Activity profiling of plant serine hydrolases involved in defense

• Applicant: Professor Dr. Renier A.L. van der Hoorn
• Subject Area: Plant Biochemistry and Biophysics
• Term: from 2007 to 2010
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 46588632

Activities of proteomes can be displayed through ‘activity-based profiling’, which is based on the use of tagged, mechanism-based inhibitors (probes) that react with whole classes of enzymes in an activity-dependent manner. This technology has been successfully applied in medical research, revealing numerous novel aspects of human diseases. I have introduced activity profiling of papain-like cysteine proteases in plants and displayed intriguing dynamics of their activities during plant-pathogen interactions. Now I am requesting a grant for an experienced chemical biologist to establish activity-based profiling for plant serine proteases. With over 250 enzymes, this is the largest class of proteolytic enzymes in plants, but little is known about their activities and functions. The aim is to test five different classes of serine protease probes. Preliminary experiments demonstrate that these probes target multiple proteins in Arabidopsis leaf proteomes. Profiling will be optimized and characterized in vitro (on extracts) and in vivo (in living tissue). Targets of the probes will be identified by mass spectrometry and will be confirmed through overexpression, reverse genetics and/or use of antibodies.

• DFG Programme: Research Grants