Formation of nuclear HSF1 granules varies depending on stress stimuli

Cell Stress Chaperones. 2000 Jul;5(3):219-28. doi: 10.1379/1466-1268(2000)005<0219:fonhgv>2.0.co;2.

Abstract

In concert with the stress-induced activation of human heat shock factor 1 (HSF1), the factor becomes inducibly phosphorylated and accumulates into nuclear granules. To date, these processes are not fully understood. Here, we show that although stress caused by the proteasome inhibitors MG132 and clasto-lactacystine beta-lactone induces the expression of Hsp70, the formation of HSF1 granules is affected differently in comparison to heat shock. Furthermore, proteasome inhibition increases serine phosphorylation on HSF1, but to a lesser extent than heat stress. Our results suggest that, depending on the type of stress stimulus, the multiple events associated with HSF1 activation might be affected differently.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Blotting, Western
  • Cell Nucleus Structures / metabolism*
  • Cysteine Endopeptidases / drug effects*
  • Cysteine Endopeptidases / metabolism
  • Cysteine Proteinase Inhibitors / pharmacology
  • DNA-Binding Proteins / metabolism*
  • HSP70 Heat-Shock Proteins / genetics
  • HSP70 Heat-Shock Proteins / metabolism
  • HeLa Cells
  • Heat Shock Transcription Factors
  • Heat-Shock Proteins / metabolism*
  • Heat-Shock Response*
  • Humans
  • K562 Cells
  • Lactones / pharmacology
  • Leupeptins / pharmacology
  • Microscopy, Fluorescence
  • Multienzyme Complexes / antagonists & inhibitors*
  • Multienzyme Complexes / drug effects*
  • Multienzyme Complexes / metabolism
  • Phosphorylation / drug effects
  • Promoter Regions, Genetic / genetics
  • Proteasome Endopeptidase Complex
  • Recombinant Proteins / immunology
  • Recombinant Proteins / metabolism
  • Transcription Factors

Substances

  • Cysteine Proteinase Inhibitors
  • DNA-Binding Proteins
  • HSF1 protein, human
  • HSP70 Heat-Shock Proteins
  • Heat Shock Transcription Factors
  • Heat-Shock Proteins
  • Lactones
  • Leupeptins
  • Multienzyme Complexes
  • Recombinant Proteins
  • Transcription Factors
  • clasto-lactacystin beta-lactone
  • Cysteine Endopeptidases
  • Proteasome Endopeptidase Complex
  • benzyloxycarbonylleucyl-leucyl-leucine aldehyde