[Lack of negative regulation of beta-adrenoreceptor affinity by guanine nucleotides in embryonic membranes and its induction by the GTP-binding protein from mature protein].
The negative regulation of the beta-adrenoreceptor affinity by guanine nucleotides in the sarcolemmal fraction of chicken skeletal muscle at different stages of ontogenesis was studied. It was found that the negative regulation is absent in the embryonic period; the effect of GTP is manifested only before hatching, whereas that of Gpp(NH)p--at later periods, i.e., in 1-month-old chickens. Similar age-dependent dynamics was revealed with respect to the GTP effect on the dissociation rate of the [3H]DHA-beta-adrenoreceptor complex. An addition to the system containing embryonic muscle membranes of the GTP-binding protein isolated from skeletal muscle and liver of chickens whose age exceeds 20 days led to earlier manifestations of the above effects (on the 13th-15th embryonic days). The data obtained testify to the limiting role of GTP-binding proteins in the negative control of the hormone-receptor interaction and support the authors' hypothesis on the absence in the embryonic muscle of the 42 kD GTP-binding protein responsible for the functional coupling of the hormone-sensitive adenylate cyclase components.
Kuznetsova
L A
LA
Pertseva
M N
MN
Plesneva
S A
SA
D000375:Aging / Q000502:physiology*; D000818:Animals; D002642:Chick Embryo; D002645:Chickens; D019204:GTP-Binding Proteins / Q000502:physiology*; D006150:Guanine Nucleotides / Q000502:physiology*; D007425:Intracellular Membranes / Q000502:physiology; D007545:Isoproterenol / Q000378:metabolism; D011943:Receptors, Adrenergic, beta / Q000502:physiology*; D012508:Sarcolemma / Q000502:physiology*
D006150:Guanine Nucleotides; D011943:Receptors, Adrenergic, beta; D019204:GTP-Binding Proteins; D007545:Isoproterenol
Otsytstvie negativnoĭ reguliatsii srodstva beta-adrenoretseptorov guaninovymi nukleotidami v émbrional'noĭ membrane i induktsiia ee GTP-sviazyvaniushchim belkom zreloĭ tkani.