Identifying Molecular and Biophysical Components of the Switch that Allows a Membrane Thermosensor to alternate between Kinase and Phosphatase States

CYBULSKI LARISA; JOOST BALLERING; DE MENDOZA DIEGO

Encuentro; Annual Dutch Meeting on Molecular and Cellular Biophysics; 2011

The histidine kinase DesK is a five-pass transmembrane thermosensor that regulates membrane fluidity in B. subtilis. Recently we discovered that an engineered hybrid with a single transmembrane segment (TMS) fully retains the activity of full-length DesK [1]. Using biochemical and genetic studies we showed that the lipid-water interface of TMS contains a boundary-sensitive motif, of which the hydration level controls sensing and transmission activity. We are now elucidating the molecular mechanism of sensing by using biophysical approaches to study synthetic peptides corresponding to transmembrane segments of functional and non-functional mutants, incorporated in different synthetic bilayers.