RRC ID 16104
著者 Kihara F, Niimi T, Yamashita O, Yaginuma T.
タイトル Heat shock factor binds to heat shock elements upstream of heat shock protein 70a and Samui genes to confer transcriptional activity in Bombyx mori diapause eggs exposed to 5°C.
ジャーナル Insect Biochem Mol Biol
Abstract To understand the molecular mechanisms of how 5°C-incubation activates mRNA expression of Hsp70a and Samui genes in Bombyx mori diapause eggs, we first searched the 5'-upstream regions of the Hsp70a and Samui genes for heat shock elements (HSEs) and found two regions [Hsp70aHSE-1 (-95 to -58) and -2 (-145 to -121), and SamuiHSE-1 (-84 to -55) and -2 (-304 to -290)] corresponding to HSEs (repeats of nGAAn and/or nTTCn). We cloned four cDNAs encoding heat shock factor (HSF)-a2 (627 amino acids), -b (685 aa), -c (682 aa) and -d (705 aa), which were produced by alternative splicing. When we exposed diapause eggs to 5°C beginning at 2 day post-oviposition to break diapause, HSFd mRNA only increased after chilling for 6-8 days, a pattern very similar to those of Hsp70a and Samui mRNAs. To examine further whether HSFd binds to the respective HSEs, we carried out a gel shift assay using HSFd protein expressed in a cell-free system and the isolated HSEs; migration of the respective digoxigenin(DIG)-labeled HSE-1 and -2 of Hsp70a and Samui was retarded by addition of HSFd; the retarded bands disappeared after addition of the corresponding unlabeled HSE-1 and -2 as competitors, but were not affected by addition of the respective mutated unlabeled HSE-1 and -2. These results indicated that HSFd protein binds to the respective HSEs and may activate mRNA expression of Hsp70a and Samui genes upon exposure of diapause eggs to 5°C.
巻・号 41(11)
ページ 843-51
公開日 2011-11-1
DOI 10.1016/j.ibmb.2011.06.006
PII S0965-1748(11)00142-1
PMID 21782023
MeSH 5' Flanking Region Amino Acid Sequence Animals Base Sequence Bombyx / embryology Bombyx / genetics Bombyx / metabolism* Cell-Free System Cloning, Molecular Female HSP70 Heat-Shock Proteins / genetics HSP70 Heat-Shock Proteins / metabolism* Heat-Shock Proteins / genetics Heat-Shock Proteins / metabolism* Insect Proteins / genetics Insect Proteins / metabolism* Male Molecular Sequence Data Ovum / metabolism* RNA, Messenger / metabolism
IF 3.827
引用数 6
WOS 分野 ENTOMOLOGY BIOCHEMISTRY & MOLECULAR BIOLOGY
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