Effects of L protein on MreB and cell lysis

Abstract

The MS2 bacteriophage is a single-stranded, positive-strand RNA virus that contains four genes: mat, coat, rep, and L. The L protein is responsible for cell lysis, although relatively little is known about its mode of action. Unlike other viral lysis proteins, which inhibit cell wall synthesis at the division site causing midcell blebs, L protein appears to cause lysis at random cellular locations, as seen by bleb formation throughout the cell. We hypothesized that L protein works with MreB, an essential protein for cell wall synthesis, which is localized throughout the cell body. We seek to identify how L protein affects MreB by possibly: causing the mislocalization of MreB at specific sites of lysis, activating a section of MreB to form a hotspot for cell wall synthesis, or deactivating a section of the MreB pool, causing cell defects. To begin to determine which mechanism is correct, we will measure the localization of MreB in cells undergoing lysis to see if there is a correlation between MreB localization and L protein induced lysis. We will then examine if there is a direct interaction between L protein and MreB using biomolecular fluorescent complementation. Learning how L protein lyses cells will provide us with a better understanding of single gene lysis, which can be applied to phage therapy to kill disease causing bacteria and to effectively prevent bacteriophages from killing helpful bacteria that assist in preventing disease or are important for industrial purposes.