Salmonella Wrestles with host SUMO

Dr. C. V. Srikanth and his team, identify novel pathway used by intestinal pathogen, SalmonellaTyphimurium, for its infection and survival. Read his recently published findings: http://mcb.asm.org/content/early/2015/06/16/MCB.00397-15.abstract

In this work the authors have demonstrated a vital role for SUMOylation, a form of Post Translational Modifications (PTMs) in modulating Salmonella infection. The most unexpected finding here was how the pathogen utilized small non-coding RNAs (miRNAs) of the host to fine tune the SUMO status making it suitable for better infection.

Understandably intestinal pathogens, which thrive in harsh environments both inside and outside the host, have evolved sophisticated strategies to achieve instantaneous control over host functions. The work by Dr. C. V. Srikanth and his team is the first report of modulation by intestinal pathogen Salmonella enterica serovar Typhimurium (ST) of host SUMOylation, a pathway central to all fundamental cellular processes. Using a multipronged approach, they demonstrated that ST infection led to a dynamic SUMO-conjugated proteome alteration. The survival of ST was dependent on SUMO status as revealed by reduced infection andSalmonella induced filaments (SIFs) in SUMO-upregulated cells. ST dependent SUMO modulation was seen as a result of depletion of crucial SUMO-pathway enzymes Ubc-9 and PIAS1, both at the protein and transcript levels. Mechanistically, depletion of Ubc-9 relied on upregulation of small non-coding RNA miR30c and miR30e during ST infection. This was necessary and sufficient for both down-modulation of Ubc-9 and a successful infection. Taken together this work demonstrates a novel strategy of pathogen mediated perturbation of host SUMOylation, an integral mechanism underlying ST infection and intracellular survival.

Full paper can be found at: http://www.wellcomedbt.org/uploads/files/Mol.%20Cell.%20Biol.-2015-Verma-MCB.00397-15.pdf