IBR   13079
INSTITUTO DE BIOLOGIA MOLECULAR Y CELULAR DE ROSARIO
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Lipid regulation of DesK, the Bacillus subtillis thermosensor
Autor/es:
MARTÍN, M.; DE MENDOZA, D.
Reunión:
Encuentro; 3rd Latin American Protein Society Meeting; 2010
Resumen:
The Bacillus subtilis DesK histidine kinase (HK) is an integral membrane thermosensor involved in a regulatory circuit which controls the physical state of membrane lipids1. DesK regulates the phosphorylation state of its cognate response regulator, DesR, which in turn induces the expression of the cold shock-inducible fatty acid desaturase encoded by the des gene2. Experimental evidence suggests that DesK detects environmental temperature changes through its hydrophobic N-terminal domain composed of five transmembrane regions capable of sensing membrane fluidity as the stimulus of DesK-mediated des expression 2-5. In the pursuit of biochemical and structural approaches to study lipid fluidity-dependent DesK thermosensing, we have developed and optimized a one-step protocol, based in an Escherichia coli in vitro transcription–translation system, for routinely purifying large quantities of soluble and liposome integrated functional DesK6. As expected, the cold signal regulates the autokinase and phosphatase activities of DesK integrated in liposomes of E. coli phospholipids in opposite directions7. As the interplay between the protein helices and their lipid environment is a key factor in understanding the structural and functional properties of this HK, in this work, we studied the effect of phospholipids headgroup and fatty acyl chains lengths over DesK activity. As a consequence, we would gain insight into the mechanism by which this sensor protein adjusts its signaling state in response to changes in the biophysical properties of the membrane