Involvement of Arabidopsis ROF2 (FKBP65) in thermotolerance.
The ROF2 (FKBP65) is a heat stress protein which belongs to the FK506 Binding Protein (FKBP) family. It is homologous to ROF1 (FKBP62) which was recently shown to be involved in long term acquired thermotolerance by its interaction with HSP90.1 and modulation of the heat shock transcription factor HsfA2. In this study, we have demonstrated that ROF2 participates in long term acquired thermolerance, its mode of action being different from ROF1. In the absence of ROF2, the small heat shock proteins were highly expressed and the plants were resistant to heat stress, opposite to the effect observed in the absence of ROF1. It was further demonstrated that ROF2 transcription is modulated by HsfA2 which is also essential for keeping high levels of ROF2 during recovery from heat stress. ROF2 localization to the nucleus was observed several hours after heat stress exposure and its translocation to the nucleus was independent from the presence of HSP90.1 or HsfA2. ROF2 has been shown to interact with ROF1, to form heterodimers and it is suggested that via this interaction it can join the complex ROF1-HSP90.1- HsfA2. Transient expression of ROF2 together with ROF1 repressed transcription of small HSPs. A model describing the mode of action of ROF2 as a heat stress modulator which functions in negative feedback regulation of HsfA2 is proposed.
Meiri
David
D
Department of Plant Sciences, Tel Aviv University, 69978, Tel Aviv, Israel.
Tazat
Keren
K
Cohen-Peer
Reut
R
Farchi-Pisanty
Odelia
O
Aviezer-Hagai
Keren
K
Avni
Adi
A
Breiman
Adina
A
D017360:Arabidopsis / Q000235:genetics / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D015153:Blotting, Western; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D004591:Electrophoresis, Polyacrylamide Gel; D005470:Fluorometry; D018506:Gene Expression Regulation, Plant / Q000235:genetics / Q000502:physiology*; D000076249:Heat Shock Transcription Factors; D006360:Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D006358:Hot Temperature; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D022021:Tacrolimus Binding Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D020798:Two-Hybrid System Techniques
D029681:Arabidopsis Proteins; D004268:DNA-Binding Proteins; C000620134:HSFA2 protein, Arabidopsis; D000076249:Heat Shock Transcription Factors; D006360:Heat-Shock Proteins; D010940:Plant Proteins; C102151:ROF1 protein, Arabidopsis; D014157:Transcription Factors; D022021:Tacrolimus Binding Proteins