A novel G1-specific enhancer identified in the human heat shock protein 70 gene.

Taira Takahiro; Narita Tomoko; Iguchi-Ariga Sanae M. M.; Ariga Hiroyoshi

Title	en A novel G1-specific enhancer identified in the human heat shock protein 70 gene.
Creator	en Taira, Takahiro NRID 1000070197036 en Narita, Tomoko en Iguchi-Ariga, Sanae M. M. NRID 1000090184283 en Ariga, Hiroyoshi NRID 1000020143505
Accessrights	open access
Subject	MeSH en 3T3 Cells MeSH en Animals MeSH en Cell Cycle MeSH en Cloning, Molecular MeSH en Cyclins/biosynthesis MeSH en Cyclins/genetics MeSH en DNA Replication MeSH en Enhancer Elements, Genetic MeSH en G1 Phase MeSH en HSP70 Heat-Shock Proteins/biosynthesis MeSH en HSP70 Heat-Shock Proteins/genetics MeSH en Humans MeSH en Kinetics MeSH en L Cells (Cell Line) MeSH en Luciferases/biosynthesis MeSH en Mice MeSH en Plasmids MeSH en Polymerase Chain Reaction MeSH en Proliferating Cell Nuclear Antigen/biosynthesis MeSH en Proliferating Cell Nuclear Antigen/genetics MeSH en Promoter Regions, Genetic MeSH en Recombinant Fusion Proteins/biosynthesis MeSH en S Phase MeSH en Transcription, Genetic NDC 499
Description	Abstract en Expression of the human heat shock protein 70 gene (hsp70) is induced by various kinds of stress and by oncogenes. In the absence of stress, hsp70 is mainly expressed in the G1and S phases of the cell cycle, but the elements contributing to cell cycle-dependent expression from the hsp70 promoter remain elusive. We have previously reported that two elements, named HSP-MYCA and HSP-MYCB, located approximately 200 bp upstream (-200) from the transcription start site (+1) of human hsp70, are important for initiation of DNA replication at the hsp70 locus. In this report we examine the effect of these two elements on transcriptional activity from the hsp70 promoter, especially in terms of cell cycle-dependent expression. Various segments of the hsp70 promoter region (up to -300) were linked to the luciferase gene and the constructs were transfected into mouse L cells to examine their transcriptional activity. A strong enhancer activity was defined in the HSP-MYCB element, but not in HSP-MYCA. Mutations introduced within HSP-MYCB abolished the transcriptional activation. In synchronized cells, pHB-Luc (a luciferase construct containing approximately 2.4 kb of the hsp70 promoter region) as well as endogenous hsp70 showed two peaks of expression; one in G1 and the other in the S phase. Site-directed mutagenesis of HSP-MYCB in pHB-Luc abolished the expression peak in G1, but not that in the S phase. To test promoter specificity, wild-type and mutant HSP-MYCB elements were then linked to the luciferase gene in combination with the hsp70 , the cyclin A or the PCNA promoter. Both in transient experiments and established cell lines, a strong peak of expression in mid-G1phase was observed with all the constructs containing wild-type HSP-MYCB, but not with the constructs containing the mutant sequence. These results suggest that the HSP-MYCB sequence is a G1-specific enhancer and is responsible for cell cycle-dependent expression of hsp70.
Publisher	en Oxford University Press
Date	Issued1997-05-15
Language	eng
Resource Type	journal article
Version Type	VoR
Identifier	HDL http://hdl.handle.net/2115/53977
Relation	isIdenticalTo DOI https://doi.org/10.1093/nar/25.10.1975 PMID 9115365
Journal	PISSN 0305-1048 en Nucleic acids research Volume Number25 Issue Number10 Page Start1975 Page End1983
File	fulltext 79_Ariga_1997_Nucleic_Acids_Res.pdf 222.46 KB (application/pdf) Issued1997-05-15
Oaidate	2023-07-26