The biological function of ovothiol A in Chlamydomonas reinhardtii

• Applicant: Professor Dr. Severin Sasso
• Subject Area: Plant Biochemistry and Biophysics
• Term: from 2015 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 290461445

Ovothiols are sulphur-containing compounds derived from histidine that are produced by marine invertebrates, trypanosomatids and certain bacteria, fungi and algae. Until recently, investigations of ovothiol function have been hampered by the lack of knowledge about genes responsible for ovothiol biosynthesis. In marine invertebrates, ovothiols may protect the egg from reactive oxygen species (ROS) that are formed during fertilisation. In unicellular algae, the function of ovothiol is less clear. The recent discovery of the first enzyme of ovothiol biosynthesis (Braunshausen und Seebeck, J. Am. Chem. Soc. 133, 1757-1759 (2011)) has allowed us to construct a mutant of the unicellular model alga Chlamydomonas reinhardtii that has lost the ability to make ovothiol. In a first phenotypic test, the growth of this ovothiol mutant was impaired under high light. This result suggests a role of ovothiol in ROS detoxification or redox signalling in C. reinhardtii. In a series of experiments, this project will characterise the C. reinhardtii knock-out mutant in detail. In addition, ovothiol biosynthesis and possible interactions between ovothiol and proteins will be investigated. Together, the results of this project will contribute to a better understanding of molecular and cellular processes in which ovothiol plays an important role.

• DFG Programme: Research Grants