2011.03.18,Professors Yao Xuebiao and Professor Rao Zihe Published a paper in Journal of Biological Chemistry

  • 2011.03.18,Professors Yao Xuebiao and Rao Zihe Journal of Biological Chemistry published a paper entitled “Structure-Functional Analyses of CRHSP-24 Plasticity and Dynamics in Oxidative Stress Response” in Journal of Biological Chemistry
    Author:Hou Hai、Wang fengsong、Zhang wenchi、Wang Dongmei、Li Xuemei、Mark Bartlam、Yao Xuebiao、 Rao Zihein 
    Abstract

    The cold shock domain (CSD) is an evolutionarily conserved nucleic acid binding domain that exhibits binding activity to RNA, ssDNA, and dsDNA. Mammalian CRHSP-24 contains CSD, but its structure-functional relationship has remained elusive. Here we report the crystal structure of human CRHSP-24 and characterization of the molecular trafficking of CRHSP-24 between stress granules and processing bodies in response to oxidative stress. The structure of CRHSP-24 determined by single-wavelength anomalous dispersion exhibits an α-helix and a compact β-barrel formed by five curved anti-parallel β strands. Ligand binding activity of the CSD is orchestrated by residues Ser41 to Leu43. Interestingly, a phosphomimetic S41D mutant abolishes the ssDNA binding in vitro and causes CRHSP-24 liberated from stress granules in vivo without apparent alternation of its localization to the processing bodies. This new class of phosphorylation-regulated interaction between the CSD and nucleic acids is unique in stress granule plasticity. Importantly, the association of CRHSP-24 with stress granules is blocked by PP4/PP2A inhibitor calyculin A as PP2A catalyzes the dephosphorylation of Ser41 of CRHSP-24. Therefore, we speculate that CRHSP-24 participates in oxidative stress response via a dynamic and temporal association between stress granules and processing bodies.

     

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