We have identified a unique signature for DNA polymerase zeta which is to generate tandem mutations during somatic hypermutation. Using mice deficient for various polymerases, we observed that polymerase eta is a dominant protein, and the effect of polymerase zeta was more pronounced in the absence of polymerase eta. Furthermore, data suggest that polymerase zeta functions in the MSH2-MSH6 pathway. An advantage to using polymerase zeta to introduce tandem mutations would be to efficiently change amino acids in variable genes to generate higher affinity antibodies. Similarly, we are determining if polymerase iota interacts with the replication fork to compete with polymerase zeta. A study of how proliferating cell nuclear antigen clamp unloaders interfere with cell division and class switch recombination and hypermutation is underway. We are also measuring single-strand breaks in variable genes to see how polymerases gain access to synthesize.

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National Institute on Aging (NIA)
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National Institute on Aging
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Zanotti, Kimberly J; Gearhart, Patricia J (2016) Antibody diversification caused by disrupted mismatch repair and promiscuous DNA polymerases. DNA Repair (Amst) 38:110-6
Zanotti, Kimberly J; Maul, Robert W; Castiblanco, Diana P et al. (2015) ATAD5 deficiency decreases B cell division and Igh recombination. J Immunol 194:35-42
Maul, Robert W; Gearhart, Patricia J (2014) Refining the Neuberger model: Uracil processing by activated B cells. Eur J Immunol 44:1913-6
Saribasak, Huseyin; Maul, Robert W; Cao, Zheng et al. (2012) DNA polymerase ζ generates tandem mutations in immunoglobulin variable regions. J Exp Med 209:1075-81
Pape, Kathryn A; Taylor, Justin J; Maul, Robert W et al. (2011) Different B cell populations mediate early and late memory during an endogenous immune response. Science 331:1203-7
Maul, Robert W; Gearhart, Patricia J (2010) AID and somatic hypermutation. Adv Immunol 105:159-91
Maul, Robert W; Gearhart, Patricia J (2010) Controlling somatic hypermutation in immunoglobulin variable and switch regions. Immunol Res 47:113-22
Gearhart, Patricia J; Lindahl, Tomas; Neuberger, Michael S (2009) Preface. Philos Trans R Soc Lond B Biol Sci 364:561-2
Saribasak, Huseyin; Rajagopal, Deepa; Maul, Robert W et al. (2009) Hijacked DNA repair proteins and unchained DNA polymerases. Philos Trans R Soc Lond B Biol Sci 364:605-11