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Interaction of small G proteins with photoexcited rhodopsin
Author(s) -
Wieland Thomas,
Ulibarri Isabel,
Aktories Klaus,
Gierschik Peter,
Jakobs Karl H.
Publication year - 1990
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(90)81372-u
Subject(s) - heterotrimeric g protein , transducin , g protein , rhodopsin , gtp binding protein regulators , adp ribosylation , gtp' , microbiology and biotechnology , biochemistry , gtpase activating protein , biology , chemistry , protein subunit , biophysics , signal transduction , retinal , enzyme , nad+ kinase , gene
Bovine rod outer segment (ROS) membranes contain in addition to the heterotrimeric G protein transducin, several small GTP‐binding proteins (23–27 kDa). Furthermore, these membranes contain two substrate proteins (about 22 and 24 kDa) for botulinum C3 ADP‐ribosyltransferase known to ADP‐ribosylate small G proteins in any mammalian cell type studied so far. Most interestingly, [ 32 P]ADP‐ribosylation of ROS membrane small G proteins by C3 is regulated by light and guanine nucleotides in a manner similar to pertussis toxin‐catalyzed [ 32 P]ADP‐ribosylation of the α‐subunit of transducin. These findings suggest that not only the heterotrimeric G protein transducin but also the C3 substrate small G proteins present in ROS membranes interact with photoexcited rhodopsin and thus contribute to its signalling action.