Let’s Communicate – Linking Bacterial Quorum Sensing with Stress Response in Saccharomyces Cerevisiae

Antonia Delago, Chemistry, Ben Gurion University of the Negev, Beer Sheva, Israel

Quorum sensing (QS) is a concentration dependent cellular signaling mechanism employed by most bacteria and some fungi. In the past, research on QS focused mainly on its role as an intraspecific signaling pathway that regulates certain behaviors and phenotypes. However, in recent years more studies have shown its importance as an interspecific communication pathway. There is mounting evidence that QS molecules, commonly known as autoinducers also regulate phenotypes in members of different, unrelated species. As the human body is host to vast numbers of bacteria from a variety of different species, which can be synergistic or pathogenic in nature, of particular interest in this context is the QS mediated interaction between bacteria and eukaryotic cells. Along this line of research we have started to examine the yeast Saccharomyces cerevisiae (baker's yeast). When exposed to a variety of QS molecules (QSMs) from different bacteria and from Candida albicans we found that certain particular QSMs induced a specific stress response in S. cerevisiae. mRNA micro array experiments confirmed and strengthened these data, showing a unique and specific expression pattern that differed significantly from the response to previously described yeast stress factors.  We are currently aiming to identify and characterize the yeast receptor for this signaling molecule.