betagamma-Transducin stimulates hydrolysis and synthesis of phosphatidylinositol 4,5-bisphosphate in bovine rod outer segment membranes.
T betagamma was shown to stimulate the hydrolysis and synthesis of PtdInsP2 in dark-adapted bovine retinal rod outer segments. In contrast, T alphaGDP blocked the effect of betagamma-transducin. It was also demonstrated that T betagamma was a stimulator of 32P incorporation into PtdInsP2 in ROS. These findings explain the modulating actions of GTP and light on PtdInsP2 hydrolysis and synthesis in ROS. The possible existence of cross-talk between the cGMP and phosphoinositide cascades in retinal rods was discussed.
Grigorjev
I V
IV
Institute of Photobiology, Academy of Sciences of Belarus, Minsk.
Grits
A I
AI
Artamonov
I D
ID
Baranova
L A
LA
Volotovski
I D
ID
D000222:Adaptation, Physiological; D000818:Animals; D002417:Cattle; D002462:Cell Membrane / Q000187:drug effects; D006160:Guanosine Triphosphate / Q000494:pharmacology; D006868:Hydrolysis; D008027:Light; D019269:Phosphatidylinositol 4,5-Diphosphate / Q000096:biosynthesis*; D012374:Rod Cell Outer Segment / Q000187:drug effects* / Q000378:metabolism; D015293:Transducin / Q000037:antagonists & inhibitors / Q000494:pharmacology*
D019269:Phosphatidylinositol 4,5-Diphosphate; D006160:Guanosine Triphosphate; D015293:Transducin