title: Knock-down of human MutY homolog (hMYH) decreases phosphorylation of checkpoint kinase 1 (Chk1) induced by hydroxyurea and UV treatment.
abstract: The effect of human MutY homolog (hMYH) on the activation of checkpoint proteins in response to hydroxyurea (HU) and ultraviolet (UV) treatment was investigated in hMYH-disrupted HEK293 cells. hMYH-disrupted cells decreased the phosphorylation of Chk1 upon HU or UV treatment and increased the phosphorylation of Cdk2 and the amount of Cdc25A, but not Cdc25C. In siMYH-transfected cells, the increased rate of phosphorylated Chk1 upon HU or UV treatment was lower than that in siGFP-transfected cells, meaning that hMYH was involved in the activation mechanism of Chk1 upon DNA damage. The phosphorylation of ataxia telangiectasia and Rad3- related protein (ATR) upon HU or UV treatment was decreased in hMYH-disrupted HEK293 and HaCaT cells. Co-immunoprecipitation experiments showed that hMYH was immunoprecipitated by anti-ATR. These results suggest that hMYH may interact with ATR and function as a mediator of Chk1 phosphorylation in response to DNA damage.
authors: Department of Advanced Technology Fusion, Konkuk University, Seoul, Korea.
authors: Soo-Hyun
authors: SH
authors: Hahm
authors: Jong-Hwa
authors: JH
authors: Park
authors: Sung Il
authors: SI
authors: Ko
authors: You Ri
authors: YR
authors: Lee
authors: In Sik
authors: IS
authors: Chung
authors: Ji Hyung
authors: JH
authors: Chung
authors: Lin-Woo
authors: LW
authors: Kang
authors: Ye Sun
authors: YS
authors: Han