Invertebrate Phototransduction

Question 1

TRP activation by PLC

Answer 1

Hardie, 2011

Question 2

Challenge to TRP activation by PLC

Answer 2

Montell, 2012

Question 3

Protonophore (DNP) → ATP depletion opens channels

Answer 3

Montell, 2012

Question 4

Activation equally effective with/without ATP in patch clamp; unaffected by oligomycin

Answer 4

Agam et al, 2004

Question 5

PUFA-induced channel activity suppressed by mechanosensitive-channel inhibitor

Answer 5

Parnas et al

Question 6

Ca2+ influx mediates 30% light-dependent current

Answer 6

Chu et al

Question 7

Negative feedback on TRP/TRPL terminates quantum bumps and accounts for major features of light adaptation

Answer 7

Gu et al

Question 8

Phototransduction in Drosophila depends on Ca2+-release mediated signalling; TRP is essential for the normal function of this process

Answer 8

Cook and Mink (1999)

Question 9

Constitutive activity of TRP/TRPL in rdgA DAG kinase mutant; uncontrolled calcium influx leads to cytotoxicity

Answer 9

Raghu et al, 2000

Question 10

Ca2+-dependent metarhodopsin inactivation mediated by calmodulin and NINAC myosin II

Answer 10

Liu et al, 2008

Question 11

Ca2+ influx at rhabdomeres generates large-amplitude transient; dispersion of intracellular Ca2+ stores does not mimic/interfere with photoexcitation

Answer 11

Ranganathan et al, 1994

Question 12

Functional cooperation between IP3 receptor and phospholipase C secures high sensitivity to light of Drosophila photoreceptors in vivo

Answer 12

Kohn et al, 2016

Question 13

Phototransduction in Drosophila is compromised by Gal4 expression but not by IP3R knockdown or mutation

Answer 13

Bollepalli et al, 2017

Question 14

 PLCβ activated by Gqα; Gqα essential for activation of phototransduction cascade; manipulation of sensitivity by expression

Answer 14

Scott et al (1995)

Question 15

Trp gene is essential for a light-activated Ca2+ channel in drosophila photoreceptors

Answer 15

Hardie and Minke (1992)

Question 16

Activation of TRP channels by protons and phosphoinositide depletion in Drosophila photoreceptors

Answer 16

Huang et al, 2010

Question 17

Regulation of Drosophila TRPL channels by PLC-dependent mechanisms

Answer 17

Estacion et al, 2004

Question 18

inaD serves as scaffold to assemble components of phototransduction cascade

Answer 18

Tsunoda et al, 1997

Question 19

Amplification requires activation of multiple G protein and PLC molecules; DGK = key enzyme regulating amplification; DAG implicated as messenger of excitation in Drosophila phototransduction

Answer 19

Hardie et al, 2002

Question 20

Photolysis of caged Ca2+ facilitates and inactivates but does not directly excite light-sensitive channels in Drosophila photoreceptors

Answer 20

Hardie et al, 1995

Question 21

Ectopic expression of mouse melanopsin in Drosophila photoreceptors

Answer 21

Yasin et al, 2017

Question 22

Support for DAG as membrane-soluble messenger; PIP-depletion model cannot account for all results

Answer 22

Delgado et al, 2019