Do mitochondria regulate the heat-shock response in Saccharomyces cerevisiae?
A mild heat shock induces the synthesis of heat-shock proteins (hsps), which protect cells from damage during more extreme heat exposure. The nature of the signals that induce transcription of heat shock-regulated genes remains conjectural. In this work we studied the role of mitochondria in regulating hsps synthesis in Saccharomyces cerevisiae. The results obtained clearly indicate that a mild heat shock elicits a hyperpolarization of the inner mitochondrial membrane and such an event is one of several signals triggering the chain of reactions that activates the expression of the HSP104 gene and probably the expression of other heat shock-regulated genes in S. cerevisiae. The uncouplers or mitochondrial inhibitors which are capable of dissipating the potential on the inner mitochondrial membrane under particular experimental conditions prevent the synthesis of Hsp104 induced by mild heat shock and thus inhibit the development of induced thermotolerance. It is suggested that cAMP-dependent protein kinase A is participating in the mitochondrial regulation of nuclear genes.
Rikhvanov
Eugene G
EG
Siberian Institute of Plant Physiology and Biochemistry, Siberian Division, Russian Academy of Sciences, Lermontov St. 132, Irkutsk 664033, Russia. eugene@sifibr.irk.ru
Varakina
Nina N
NN
Rusaleva
Tatyana M
TM
Rachenko
Elena I
EI
Knorre
Dmitry A
DA
Voinikov
Victor K
VK
D000818:Animals; D019069:Cell Respiration / Q000187:drug effects; D017868:Cyclic AMP-Dependent Protein Kinases; D004272:DNA, Mitochondrial; D015966:Gene Expression Regulation, Fungal; D006360:Heat-Shock Proteins / Q000096:biosynthesis* / Q000235:genetics; D018869:Heat-Shock Response / Q000187:drug effects / Q000502:physiology*; D008564:Membrane Potentials; D008928:Mitochondria / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D017382:Reactive Oxygen Species / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins / Q000096:biosynthesis* / Q000235:genetics; D019810:Sodium Azide / Q000494:pharmacology
D004272:DNA, Mitochondrial; D006360:Heat-Shock Proteins; D017382:Reactive Oxygen Species; D029701:Saccharomyces cerevisiae Proteins; C070972:HsP104 protein, S cerevisiae; D019810:Sodium Azide; D017868:Cyclic AMP-Dependent Protein Kinases