Mono ADP‐ribosylation of transducin catalyzed by rod outer segment extract

FEBS Letters

Virmaux, Noélle¹  Nullans, Gërard¹  Ehret-Hilberer, Sylviane¹  Aunis, Dominique¹ 

[1] INSERM Unité 338. 5 rue Blaise Pascal, 67084 Strasbourg Cedex, France

关键词: Transducin;    ADP-ribosylation;    Rod outer segment;    G protein;    Rhodopsin;    Retina;    DTT;    dithiothreitol;    cGMP-PDE;    cyclic guanosine monophosphate-phosphodiesterase;    GTPγS;    guanosine-5′-O(3-thiotriphosphate);    NAD*;    nicotinamide adenine dinucleotide;    NEM;    N-ethylmaleimide;    PDE 1;    snake venom phosphodiesterase 1;    ROS;    rod outer seaments;    Tα;    Tβ and Tγ;    Tα;    Tβ and Tγ;    TLC;    thin layer chromatography;   

DOI  :  10.1016/0014-5793(92)80814-W

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Transducin is the retinal rod outer segment (ROS)-specific G protein coupling the photoexcited rhodopsin to cyclic GMP-phosphodiesterase. The α subunit of transducin is known to be ADP-ribosylated by bacterial toxins. We investigated the possibility that transducin is modified in vitro by an endogenous ADP-ribosyltransferase activity. By using either ROS, cytosolic extract of ROS or purified transducin in the presence of [α??P]nicotinamide adenine dinucleotide (NAD*), the α and β subunits of transducin were found to be radiolabeled, The labeling was decreased by snake venom phosphodiesterase I (PDE 1). The modification was shown to be mono ADP-ribosylation by analyses on thin layer chromatography of the PDE 1-hydrolyzed products which revealed only 5′AMP residues. In addition we report that sodium nitroprusside activates the ADP-ribosylation of transducin.

【 授权许可】

Unknown