The latency of the light response is modulated by the phosphorylation state of Drosophila TRP at a specific site

Publication Type

Journal contribution

Authors

Katz, B., Voolstra, O., Tzadok, H., Yasin, B., Rhodes-Modrov, E., Bartels, J.-P., Strauch, L., Huber,A., and Minke, B.

Year of publication

2017

Published in

Channels

Pubisher

Taylor & Francis Group , UK

Band/Volume

11/6

DOI

10.1080/19336950.2017.1361073

Page (from - to)

678-685

Drosophila photoreceptors respond to oscillating light of high frequency (∼100 Hz), while increasing the oscillating light intensity raises the maximally detected frequency. Recently, we reported that dephosphorylation of the light-activated TRP ion channel at S936 is a fast, graded, light-, and Ca²⁺-dependent process. We further found that this process affects the detection limit of high frequency oscillating light. Accordingly, transgenic Drosophila, which do not undergo phosphorylation at the S936-TRP site (trp^S936A), revealed a short time-interval before following the high stimulus frequency (oscillation-lock response) in both dark- and light-adapted flies. In contrast, the trp^S936D transgenic flies, which mimic constant phosphorylation, showed a long-time interval to oscillation-lock response in both dark- and light-adapted flies. Here we extend these findings by showing that dark-adapted trp^S936A flies reveal light-induced current (LIC) with short latency relative to trp^WT or trp^S936D flies, indicating that the channels are a limiting factor of response kinetics. The results indicate that properties of the light-activated channels together with the dynamic light-dependent process of TRP phosphorylation at the S936 site determine response kinetics.