Normal Phototransduction in Drosophila Photoreceptors Lacking an InsP3 Receptor Gene

@article{Raghu2000NormalPI,
  title={Normal Phototransduction in Drosophila Photoreceptors Lacking an InsP3 Receptor Gene},
  author={Padinjat Raghu and Nansi Jo Colley and Rebecca Webel and Tracy James and Gaiti Hasan and Michal Danin and Zvi Selinger and Roger C. Hardie},
  journal={Molecular and Cellular Neuroscience},
  year={2000},
  volume={15},
  pages={429-445}
}
The Drosophila light-sensitive channels TRP and TRPL are prototypical members of an ion channel family responsible for a variety of receptor-mediated Ca(2+) influx phenomena, including store-operated calcium influx. While phospholipase Cbeta is essential, downstream events leading to TRP and TRPL activation remain unclear. We investigated the role of the InsP(3) receptor (InsP(3)R) by generating mosaic eyes homozygous for a deficiency of the only known InsP(3)R gene in Drosophila. Absence of… Expand
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Phototransduction in Drosophila Is Compromised by Gal4 Expression but not by InsP3 Receptor Knockdown or Mutation
TLDR
Several GMRGal4 phenotypes suggestive of compromised development are described, including reductions in sensitivity, dark noise, potassium currents, and cell size and capacitance, as well as extreme variations in sensitivity between cells. Expand
Phototransduction mechanisms in Drosophila microvillar photoreceptors
TLDR
Ca2+ influx via TRP channels is essential for rapid kinetics, amplification, and light adaptation and mediates both positive and negative feedback via multiple downstream targets, including the channels, rhodopsin, and PLC. Expand
Mechanisms of Light Adaptation in Drosophila Photoreceptors
TLDR
The results indicate that light adaptation is primarily mediated downstream of PLC and independently of PKC by Ca(2+)-dependent inhibition of TRP channels, which is interpreted as a strategy to prevent inhibition of PL by global steady-state light-adapted Ca( 2+) levels, whereas rapid inhibition ofPLC by localCa(2+) transients is required to terminate the response and ensures that PIP(2) reserves are not depleted during stimulation. Expand
Functional INAD complexes are required to mediate degeneration in photoreceptors of the Drosophila rdgA mutant
TLDR
The results demonstrate a previously unknown requirement for a balance of PLCβ and DGK activity for retinal degeneration in rdgA and suggest a key role for the lipid products of phosphoinositide hydrolysis in the activation of TRP channels in vivo. Expand
Calcium Influx via TRP Channels Is Required to Maintain PIP2 Levels in Drosophila Photoreceptors
TLDR
The results suggest that Ca2+ influx prevents PIP2 depletion by inhibiting PLC activity and facilitating PIP1 recycling and preventing inactivation in trp. Expand
Activation of TRP Channels by Protons and Phosphoinositide Depletion in Drosophila Photoreceptors
TLDR
It is shown that light induces a rapid (<10 ms) acidification originating in the microvilli, which is eliminated in mutants of PLC, and that heterologously expressed TRPL channels are activated by acidification of the cytosolic surface of inside-out patches. Expand
1.05 – Phototransduction in Microvillar Photoreceptors of Drosophila and Other Invertebrates
TLDR
Invertebrate microvillar photoreceptors depolarize in response to light by opening nonselective cation channels, and several components of the cascade, including TRP, PLC, and protein kinase C (PKC) are assembled into a multimolecular signaling complex by the scaffolding protein INAD. Expand
Phototransduction and retinal degeneration in Drosophila
  • T. Wang, C. Montell
  • Biology, Medicine
  • Pflügers Archiv - European Journal of Physiology
  • 2007
TLDR
Drosophila visual transduction appears to have particular relevance to the cascade in the intrinsically photosensitive retinal ganglion cells in mammals, as the photoresponse in these latter cells appears to operate through a remarkably similar mechanism. Expand
A Common Mechanism Underlies Vertebrate Calcium Signaling andDrosophila Phototransduction
TLDR
The results indicate an important link in the coupling mechanism of vertebrate store-operated channels and Drosophila TRP channels, which involves the InsP3 branch of the inositol lipid-signaling pathway. Expand
TRP, TRPL and Cacophony Channels Mediate Ca2+ Influx and Exocytosis in Photoreceptors Axons in Drosophila
TLDR
New light is shed on the mechanism of neurotransmitter release in tonic synapses of non-spiking neurons in Drosophila by studying the distribution and physiological properties of TRP and TRPL in the lamina of the visual system. Expand
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