Special Seminar Dept. of Chemistry

Prof. Yftah Tal-Gan from the University of Nevada-Reno will give a seminar on 2.11.2026 at 14:00 
in the seminar room (shelter, ground floor) of building 208

Utilizing Chemical Biology Tools to Study Cell Signaling in Bacteria
Yftah Tal-Gan
Department of Chemistry, University of Nevada, Reno, 1664 N. Virginia Street, Reno, NV, 89557, USA

The Streptococcus genus includes commensal and pathogenic Gram-positive bacteria, many of which are 
frequently found co-colonizing the same natural niches, such as the oral cavity, nasopharynx, and the upper 
respiratory tract. Streptococci species utilize the competence regulon quorum sensing (QS) circuitry to 
govern competence, along with biofilm formation and virulence factor production, as well as in interspecies 
competition between streptococci through the production of bacteriocins and other toxic agents. We 
investigate the molecular mechanisms that drive signal peptide-receptor binding and lead to QS activation 
and interrogate the role of QS in the competition between streptococci species. To this end we develop 
peptide-based QS modulators with distinct activity profiles (selective vs. pan-species modulators; inhibitors 
vs. activators) and utilize them to determine the effects of QS modulation in single-species, mixed 
streptococci cultures, and in vivo.