Désensibilisation par les gonadotropines de leurs cellules-cibles

National audienc

Désensibilisation par les gonadotropines de leurs cellules-cibles

National audienc

Beta 2 adrenergic receptors mediate cAMP, tissue-type plasminogen activator and transferrin production in rat Sertoli cells

International audienc

Rat G Protein-Coupled Receptor Kinase GRK4: Identification, Functional Expression, and Differential Tissue Distribution of Two Splice Variants

International audienceG protein-coupled receptor kinases (GRKs) specifically phosphorylate the agonist-occupied form of G protein-coupled receptors, leading to the homologous mode of desensitization. We report here on the cloning of complementary DNAs that encode two rat GRK4 variants. Rat GRK4A (575 amino acids) displays 76% identity with the long human GRK4 splice variant. Rat GRK4B (545 amino acids) delineates a new variant that is identical to GRK4A except for a 31-amino acid deletion in the N-terminal domain, corresponding to exon VI in the human GRK4 gene. GRKs4A and B are likely produced by alternative splicing from a single gene, the partial characterization of which revealed a structural organization similar to that of the human GRK4 gene. GRK4A messenger RNA (mRNA) is abundant only in testis. A combination of in situ hybridization and quantitative RT-PCR studies demonstrated that GRK4A mRNA level increases during testicular development and predominates in leptotene to late pachytene primary spermatocytes and round spermatids. GRK4B mRNA is poorly expressed in testis and most rat tissues but is heterogeneously distributed in the kidney, with 20-fold enrichment in the outer medulla. GRKs4A and B are both functional protein kinases, as demonstrated in a rhodopsin phosphorylation assay. The differential tissue distribution of GRKA4 and GRK4B suggests that individual GRK4 variants may serve distinct physiological functions

G Protein-coupled receptor kinases and beta arrestins are relocalized and attenuate cyclic 3', 5' -adenosine monophosphate response to follicle-stimulating hormone in rat primary sertoli cells

International audienc

Expression of horse and donkey LH in COS-7 cells : evidence for low FSH activity in donkey LH compared with horse LH

International audienc

Kinase-inactive G-protein-coupled receptor kinases are able to attenuate follicle-stimulating hormone-induced signaling

International audienc

Expression of horse and donkey LH in COS-7 cells : evidence for low FSH activity in donkey LH compared with horse LH

International audienc

Involvement of G protein-coupled receptor kinases and arrestins in desensitization to follicle-stimulating hormone action

International audienc