DNA polymerase mu

POLM
Available structures
PDB	Ortholog search: PDBe RCSB
List of PDB id codes
	2HTF, 4LZD, 4M04, 4M0A, 4YCX, 4YD1, 4YD2, 2DUN
Identifiers
Aliases	POLM, Pol Mu, Tdt-N, DNA polymerase mu, polymerase (DNA) mu
External IDs	OMIM: 606344; MGI: 1860191; HomoloGene: 41170; GeneCards: POLM; OMA:POLM - orthologs
Gene location (Human)
Chr.	Chromosome 7 (human)
End	44,082,530 bp
Gene location (Mouse)
Chr.	Chromosome 11 (mouse)
End	5,788,016 bp
RNA expression pattern
	Top expressed in
	granulocyte; ; right lobe of thyroid gland; ; spleen; ; left lobe of thyroid gland; ; blood; ; right uterine tube; ; right lobe of liver; ; lymph node; ; fundus; ; gastric mucosa;
	Top expressed in
	zygote; ; Ileal epithelium; ; secondary oocyte; ; granulocyte; ; perirhinal cortex; ; lactiferous gland; ; entorhinal cortex; ; primary oocyte; ; lip; ; choroid plexus of fourth ventricle;
	More reference expression data
	More reference expression data
Gene ontology
Molecular function	transferase activity; DNA binding; DNA-directed DNA polymerase activity; nucleotidyltransferase activity; protein binding; metal ion binding; DNA polymerase; DNA polymerase activity;
Cellular component	nucleus; nucleoplasm;
Biological process	somatic hypermutation of immunoglobulin genes; B cell differentiation; DNA recombination; double-strand break repair via nonhomologous end joining; cellular response to DNA damage stimulus; DNA repair; DNA biosynthetic process;
	Sources:Amigo / QuickGO
Orthologs
	27434
	54125
	ENSG00000122678
	ENSMUSG00000020474
	Q9NP87
	Q9JIW4
	NM_001284330; NM_001284331; NM_013284; NM_001362683
	NM_017401
	NP_001271259; NP_001271260; NP_037416; NP_001349612
	NP_059097
	Wikidata
View/Edit Human	View/Edit Mouse

DNA polymerase mu is a polymerase enzyme found in eukaryotes. In humans, this protein is encoded by the POLM gene.^[5]

Function

Pol μ is a member of the X family of DNA polymerases. It participates in resynthesis of damaged or missing nucleotides during the non-homologous end joining (NHEJ) pathway of DNA repair.^[6] Pol μ interacts with Ku and DNA ligase IV, which also participate in NHEJ.^[7] It is structurally and functionally related to pol λ, and, like pol λ, pol μ has a BRCT domain that is thought to mediate interactions with other DNA repair proteins.^[8] Unlike pol λ, however, pol μ has the unique ability to add a base to a blunt end that is templated by the overhang on the opposite end of the double-strand break.^[9] Pol μ is also closely related to terminal deoxynucleotidyl transferase (TdT), a specialized DNA polymerase that adds random nucleotides to DNA ends during V(D)J recombination, the process by which B-cell and T-cell receptor diversity is generated in the vertebrate immune system. Like TdT, pol μ participates in V(D)J recombination, but only during light chain rearrangements.^[10] This is distinct from pol λ, which is involved in heavy chain rearrangements.^[11]

POLM mutant mice

In polymerase mu mutant mice, hematopoietic cell development is defective in several peripheral and bone marrow cell populations with about a 40% decrease in bone marrow cell number that includes several hematopoietic lineages.^[12] Expansion potential of hematopoietic progenitor cells is also reduced. These characteristics correlate with reduced ability to repair double-strand breaks in hematopoietic tissue. Whole body gamma irradiation of polymerase mu mutant mice indicates that polymerase mu also has a role in double-strand break repair in other tissues unrelated to hematopoietic tissue. Thus polymerase mu has a significant role in maintaining genetic stability in hematopoietic and non-hematopoietic tissue.

