title: cDNA cloning of heat shock protein 90 gene and protein expression pattern in response to heavy metal exposure and thermal stress in planarian Dugesia japonica.
abstract: Heat shock protein 90 (HSP90) is an abundant and highly conserved molecular chaperone, playing important roles in multiple cellular stress responses. The full-length cDNA of planarian Dugesia japonica Hsp90 (designated DjHsp90) was firstly cloned using rapid amplification of cDNA ends (RACE) techniques. It is 2,354 bp, including an open reading frame (ORF) of 2,148 bp encoding a polypeptide of 715 amino acids with all five HSP90 family signatures. We sequenced the ORF sequences from genomic DNA, and found only one intron (48 bp) existed in Djhsp90 gene structure. We used western blot and immunohistochemistry to analyze the expression pattern of DjHsp90 in response to heavy metal exposure and thermal stress at the protein level. Our results show that low doses of heavy metals and elevated culture temperature induced, but high doses of heavy metals and severe heat shock inhibited DjHsp90 expression. In response to heavy metals and thermal stress, DjHsp90-positive cells only appeared in the parenchymal tissue under epidermis cells along the bilateral from head to tail. These positive cells are presumably sensor cells that can detect external environment changes. Our work provides basic data for the study of stress responses in planarians.
authors.affiliation: College of Life Sciences, Henan Normal University, Xinxiang, People's Republic of China.
authors.forename: Ke-Xue
authors.initials: KX
authors.lastname: Ma
authors.forename: Guang-Wen
authors.initials: GW
authors.lastname: Chen
authors.forename: De-Zeng
authors.initials: DZ
authors.lastname: Liu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D016000:Cluster Analysis; D016384:Consensus Sequence; D018076:DNA, Complementary / Q000235:genetics; D040461:Gene Components; D005786:Gene Expression Regulation / Q000187:drug effects; D018841:HSP90 Heat-Shock Proteins / Q000235:genetics* / Q000378:metabolism; D018869:Heat-Shock Response / Q000235:genetics*; D015801:Helminth Proteins / Q000235:genetics* / Q000378:metabolism; D007854:Lead / Q000494:pharmacology*; D008628:Mercury / Q000494:pharmacology*; D008969:Molecular Sequence Data; D010932:Planarians / Q000166:cytology / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic
chemical_list: D018076:DNA, Complementary; D018841:HSP90 Heat-Shock Proteins; D015801:Helminth Proteins; D007854:Lead; D008628:Mercury