Seroatlas · Human Serome Atlas

POLM

DNA-directed DNA/RNA polymerase mu

Also known as: DPOLM_HUMAN, Tdt-N

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

Protein identityUniProt · HPA

UniProt accession: Q9NP87
Gene: POLM
Ensembl: ENSG00000122678
Chromosome: 7
Canonical length: 494 aa
Protein class: Enzymes, Metabolic proteins, Predicted intracellular proteins
Subcellular location: Nucleoplasm

OverviewNCBI Gene

Predicted to enable DNA-directed DNA polymerase activity. Predicted to be involved in double-strand break repair via nonhomologous end joining. Predicted to act upstream of or within B cell differentiation and somatic hypermutation of immunoglobulin genes. Predicted to be located in nucleoplasm. Predicted to be active in nucleus. [provided by Alliance of Genome Resources, Jul 2025]

Canonical amino-acid sequenceUniProt

494 residues, UniProt reviewed canonical sequence.

>Q9NP87|POLM
     1  MLPKRRRARV GSPSGDAASS TPPSTRFPGV AIYLVEPRMG RSRRAFLTGL ARSKGFRVLD
    61  ACSSEATHVV MEETSAEEAV SWQERRMAAA PPGCTPPALL DISWLTESLG AGQPVPVECR
   121  HRLEVAGPRK GPLSPAWMPA YACQRPTPLT HHNTGLSEAL EILAEAAGFE GSEGRLLTFC
   181  RAASVLKALP SPVTTLSQLQ GLPHFGEHSS RVVQELLEHG VCEEVERVRR SERYQTMKLF
   241  TQIFGVGVKT ADRWYREGLR TLDDLREQPQ KLTQQQKAGL QHHQDLSTPV LRSDVDALQQ
   301  VVEEAVGQAL PGATVTLTGG FRRGKLQGHD VDFLITHPKE GQEAGLLPRV MCRLQDQGLI
   361  LYHQHQHSCC ESPTRLAQQS HMDAFERSFC IFRLPQPPGA AVGGSTRPCP SWKAVRVDLV
   421  VAPVSQFPFA LLGWTGSKLF QRELRRFSRK EKGLWLNSHG LFDPEQKTFF QAASEEDIFR
   481  HLGLEYLPPE QRNA

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against POLM 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): 0.3
Highest tissue expression: 12 nTPM

Expression across tissuesHPA

Tissue

spleen: 12 nTPM
kidney: 11 nTPM
liver: 9.6 nTPM
thymus: 9.1 nTPM
thyroid gland: 9.1 nTPM
pancreas: 8.9 nTPM

Single-cell type

esophageal apical cells: 53 nCPM
tuft cells: 46 nCPM
neutrophils: 43 nCPM
rod photoreceptor cells: 41 nCPM
b-cells: 36 nCPM
breast lactating cells: 34 nCPM

Immune cell

neutrophil: 64 nTPM
basophil: 24 nTPM
naive B-cell: 11 nTPM
eosinophil: 11 nTPM
plasmacytoid DC: 9.6 nTPM
memory B-cell: 8 nTPM

Brain region

midbrain: 8 nTPM
thalamus: 7.9 nTPM
pons: 6.5 nTPM
medulla oblongata: 6.4 nTPM
cerebellum: 6.2 nTPM
amygdala: 5.5 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): 1.1
gnomAD pLI: 0
gnomAD missense Z: 0.19
DepMap mean gene effect: 0.02
DepMap dependency class: selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 7% 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 POLM as an antibody target. Whether an autoantibody or antibody against POLM could matter depends on whether native POLM is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

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

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