A novel Arabidopsis gene required for ethanol tolerance is conserved among plants and archaea.
A novel ethanol-hypersensitive mutant, gek1, of Arabidopsis shows 10-100 times greater sensitivity to ethanol compared to the wild type, while it grows normally in the absence of ethanol, and responds normally to other alcohols and to environmental stresses such as heat shock and high salinity. Mapping of the gek1 locus indicated it is a previously unreported locus. In order to address the GEK1 function, we identified the GEK1 gene by means of map-based cloning. The GEK1 gene encodes a novel protein without any known functional motifs. Transgenic Arabidopsis plants overexpressing GEK1 displayed an enhanced tolerance to ethanol and acetaldehyde, suggesting that GEK1 is directly involved in the tolerance to those chemicals. By contrast, expression of GEK1 in E. coli and yeasts did not increase their tolerance to ethanol or acetaldehyde. Interestingly, a similarity search revealed that GEK1-related genes are conserved only in plants and archaea. These results might suggest that plants, and presumably archaea, have a novel mechanism for protection from acetaldehyde toxicity.
Fujishige
Naoko
N
Graduate School of Integrated Science, Yokohama City University, Yokohama, 230-0045 Japan.
Nishimura
Noriyuki
N
Iuchi
Satoshi
S
Kunii
Takanori
T
Shinozaki
Kazuo
K
Hirayama
Takashi
T
D000079:Acetaldehyde / Q000378:metabolism / Q000633:toxicity; D020816:Amino Acid Motifs / Q000235:genetics; D000595:Amino Acid Sequence / Q000235:genetics; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D001105:Archaea / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence / Q000235:genetics; D017124:Conserved Sequence / Q000235:genetics; D018076:DNA, Complementary / Q000032:analysis / Q000235:genetics; D004361:Drug Tolerance / Q000235:genetics*; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D000431:Ethanol / Q000378:metabolism* / Q000633:toxicity; D019143:Evolution, Molecular; D018506:Gene Expression Regulation, Plant / Q000235:genetics; D008969:Molecular Sequence Data; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D015003:Yeasts / Q000187:drug effects / Q000235:genetics / Q000378:metabolism
D029681:Arabidopsis Proteins; D018076:DNA, Complementary; C490038:GEK1 protein, Arabidopsis; D000431:Ethanol; D000079:Acetaldehyde