title: High mobility group protein DSP1 negatively regulates HSP70 transcription in Crassostrea hongkongensis.
abstract: HSP70 acts mostly as a molecular chaperone and plays important roles in facilitating the folding of nascent peptides as well as the refolding or degradation of the denatured proteins. Under stressed conditions, the expression level of HSP70 is upregulated significantly and rapidly, as is known to be achieved by various regulatory factors controlling the transcriptional level. In this study, a high mobility group protein DSP1 was identified by DNA-affinity purification from the nuclear extracts of Crassostrea hongkongensis using the ChHSP70 promoter as a bait. The specific interaction between the prokaryotically expressed ChDSP1 and the FITC-labeled ChHSP70 promoter was confirmed by EMSA analysis. ChDSP1 was shown to negatively regulate ChHSP70 promoter expression by Luciferase Reporter Assay in the heterologous HEK293T cells. Both ChHSP70 and ChDSP1 transcriptions were induced by either thermal or CdCl2 stress, while the accumulated expression peaks of ChDSP1 were always slightly delayed when compared with that of ChHSP70. This indicates that ChDSP1 is involved, very likely to exert its suppressive role, in the recovery of the ChHSP70 expression from the induced level to its original state. This study is the first to report negative regulator of HSP70 gene transcription, and provides novel insights into the mechanisms controlling heat shock protein expression.
authors.affiliation: Institute of Hydrobiology, Department of Ecology, Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, Jinan University, Guangzhou 510632, PR China.
authors.forename: Zongyu
authors.initials: Z
authors.lastname: Miao
authors.affiliation: Institute of Hydrobiology, Department of Ecology, Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, Jinan University, Guangzhou 510632, PR China.
authors.forename: Delin
authors.initials: D
authors.lastname: Xu
authors.affiliation: Institute of Hydrobiology, Department of Ecology, Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, Jinan University, Guangzhou 510632, PR China.
authors.forename: Miao
authors.initials: M
authors.lastname: Cui
authors.affiliation: Institute of Hydrobiology, Department of Ecology, Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, Jinan University, Guangzhou 510632, PR China. Electronic address: zhangqzdr@126.com.
authors.forename: Qizhong
authors.initials: Q
authors.lastname: Zhang
mesh_terms: D000818:Animals; D049896:Crassostrea / Q000201:enzymology*; D029721:Drosophila Proteins / Q000378:metabolism*; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology*; D050884:HSP72 Heat-Shock Proteins / Q000378:metabolism*; D006609:High Mobility Group Proteins / Q000378:metabolism*; D015533:Transcriptional Activation / Q000502:physiology*
chemical_list: C104348:DSP1 protein, Drosophila; D029721:Drosophila Proteins; D050884:HSP72 Heat-Shock Proteins; D006609:High Mobility Group Proteins
keywords: Crassostrea hongkongensis; DSP1; HSP70; Negative regulator; Transcription