Interaction of recombinant rho A GTP-binding proteins with photoexcited rhodopsin.
The small molecular mass GTP-binding proteins rho A, B and C are targets for ADP-ribosyltransferase activity of the botulinum exoenzyme C3. The possible interaction of recombinant rho A proteins expressed in E. coli with photoexcited rhodopsin was studied by reconstitution with bovine rod outer segment (ROS) membranes depleted of endogenous GTP-binding proteins by treatment with urea. As reported for C3 substrates present in untreated ROS membranes, ADP-ribosylation of recombinant rho A proteins, both normal and Val-14 mutant, by C3 was inhibited when reconstituted with illuminated compared to dark-adapted ROS membranes pretreated with urea. GDP reduced the light-induced inhibition, while GTP[S] and light inhibited ADP-ribosylation of rho A proteins in a synergistic manner.
Wieland
T
T
Pharmakologisches Institut, Universität Heidelberg, FRG.
Ulibarri
I
I
Gierschik
P
P
Hall
A
A
Aktories
K
K
Jakobs
K H
KH
D000246:Adenosine Diphosphate Ribose / Q000378:metabolism; D000818:Animals; D002417:Cattle; D019204:GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D006153:Guanosine Diphosphate / Q000378:metabolism; D006801:Humans; D008027:Light; D011485:Protein Binding; D011994:Recombinant Proteins / Q000378:metabolism; D012243:Rhodopsin / Q000378:metabolism*; D012374:Rod Cell Outer Segment / Q000378:metabolism; D015293:Transducin / Q000378:metabolism; D020742:rhoA GTP-Binding Protein
D011994:Recombinant Proteins; D006153:Guanosine Diphosphate; D000246:Adenosine Diphosphate Ribose; D012243:Rhodopsin; D019204:GTP-Binding Proteins; D015293:Transducin; D020742:rhoA GTP-Binding Protein