -4, and -5. It also interacts with CDC45 and MCM10, which are proteins known to be important for the initiation of DNA replication. This protein has been demonstrated to specifically associate with the origin of replication of Epstein-Barr virus in human cells, and is thought to be required for DNA replication from viral origin of replication. Alternatively spliced transcript variants have been found, one of which is a nonsense-mediated mRNA decay candidate. [provided by RefSeq, Oct 2010]

Canonical amino-acid sequenceUniProt

577 residues, UniProt reviewed canonical sequence.

>Q13416|ORC2
     1  MSKPELKEDK MLEVHFVGDD DVLNHILDRE GGAKLKKERA QLLVNPKKII KKPEYDLEED
    61  DQEVLKDQNY VEIMGRDVQE SLKNGSATGG GNKVYSFQNR KHSEKMAKLA SELAKTPQKS
   121  VSFSLKNDPE ITINVPQSSK GHSASDKVQP KNNDKSEFLS TAPRSLRKRL IVPRSHSDSE
   181  SEYSASNSED DEGVAQEHEE DTNAVIFSQK IQAQNRVVSA PVGKETPSKR MKRDKTSDLV
   241  EEYFEAHSSS KVLTSDRTLQ KLKRAKLDQQ TLRNLLSKVS PSFSAELKQL NQQYEKLFHK
   301  WMLQLHLGFN IVLYGLGSKR DLLERFRTTM LQDSIHVVIN GFFPGISVKS VLNSITEEVL
   361  DHMGTFRSIL DQLDWIVNKF KEDSSLELFL LIHNLDSQML RGEKSQQIIG QLSSLHNIYL
   421  IASIDHLNAP LMWDHAKQSL FNWLWYETTT YSPYTEETSY ENSLLVKQSG SLPLSSLTHV
   481  LRSLTPNARG IFRLLIKYQL DNQDNPSYIG LSFQDFYQQC REAFLVNSDL TLRAQLTEFR
   541  DHKLIRTKKG TDGVEYLLIP VDNGTLTDFL EKEEEEA

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against ORC2 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)
0.48
Highest tissue expression
20 nTPM

Expression across tissuesHPA

Tissue

  • testis: 20 nTPM
  • thymus: 8.7 nTPM
  • duodenum: 8.6 nTPM
  • heart muscle: 8.2 nTPM
  • lymph node: 7.9 nTPM
  • skin: 7.9 nTPM

Single-cell type

  • neutrophils: 251 nCPM
  • cardiomyocytes: 197 nCPM
  • myonuclei: 196 nCPM
  • late primary spermatocytes: 174 nCPM
  • sertoli cells: 168 nCPM
  • choroid plexus epithelial cells: 137 nCPM

Immune cell

  • naive CD4 T-cell: 5.7 nTPM
  • memory B-cell: 5.5 nTPM
  • plasmacytoid DC: 4.9 nTPM
  • naive B-cell: 4.6 nTPM
  • memory CD4 T-cell: 4.5 nTPM
  • MAIT T-cell: 4.3 nTPM

Brain region

  • cerebellum: 27 nTPM
  • white matter: 22 nTPM
  • choroid plexus: 21 nTPM
  • cerebral cortex: 21 nTPM
  • hypothalamus: 18 nTPM
  • basal ganglia: 18 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)
0.36
gnomAD pLI
0.84
gnomAD missense Z
1.06
DepMap mean gene effect
-0.41
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

  • Origin recognition complex, subunit 2
  • Origin recognition complex subunit 2, RecA-like domain
  • Origin recognition complex subunit 2, winged-helix domain
  • Origin recognition complex subunit 2 RecA-like domain
  • ORC2 WHD

KeywordsUniProt

InteractionsUniProt · HPA

Protein binding partners of ORC2 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 ORC2 as an antibody target. Whether an autoantibody or antibody against ORC2 could matter depends on whether native ORC2 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

ORC2 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 ORC2 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/ORC2. 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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