The function of the C-terminal half of Channelrhodopsins and of predicted novel rhodopsins from the green alga Chlamydomonas reinhardtii

• Applicant: Professor Dr. Georg Nagel
• Subject Area: Plant Physiology
• Term: from 2009 to 2013
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 112805507

Channelrhodopsins (ChR1 and ChR2) from the green alga Chlamydomonas reinhardtü were functionally characterized in-vivo and after expression In animal cells. Their N-terminal half constitutes a directly light-gated cation channel which finds increasing use as a tool to light-manipulate neuronal activity. [This part of the project was not recommended for funding: The function of the C-terminal half is completely unknown for both channelrhodopsins. We plan to investigate the role of the recently identified phosphorylation sites on the C-terminus of ChR by analyzing functional consequences of co-expressing suitable kinases or by expressing phosphorylation site mutants.] New rhodopslns with predicted cyclase domains were identified in the genome of Chlamydomonas reinhardtü. We plan to express the predicted proteins or domains derived from these sequences. If functional expression of the whole protein fails we plan to swap domains with predicted cyclase activity into the corresponding domains of well studied cyclases to characterize the function of the predicted domain. Alternatively, established cyclase domains will be swapped against the predicted cyclase domain of the rhodopsin to test for light-modulation of cyclase activity.

• DFG Programme: Research Units
• Subproject of: FOR 1261: Specific Light Driven Reactions in Unicellular Model Algae