Interaction of bacterial actin-like proteins with the cell membrane

• Applicant: Professor Dr. Peter Graumann
• Subject Area: Metabolism, Biochemistry and Genetics of Microorganisms
• Term: from 2008 to 2015
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 43311986

Many prokaryotic cells contain a homolog of actin, called MreB, which shares many conserved properties with actin, and is essential for cell shape maintenance and viability in many bacteria. We have found that it localizes as dynamic helical filaments underneath the cell membrane, together with its two paralogs, Mbl and MreBH. MreB and Mbl interact with two membrane proteins, MreC and RodA, involved in cell shape maintenance, as well as with cytosolic proteins, many of which have an enzymatic function. MreB also interacts with translation factor EF-Tu along the helical tracks, and EF-Tu is also important for cell shape maintenance, showing that EF-Tu serves a dual role in a bacterial cell. EF-Tu shows a similar spectrum of interactions as MreB, suggesting that both proteins set up an interaction network underneath the bacterial cell membrane. Within the FOR, we will search for further evidence for this network and will investigate its role in bacterial physiology. We will also study in detail how MreB and Mbl direct the positioning of membrane proteins, which is the case for RodA, whose function in cell morphology we have begun to study and want to continue to elucidate, amongst others by determining its 3D structure. We will also study the function of membrane protein RodZ, which affects cell shape in an unknown manner in many bacteria.

• DFG Programme: Research Units
• Subproject of: FOR 929: Dynamics of Bacterial Membrane Proteins
• International Connection: France
• Participating Persons: Dr. Isabelle Schalk; Dr. Barbara Waidner