RNA-processing proteins in halophilic archaea and their role in mRNA-degradation

• Applicant: Professorin Dr. Gabriele Klug
• Subject Area: Metabolism, Biochemistry and Genetics of Microorganisms
• Term: from 2003 to 2007
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5410689

mRNA-processing in bacteria and eukarya is a highly-ordered process which contributes to the regulation of gene expression. We have previously shown that as well salt concentration as growth phase influence the stability of some gvp-transcripts for gas vesicle synthesis but not of others in Haloferax. This implies that mRNA-processing contributes to regulated gene expression in archaea. We now want to perform a global analysis of mRNA-stabilities and their dependence of salt concentration and growth phase in Halobacterium salinarum by using microarrays. Furthermore we will apply three different approaches for the identification of mRNA-processing enzymes: 1) overexpression and characterization of H. salinarum proteins which are homologs to bacterial or eukaryal proteins with RNase or helicase function, 2) classical purification and characterization of RNA-processing activities from H. salinarum, 3) search for interaction partners of the identified proteins, since as well in bacteria as in eukarya large multi protein complexes are involved in mRNA turn-over. We will contruct knock-out mutant strains which lack such RNA-processing proteins and will apply the microarray analysis to test the effect of the mutation on global mRNA-stability at single gene resolution and will study the effect on the degradation of few selected transcripts in more detail. It will be of special interest to see how the RNA-degrading machinery has adapted to high salt concentrations.

• DFG Programme: Research Grants