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
vertebrateimmune 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.
^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.
PMID15242403.
S2CID36516952.
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
vertebrateimmune 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.
^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.
PMID15242403.
S2CID36516952.