Showing papers by "Michel Bouvier published in 1999"
TL;DR: Evidence is provided that, contrary to what is currently postulated, receptor endocytosis is not a necessary prerequisite for beta(2)AR down-regulation and that the inactivation of beta( 2)ARs, leading to a reduction in binding sites, may occur at the plasma membrane.
104 citations
TL;DR: Given that, upon activation, the fusion protein mimics the activated receptor-G protein complex but cannot undergo desensitization, the data demonstrate that early steps in the activation process lead to the depalmitoylation of both receptor and G protein and that repalMIToylation requires later events that cannot be accommodated by the activated fusion protein.
58 citations
TL;DR: It appears that NPR-A alone can account for the two binding components found in the rat papillae and that a single molecular form of the protein is implicated.
Abstract: The natriuretic peptide receptor-A (NPR-A) is involved in blood pressure and body fluid regulation in order to help maintain cardiovascular homeostasis. It has been shown that these biological effects are mediated through the natriuretic peptide family of hormones, which bind NPR-A according to the rank order ANP>BNP>>CNP. Previous studies performed with rat kidney papillary tissue suggested the existence of an heterologous NPR-A population since two binding components were obtained for pBNP32, one of high affinity (pK 9.4 ± 0.1) and the other of lower affinity (pK 7.5 ± 0.1), while in the same preparation rANP28M binding displayed the expected affinity (pK 10.22 ± 0.01) and was best fitted with a model involving a single class of binding sites. This apparent heterogeneity of NPR-A in rat kidney papillae could be explained by the presence of two receptor isoforms or of monomeric and oligomeric forms of the same receptor. To investigate the NPR-A binding heterogeneity, we have cloned the rat NPR-A from PC12 cells and compared its pharmacological profile with that of the papillae. Our results with rat NPR-A transfected Cos-P cells show an equivalent pharmacological profile as with the rat tissue, i.e. a high affinity for rANP28 (pK 10.4 ± 0.1) and two distinctive affinities for pBNP32 (pK 9.74 ± 0.05 and 7.8 ± 0.1). Although multiple receptor glycoforms were sometimes detectable by western blotting, only one molecular form was obtained by cross-linking with 125I- rANP28. It thus appears that NPR-A alone can account for the two binding components found in the rat papillae and that a single molecular form of the protein is implicated. We therefore propose that the oligomerization state of the receptors could be responsible for the apparent binding heterogeneity of rat NPR-A.
8 citations
1 citations