Naoko Shima

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Credentials

PhD

Research Summary

Dr. Shima's research focuses on the two genes, Polq and Mcm4.Polq encodes DNA polymerase theta, a polymerase unique in that it also possesses a helicase domain in a single polypeptide. POLQ is an error-prone polymerase that can efficiently bypass an abasic site. This translation activity plays a crucial role in immunoglobulin gene somatic hypermutation, which underlies the generation of high-affinity antibodies. Polq has two paralogs Poln and Helq. The Lab is planning to investigate these paralogs function in genome maintenance.Mcm4 is an essential gene that is required for DNA replication. Dr. Shima's lab has recovered a hypomorphic allele of Mcm4, which could cause replication defect or stress. These mutant mice are highly prone to spontaneous tumors. They are currently investigating the connection among replication stress, chromosome instability, and cancer using this novel mutant as a model.