Pleurotus sajor-caju HSP100 complements a thermotolerance defect in hsp104 mutant Saccharomyces cerevisiae.
A putative Hsp100 gene was cloned from the fungus Pleurotus sajor-caju. mRNA expression studies demonstrated that this gene (designated PsHsp100) is highly induced by high temperature,induced less strongly by exposure to ethanol, and not induced by drought or salinity. Heat shock induction is detectable at 37 degrees C and reaches a maximum level at 42 degrees C. PsHsp100 mRNA levels sharply increased within 15 min of exposure to high temperature, and reached a maximum expression level at 2 h that was maintained for several hours. These results indicate that PsHsp100 could work at an early step in thermotolerance. To examine its function, PsHsp100 was transformed into a temperature-sensitive hsp104 deletion mutant Saccharomycetes cerivisiae strain to test the hypothesis that PsHSP100 is an protein that functions in thermotolerance. Overexpression of PsHSP100 complemented the thermotolerance defect of the hsp104 mutant yeast, allowing them being survive even at 50 degree C for 4 h. These results indicate that PsHSP100 protein is functional as an HSP100 in yeast and could play and important role in thermotolerance in P. sajor-caju.
Lee
Jin-Ohk
JO
National Institute of Agricultural Biotechnology, Rural Development Administration, Suwon 441-707, Korea.
Jeong
Mi-Jeong
MJ
Kwon
Tack-Ryun
TR
Lee
Seung-Kon
SK
Byun
Myung-Ok
MO
Chung
Ill-Min
IM
Park
Soo-Chul
SC
D000595:Amino Acid Sequence; D001483:Base Sequence; D005656:Fungal Proteins / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation; D005816:Genetic Complementation Test; D006360:Heat-Shock Proteins / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D030781:Organisms, Genetically Modified; D010802:Phylogeny; D020076:Pleurotus / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment
D005656:Fungal Proteins; D006360:Heat-Shock Proteins; D012333:RNA, Messenger; D029701:Saccharomyces cerevisiae Proteins; C070972:HsP104 protein, S cerevisiae