Photosensitivity of 8BrcGMP‐induced conductance in ROS‐excised patches

FEBS Letters

Khalifa-Zade, M.Ch.¹  Kolesnikov, S.S.¹  Kosolapov, A.V.¹ 

[1] Institute of Cell Biophysics, Russian Academy of Sciences, Pushchino, Moscow Region, 142292, Russia

关键词: Retinal rod;    Phototransduction;    cGMP-gated channel;    IBMX;    3-isobutyl-1-methylxanthine;    PDE;    phosphodiesterase;    ROS;    rod outer segment;   

DOI  :  10.1016/0014-5793(92)80660-9

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Inside-out patches from ROS plasma membranes contain the basic enzymes of the phototransduction cascade. Similar to a native photoreceptor cell, such patches are capable of responding to light, the effect of which suppresses the cGMP-activated current. Photoresponses are observed only in the presence of GTP, whereas ATP essentially accelerates the current recovery to a dark level. Photoresponses are also observed in the presence of 8BrcGMP. Phosphodiesterase (PDE) hydrolyzes 8BrcGMP two orders of magnitude slower than cGMP, so the light inhibition of the 8BrcGMP-induced current cannot be accounted for by PDE activation. It seems that activity of cGMP-gated channels depends not only on cGMP concentration, but is additionally controlled by some other regulatory mechanisms.

【 授权许可】

Unknown