Seroatlas · Human Serome Atlas

POLR1B

DNA-directed RNA polymerase I subunit RPA2

Also known as: FLJ10816, FLJ21921, RPA135, RPA2, RPA2_HUMAN, Rpo1-2

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

Protein identityUniProt · HPA

UniProt accession: Q9H9Y6
Gene: POLR1B
Ensembl: ENSG00000125630
Chromosome: 2
Canonical length: 1135 aa
Protein class: Disease related genes, Enzymes, Human disease related genes, Metabolic proteins, Plasma proteins, Potential drug targets, Predicted intracellular proteins, RNA polymerase related proteins
Subcellular location: Nucleoli fibrillar center,Cytosol

OverviewNCBI Gene

Eukaryotic RNA polymerase I (pol I) is responsible for the transcription of ribosomal RNA (rRNA) genes and production of rRNA, the primary component of ribosomes. Pol I is a multisubunit enzyme composed of 6 to 14 polypeptides, depending on the species. Most of the mass of the pol I complex derives from the 2 largest subunits, Rpa1 and Rpa2 in yeast. POLR1B is homologous to Rpa2 (Seither and Grummt, 1996 [PubMed 8921381]).[supplied by OMIM, Mar 2008]

Canonical amino-acid sequenceUniProt

1135 residues, UniProt reviewed canonical sequence.

>Q9H9Y6|POLR1B
     1  MDPGSRWRNL PSGPSLKHLT DPSYGIPREQ QKAALQELTR AHVESFNYAV HEGLGLAVQA
    61  IPPFEFAFKD ERISFTILDA VISPPTVPKG TICKEANVYP AECRGRRSTY RGKLTADINW
   121  AVNGISKGII KQFLGYVPIM VKSKLCNLRN LPPQALIEHH EEAEEMGGYF IINGIEKVIR
   181  MLIMPRRNFP IAMIRPKWKT RGPGYTQYGV SMHCVREEHS AVNMNLHYLE NGTVMLNFIY
   241  RKELFFLPLG FALKALVSFS DYQIFQELIK GKEDDSFLRN SVSQMLRIVM EEGCSTQKQV
   301  LNYLGECFRV KLNVPDWYPN EQAAEFLFNQ CICIHLKSNT EKFYMLCLMT RKLFALAKGE
   361  CMEDNPDSLV NQEVLTPGQL FLMFLKEKLE GWLVSIKIAF DKKAQKTSVS MNTDNLMRIF
   421  TMGIDLTKPF EYLFATGNLR SKTGLGLLQD SGLCVVADKL NFIRYLSHFR CVHRGADFAK
   481  MRTTTVRRLL PESWGFLCPV HTPDGEPCGL MNHLTAVCEV VTQFVYTASI PALLCNLGVT
   541  PIDGAPHRSY SECYPVLLDG VMVGWVDKDL APGIADSLRH FKVLREKRIP PWMEVVLIPM
   601  TGKPSLYPGL FLFTTPCRLV RPVQNLALGK EELIGTMEQI FMNVAIFEDE VFAGVTTHQE
   661  LFPHSLLSVI ANFIPFSDHN QSPRNMYQCQ MGKQTMGFPL LTYQDRSDNK LYRLQTPQSP
   721  LVRPSMYDYY DMDNYPIGTN AIVAVISYTG YDMEDAMIVN KASWERGFAH GSVYKSEFID
   781  LSEKIKQGDS SLVFGIKPGD PRVLQKLDDD GLPFIGAKLQ YGDPYYSYLN LNTGESFVMY
   841  YKSKENCVVD NIKVCSNDTG SGKFKCVCIT MRVPRNPTIG DKFASRHGQK GILSRLWPAE
   901  DMPFTESGMV PDILFNPHGF PSRMTIGMLI ESMAGKSAAL HGLCHDATPF IFSEENSALE
   961  YFGEMLKAAG YNFYGTERLY SGISGLELEA DIFIGVVYYQ RLRHMVSDKF QVRTTGARDR
  1021  VTNQPIGGRN VQGGIRFGEM ERDALLAHGT SFLLHDRLFN CSDRSVAHVC VKCGSLLSPL
  1081  LEKPPPSWSA MRNRKYNCTL CSRSDTIDTV SVPYVFRYFV AELAAMNIKV KLDVV

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against POLR1B 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): 0.23
Highest tissue expression: 11 nTPM

Expression across tissuesHPA

Tissue

parathyroid gland: 11 nTPM
tonsil: 10 nTPM
liver: 10 nTPM
thyroid gland: 9.9 nTPM
lymph node: 8.7 nTPM
testis: 7.9 nTPM

Single-cell type

early spermatids: 193 nCPM
late primary spermatocytes: 132 nCPM
late spermatids: 41 nCPM
erythrocyte progenitors: 39 nCPM
megakaryocyte progenitors: 37 nCPM
megakaryocyte-erythroid progenitors: 34 nCPM

Immune cell

MAIT T-cell: 22 nTPM
NK-cell: 15 nTPM
T-reg: 15 nTPM
myeloid DC: 14 nTPM
naive CD8 T-cell: 13 nTPM
naive CD4 T-cell: 12 nTPM

Brain region

choroid plexus: 11 nTPM
hypothalamus: 9.9 nTPM
cerebellum: 9.5 nTPM
cerebral cortex: 9.2 nTPM
white matter: 9.1 nTPM
basal ganglia: 8.7 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about POLR1B.

Disease | AllUniProt

Conditions POLR1B is implicated in, by any mechanism.

Treacher Collins syndrome 4 (TCS4) MIM:618939

Disease | GeneticClinVar

5 pathogenic / likely-pathogenic of 185 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

Treacher Collins syndrome 4
Treacher Collins syndrome
POLR1B-related disorder

Disease | ImmuneIEDB

Conditions an epitope on POLR1B was assayed in.

melanoma T cell

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): 0.25
gnomAD pLI: 1
gnomAD missense Z: 2.97
DepMap mean gene effect: -1.49
DepMap dependency class: pan

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

DNA-directed RNA polymerase, subunit 2, hybrid-binding domain
RNA polymerase, beta subunit, conserved site
RNA polymerase Rpb2, domain 7
RNA polymerase Rpb2, domain 2
RNA polymerase, beta subunit, protrusion
RNA polymerase Rpb2, domain 3
RNA polymerase Rpb2, OB-fold
DNA-directed RNA polymerase, subunit 2
DNA-directed RNA polymerase, subunit 2, hybrid-binding domain superfamily
RNA polymerase Rpb2, domain 2 superfamily
RNA polymerase Rpb2, domain 6
RNA polymerase Rpb2, domain 7
RNA polymerase Rpb2, domain 2
RNA polymerase beta subunit
RNA polymerase Rpb2, domain 3
DNA-directed RNA polymerase I subunit RPA2, domain 4
RNA polymerase I, Rpa2 specific domain

KeywordsUniProt

InteractionsUniProt · HPA

Protein binding partners of POLR1B 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 POLR1B as an antibody target. Whether an autoantibody or antibody against POLR1B could matter depends on whether native POLR1B is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

POLR1B 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 POLR1B as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

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