Regulation of HSP70 and HSP28 gene expression: absence of compensatory interactions

• Published in: Molecular and cellular biochemistry 1994-08, Vol.137 (2), p.155-167
• Main Authors: Lee, Y J, Hou, Z Z, Curetty, L, Erdos, G, Stromberg, J S, Carper, S W, Cho, J M, Corry, P M
• Format: Article
• Language: English
• Subjects: Animals; Base Sequence; Blotting, Northern; Blotting, Western; DNA-Binding Proteins - biosynthesis; DNA-Binding Proteins - isolation & purification; Electrophoresis, Gel, Two-Dimensional; Gene Expression Regulation; Heat Shock Transcription Factors; Heat-Shock Proteins - biosynthesis; HSP30 Heat-Shock Proteins; HSP70 Heat-Shock Proteins - biosynthesis; HSP70 Heat-Shock Proteins - isolation & purification; Humans; L Cells (Cell Line); Membrane Proteins - biosynthesis; Mice; Molecular Sequence Data; Oligodeoxyribonucleotides; Promoter Regions, Genetic; Recombinant Proteins - biosynthesis; Recombinant Proteins - isolation & purification; Transcription Factors; Transfection
• ISSN: 0300-8177; 1573-4919
• DOI: 10.1007/BF00944077

We have previously reported the lack of HSP28 gene expression during acute and chronic thermotolerance development in L929 cells (J Cell Physiol 152: 118-125, 1992; Cancer Res 52: 5787, 1992). In contrast to HSP28, an extremely high level of inducible HSP70 synthesis was observed. These results led us to investigate the possibility of compensatory interactions between HSP70 and HSP28. To test the hypothesis, L929 cells were transfected with the human HSP28 gene contained in plasmid pCMV27. Data from Western blot and two-dimensional gel electrophoresis of [3H] leucine and [32P] orthophosphate-labeled proteins showed the synthesis and phosphorylation of HSP28 in transfected cells after heating at 45 degrees C for 10 min. However, the expression of constitutive and inducible HSP70 genes, along with the synthesis of their proteins, was not decreased after heat shock. These results suggest an independent regulation of HSP28 and HSP70 gene expression.