VUV-CD measurements of histone H2A-H2B proteins; Secondary structural alterations induced by DNA damage responses

ヒストンH2A-H2BのVUV-CD測定; DNA損傷応答に誘起される二次構造変化

泉 雄大

Izumi, Yudai

DNA wraps around core histone proteins composed of several subunits named as H2A, H2B, H3, and H4 in eukaryotic nuclei. It has been gradually recognized that chemical modifications of histones play important roles in DNA repair processes. However, the dynamics of histones during DNA damage repair processes is not explained completely. In this work, we confirmed whether the structural alterations of histone H2A and H2B (H2A-H2B) are induced by DNA damage responses using vacuum ultraviolet circular dichroism (VUV-CD) spectroscopy. The VUV-CD spectra showed that -helix content of H2A-H2B extracted from X-irradiated human cells relatively increased comparing to that from unirradiated cells (38.3 46.5%). Since X-ray damage to H2A-H2B itself induces decrement of -helix structures, we concluded that the structural alterations were induced as a results of DNA damage responses, such as DNA damage repair processes.