抄録
The structural maintenance of chromosome (SMC), family proteins that plays a central role in chromosome dynamics and stability, is categorized to three groups in eukaryotes: SMC1-3 as a core protein of the cohesins which regulates the chromosome synapsis, SMC2-4 as a core protein of condensins which plays a role in chromosome condensation during miosis and SMC5-6 complex possibly involved in DNA repair and chromosome segregation. Yeast SMC5 or SMC6 mutants showed increased sensitivity to DNA damage-inducing agents such as methyl methanesulfonate (MMS) and hydroxyurea (HU), suggesting the potential involvement in homologous recombination repair and stabilization of replication fork. Moreover, high sensitivity to MMS and ionizing radiation is reported in the mutants of yeast Rad62, non-SMC proteins formed complex with SMC5-6.
To clarify the function of SMC5-6/non-SMC protein complex in higher eukaryotes, we identify human Rad62 gene and analysis the role in a response to radiation damage. Two orthologs of Rad62, Rad62A and Rad62B, were identified when human cDNA was screened. The modification of Rad62A protein was observed after exposure to radiation (IR). We are presently preparing Rad62A knock-down cells to examine the sensitivity to DNA damage agents, such as UV and radiation.
