title: Molecular mechanisms of low temperature sensing bacteria.
abstract: Both prokaryotes and eukaryotes respond to a decrease in temperature with the expression of a specific subset of proteins. We are investigating how Bacillus subtilis cells sense and transduce low-temperature signals to adjust its gene expression. One important step has been accomplished in the dissection of a novel pathway for the adjustment of unsaturated fatty acid synthesis in B.subtilis, termed the Des pathway. It responds to a decrease in growth temperature by enhancing the expression of the des gene, coding for an acyl-lipid desaturase. The Des pathway is uniquely and stringently regulated by a tw-component system composed of a membrane-associated kinase, DesK, and a soluble transcriptional activator, DesR. The temperature sensing ability of the DesK protein is regulated by the extent of disorder within the membrane lipid bilayer. In this work, we present the mechanism by which the sensor protein DesK controls the signal decay of its cognate partner, DesR, and how this response regulator activates transcription of its target promoter. The results of these analysis will be presented and discussed in the context of transcriptional regulation of membrane fluidity homeostasis.
authors.affiliation: Institute of Molecular and Cellular Biology of Rosario, CONICET- National Univesity of Rosario, Suipacha521, S2002LKR Rosario, Argentina.
authors.forename: María C
authors.initials: MC
authors.lastname: Mansilla
authors.forename: Daniela
authors.initials: D
authors.lastname: Albanesi
authors.forename: Larisa E
authors.initials: LE
authors.lastname: Cybulski
authors.forename: Diego
authors.initials: D
authors.lastname: de Mendoza
mesh_terms: D001412:Bacillus subtilis / Q000502:physiology*; D003080:Cold Temperature; D008560:Membrane Fluidity / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology*