Inhibition of lipid biosynthesis induces the expression of the pspA gene

1 Institut für Mikrobiologie, Karl-Franzens-Universität Graz, Universitätsplatz 2, A-8010 Graz, Austria 2 Sandoz Forschungsinstitut GesmbH, Brunnerstraße 59, A-1235 Vienna, Austria ABSTRACT Treatment of Escherichia coli with diazaborine strongly induces the synthesis of a 28 kDa protein which is associated with the cytoplasmic membrane. The partial amino acid sequence proved that this protein is identical to the phage shock protein PspA. The kinetics of the expression of the pspA gene were determined in an E. coli strain which carried a pspA-lacZ fusion in the chromosome. PspA synthesis is independent of the growth phase. It is, however, strongly induced when fatty acid biosynthesis is inhibited by diazaborine or cerulenin. Treatment with either compound also causes dose-dependent inhibition of phospholipid biosynthesis whose degree correlates with the induction of PspA. Another cause of induction of PspA synthesis is treatment of E. coli with globomycin, which is an inhibitor of the processing of lipoproteins. Author for correspondence: Friederike Turnowsky. Tel: +43 316 3805620. Fax: +43 316 381548. Keywords: Escherichia coli , pspA gene, lipid synthesis, diazaborine, globomycin