References

^ ^a ^b ^c GRCh38: Ensembl release 89: ENSG00000122678 – Ensembl, May 2017
^ ^a ^b ^c GRCm38: Ensembl release 89: ENSMUSG00000020474 – Ensembl, May 2017
^ "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
^ "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
^ "Entrez Gene: POLM polymerase (DNA directed), mu".
^ Daley JM, Laan RL, Suresh A, Wilson TE (August 2005). "DNA joint dependence of pol X family polymerase action in nonhomologous end joining". J. Biol. Chem. 280 (32): 29030–7. doi:10.1074/jbc.M505277200. PMID 15964833.
^ Mahajan KN, Nick McElhinny SA, Mitchell BS, Ramsden DA (July 2002). "Association of DNA polymerase mu (pol mu) with Ku and ligase IV: role for pol mu in end-joining double-strand break repair". Mol. Cell. Biol. 22 (14): 5194–202. doi:10.1128/MCB.22.14.5194-5202.2002. PMC 139779. PMID 12077346.
^ Nick McElhinny SA, Ramsden DA (August 2004). "Sibling rivalry: competition between Pol X family members in V(D)J recombination and general double strand break repair". Immunol. Rev. 200: 156–64. doi:10.1111/j.0105-2896.2004.00160.x. PMID 15242403. S2CID 36516952.
^ Nick McElhinny SA, Havener JM, Garcia-Diaz M, et al. (August 2005). "A gradient of template dependence defines distinct biological roles for family X polymerases in nonhomologous end joining". Mol. Cell. 19 (3): 357–66. doi:10.1016/j.molcel.2005.06.012. PMID 16061182.
^ Bertocci B, De Smet A, Berek C, Weill JC, Reynaud CA (August 2003). "Immunoglobulin kappa light chain gene rearrangement is impaired in mice deficient for DNA polymerase mu". Immunity. 19 (2): 203–11. doi:10.1016/S1074-7613(03)00203-6. PMID 12932354.
^ Bertocci B, De Smet A, Weill JC, Reynaud CA (July 2006). "Nonoverlapping functions of DNA polymerases mu, lambda, and terminal deoxynucleotidyltransferase during immunoglobulin V(D)J recombination in vivo" (PDF). Immunity. 25 (1): 31–41. doi:10.1016/j.immuni.2006.04.013. PMID 16860755.
^ Lucas D, Escudero B, Ligos JM, Segovia JC, Estrada JC, Terrados G, Blanco L, Samper E, Bernad A (Feb 2009). "Altered hematopoiesis in mice lacking DNA polymerase mu is due to inefficient double-strand break repair". PLOS Genet. 5 (2): e1000389. doi:10.1371/journal.pgen.1000389. PMC 2638008. PMID 19229323.

External links

Overview of all the structural information available in the PDB for UniProt: Q9NP87 (Human DNA-directed DNA/RNA polymerase mu) at the PDBe-KB.

This article on a gene on human chromosome 7 is a stub. You can help Wikipedia by expanding it.

[refGRCh38Ensembl-1] GRCh38: Ensembl release 89: ENSG00000122678 – Ensembl, May 2017

[refGRCm38Ensembl-2] GRCm38: Ensembl release 89: ENSMUSG00000020474 – Ensembl, May 2017

[3] "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.

[4] "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.

[entrez-5] "Entrez Gene: POLM polymerase (DNA directed), mu".

[pmid15964833-6] Daley JM, Laan RL, Suresh A, Wilson TE (August 2005). "DNA joint dependence of pol X family polymerase action in nonhomologous end joining". J. Biol. Chem. 280 (32): 29030–7. doi:10.1074/jbc.M505277200. PMID 15964833.

[pmid12077346-7] Mahajan KN, Nick McElhinny SA, Mitchell BS, Ramsden DA (July 2002). "Association of DNA polymerase mu (pol mu) with Ku and ligase IV: role for pol mu in end-joining double-strand break repair". Mol. Cell. Biol. 22 (14): 5194–202. doi:10.1128/MCB.22.14.5194-5202.2002. PMC 139779. PMID 12077346.

[pmid15242403-8] Nick McElhinny SA, Ramsden DA (August 2004). "Sibling rivalry: competition between Pol X family members in V(D)J recombination and general double strand break repair". Immunol. Rev. 200: 156–64. doi:10.1111/j.0105-2896.2004.00160.x. PMID 15242403. S2CID 36516952.

[pmid16061182-9] Nick McElhinny SA, Havener JM, Garcia-Diaz M, et al. (August 2005). "A gradient of template dependence defines distinct biological roles for family X polymerases in nonhomologous end joining". Mol. Cell. 19 (3): 357–66. doi:10.1016/j.molcel.2005.06.012. PMID 16061182.

[pmid12932354-10] Bertocci B, De Smet A, Berek C, Weill JC, Reynaud CA (August 2003). "Immunoglobulin kappa light chain gene rearrangement is impaired in mice deficient for DNA polymerase mu". Immunity. 19 (2): 203–11. doi:10.1016/S1074-7613(03)00203-6. PMID 12932354.

[pmid16860755-11] Bertocci B, De Smet A, Weill JC, Reynaud CA (July 2006). "Nonoverlapping functions of DNA polymerases mu, lambda, and terminal deoxynucleotidyltransferase during immunoglobulin V(D)J recombination in vivo" (PDF). Immunity. 25 (1): 31–41. doi:10.1016/j.immuni.2006.04.013. PMID 16860755.

[12] Lucas D, Escudero B, Ligos JM, Segovia JC, Estrada JC, Terrados G, Blanco L, Samper E, Bernad A (Feb 2009). "Altered hematopoiesis in mice lacking DNA polymerase mu is due to inefficient double-strand break repair". PLOS Genet. 5 (2): e1000389. doi:10.1371/journal.pgen.1000389. PMC 2638008. PMID 19229323.

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