Thermal regulation of membrane lipid fluidity by a two-component system in Bacillus subtilis

BREDESTON, LUIS M.; MARCIANO, DANIELA; ALBANESI, DANIELA; DE MENDOZA, DIEGO; DELFINO, JOSÉ M.

BIOCHEMISTRY AND MOLECULAR BIOLOGY EDUCATION

JOHN WILEY & SONS INC

Lugar: Oxford; Año: 2011 vol. 39 p. 362 - 366

1470-8175

This article describes a simple and robust laboratory exercise on the regulation of membrane unsaturated fatty acid composition in bacteria by a decrease in growth temperature. We take advantage of the well characterized Des pathway of Bacillus subtilis, composed of a D5-desaturase (encoded by the des gene) and the canonical two-component system DesK-DesR, to study the transcriptional regulation of des during cold shock. Students analyze the expression of a reporter transcriptional fusion between the des promoter and the bacterial lacZ gene in a wild-type B. subtilis strain and in des or desK-desR mutants grown under different culture conditions. Measurements of beta-galactosidase activity allow them to investigate how the Des pathway works and to assess the role of each component of this regulatory system.