title: Structure-functional analyses of CRHSP-24 plasticity and dynamics in oxidative stress response.
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 Ser(41) to Leu(43). 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 Ser(41) 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.
authors.affiliation: National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Hai
authors.initials: H
authors.lastname: Hou
authors.forename: Fengsong
authors.initials: F
authors.lastname: Wang
authors.forename: Wenchi
authors.initials: W
authors.lastname: Zhang
authors.forename: Dongmei
authors.initials: D
authors.lastname: Wang
authors.forename: Xuemei
authors.initials: X
authors.lastname: Li
authors.forename: Mark
authors.initials: M
authors.lastname: Bartlam
authors.forename: Xuebiao
authors.initials: X
authors.lastname: Yao
authors.forename: Zihe
authors.initials: Z
authors.lastname: Rao
mesh_terms: D019943:Amino Acid Substitution; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006367:HeLa Cells; D006801:Humans; D008387:Marine Toxins; D020125:Mutation, Missense; D010080:Oxazoles / Q000494:pharmacology; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology*; D010749:Phosphoprotein Phosphatases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D010750:Phosphoproteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D054648:Protein Phosphatase 2 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D017433:Protein Structure, Secondary; D013329:Structure-Activity Relationship; D014157:Transcription Factors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
chemical_list: C114342:CARHSP1 protein, human; D004268:DNA-Binding Proteins; D004791:Enzyme Inhibitors; D008387:Marine Toxins; D010080:Oxazoles; D010750:Phosphoproteins; D014157:Transcription Factors; C059041:calyculin A; D010749:Phosphoprotein Phosphatases; D054648:Protein Phosphatase 2; C080406:protein phosphatase 4