Involvement of heat shock elements and basal transcription elements in the differential induction of the 70-kDa heat shock protein and its cognate by cadmium chloride in 9L rat brain tumor cells

Abstract

Exposure of 9L rat brain tumor cells to 40-100 microM CdCl2 for 2 h leads to an induction of a wide spectrum of heat shock proteins (HSPs). We have demonstrated that induction of the 70-kDa HSP (HSP70) and enhanced expression of its cognate (HSC70) by cadmium are concentration dependent and that the induction kinetics of these HSP70s are different. The increased synthesis of the HSP70s is accompanied by the increase in hsp70 and hsc70 mRNA levels, indicative of transcriptional regulation of the heat shock genes. Electrophoretic mobility shift assay (EMSA) using probes encompassing heat shock element (HSE), TATA, GC, and CCAAT boxes derived from the promoter regions of the heat shock genes shows distinguished binding patterns between hsp70 and hsc70 genes in both control and cadmium-treated cells. The results indicate that, in addition to the HSEs, the basal transcription elements are important in the regulation of the heat shock genes. The binding patterns of the corresponding transcription factors of these elements are examined by EMSA by using extended promoter fragments from respective heat shock genes with sequential addition of excess oligonucleotides encompassing individual transcription elements. Taken together, our results show that the differential induction of hsp70 and hsc70 involves multiple transcription factors that interact with HSE, TATA, GC, and CCAAT boxes.

Cognate Hsp70 gene is induced during deep larval diapause in the moth Sesamia nonagrioides

“…The primary structure of the Hsp70 genes includes an amino-terminal ATP-binding domain ≈ 45 kDa and a carboxy-terminal substrate binding domain ≈ 25 kDa. Likewise, the inducible and constitutive Hsp70s have common regulatory features and domains (Hung et al ., 1998). Despite these similarities, the expression patterns of these proteins are quite different.…”

Zebrafish HSC70 promoter to express carp muscle-specific creatine kinase for acclimation under cold condition

“…The promoter analysis using Genomatix tools showed that there are four Fkh-domain factor FKHRL1 (FOXO) binding sites. One binding site controled calorie restriction in a mouse model (Murakami 2006); two heat-shock factor 1 (HSF1) binding sites directly contributed to heat-shock response of hsc70 (Park et al 1994); and two CCAAT/enhancer binding protein beta induced different transcription levels by different transcription-factor binding activity (Hung et al 1998;Chang et al 1999). These transcription : pEGFP-C1-CIP; : pEGFP-C1-CIP-M3CK.…”

Cloning, sequencing and expression analysis of cDNA encoding a constitutive heat shock protein 70 (HSC70) in Fenneropenaeus chinensis

“…Some researchers observed that the induction of hsc70 transcription in response to cadmium in rat brain tumor cells [26], electrical shock in mouse brain [27] and heat shock in zebra fish embryo [28], while HSC70 protein level was not affected by heavy metals or heat shock in rainbow trout [29]. The expression of hsc70 in muscle was not affected by heat shock in Fenneropenaeus chinensis.…”