ELSC News

Article of the Month, 06/2017 - Minke's lab

June 5, 2017

Authors: Voolstra et al. (Baruch Minke's Lab)

Drosophila photoreceptors exhibit high temporal resolution as manifested in membrane voltage response to oscillating light of high frequency (up to ~100 Hz). The detected maximal frequency is modulated by the light rearing conditions, thus maintaining both high sensitivity to light and temporal resolution via unclear mechanisms. Here, we show by combination of biochemistry and in vivo electrophysiology that TRP channel dephosphorylation at a specific site (S936) is a fast, light-activated, and Ca2+-dependent regulatory process. Strikingly, preventing phosphorylation of the S936-TRP site in transgenic Drosophila (trpS936A), abolished the difference in frequency response between dark- and light-adapted flies and fixed the maximal frequency response of both at high frequency. In contrast, inserting a phosphomimetic mutation (trpS936D) set the maximal frequency response of both dark-and light-adapted flies to low frequency. Thus, light dependent TRP dephosphorylation affects the detection limit of oscillating light according to the adaptation state of the photoreceptor cells by shifting the detection limit to higher frequencies upon light adaptation. This novel mechanism thus adjusts dynamic processing of visual information under varying light conditions.

nom 062017 - figure

Full article at:

The Phosphorylation State of the Drosophila TRP Channel Modulates the Frequency Response to Oscillating Light In Vivo