Molecular basis of thermosensing: a two-component signal transduction thermometer in Bacillus subtilis.
Both prokaryotes and eukaryotes respond to a decrease in temperature with the expression of a specific subset of proteins. Although a large body of information concerning cold shock-induced genes has been gathered, studies on temperature regulation have not clearly identified the key regulatory factor(s) responsible for thermosensing and signal transduction at low temperatures. Here we identified a two-component signal transduction system composed of a sensor kinase, DesK, and a response regulator, DesR, responsible for cold induction of the des gene coding for the Delta5-lipid desaturase from Bacillus subtilis. We found that DesR binds to a DNA sequence extending from position -28 to -77 relative to the start site of the temperature-regulated des gene. We show further that unsaturated fatty acids (UFAs), the products of the Delta5-desaturase, act as negative signalling molecules of des transcription. Thus, a regulatory loop composed of the DesK-DesR two-component signal transduction system and UFAs provides a novel mechanism for the control of gene expression at low temperatures.
Aguilar
P S
PS
Instituto de Biología Molecular y Celular de Rosario (IBR) and Departamento de Microbiología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, 2000-Rosario, Argentina.
Hernandez-Arriaga
A M
AM
Cybulski
L E
LE
Erazo
A C
AC
de Mendoza
D
D
D019677:Artificial Gene Fusion; D001412:Bacillus subtilis / Q000201:enzymology* / Q000235:genetics / Q000502:physiology; D001483:Base Sequence; D003080:Cold Temperature; D004269:DNA, Bacterial / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000502:physiology*; D044943:Fatty Acid Desaturases / Q000235:genetics*; D005231:Fatty Acids, Unsaturated / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D015971:Gene Expression Regulation, Enzymologic; D005798:Genes, Bacterial; D000071677:Histidine Kinase; D007763:Lac Operon; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009363:Neoplasm Proteins; D009687:Nuclear Proteins / Q000502:physiology*; D009876:Operon; D011401:Promoter Regions, Genetic; D011494:Protein Kinases / Q000235:genetics* / Q000378:metabolism; D012329:RNA, Bacterial / Q000096:biosynthesis; D012333:RNA, Messenger / Q000096:biosynthesis; D012097:Repressor Proteins; D015398:Signal Transduction / Q000502:physiology*; D014157:Transcription Factors; D015533:Transcriptional Activation; D001616:beta-Galactosidase / Q000235:genetics / Q000378:metabolism
D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D005231:Fatty Acids, Unsaturated; D009363:Neoplasm Proteins; D009687:Nuclear Proteins; D012329:RNA, Bacterial; D012333:RNA, Messenger; D012097:Repressor Proteins; C108387:TRPS1 protein, human; D014157:Transcription Factors; D044943:Fatty Acid Desaturases; D011494:Protein Kinases; D000071677:Histidine Kinase; D001616:beta-Galactosidase