Endocrine Abstracts

The physiological effects of the pituitary hormone, adrenocorticotropic hormone (ACTH) on the adrenal are mediated by the melanocortin 2 receptor (MC2R), a G protein coupled receptor (GPCR) that signals via adenylate cyclase to elevate intracellular cyclic AMP (cAMP) levels. Therefore the expression and function of the receptor are likely to be the major determinants of the response to ACTH. Following repeated stimulation, the cAMP signal is diminished or desensitised. Desensi...

Introduction: G protein coupled receptor dimerization is proposed to have great impact on receptor signaling. Allosteric communication between the protomers of a dimer can alter ligand binding, receptor conformation and the interactions with different effector proteins. Although the concept of intradimeric interactions is widely accepted, the molecular mechanism behind them is not clearly understood. In this study we investigated the allosteric interactions within the type I a...

Background: Loss of function mutations of the type-2 vasopressin receptor (V2R) in kidney lead to nephrogenic diabetes insipidus (NDI). The function of mutant receptors can be rescued using ligands resulting sufficient amount of plasma membrane localized V2Rs in a conformation which are able to generate cAMP signal. We examined a previously described, not characterized mutation. In order to determine personalized therapy for the individual the properties of the mutant receptor...

Introduction: β-Arrestins are cytosolic proteins, which play key roles in the desensitization, internalization and signaling of G protein-coupled receptors. Currently, little is known about the role of β-arrestins in the internalization of the CB1 cannabinoid receptor (CB1R). Therefore, the interaction between β-arrestins and CB1R, and its role in receptor internalization were studied.Materials and methods: The β-arrestin binding of C...

The octapeptide hormone angiotensin II (Ang II) exerts its major biological effects via angiotensin AT1 receptors (AT1Rs). Signaling of AT1Rs is regulated by ß-arrestins, which bind to activated AT1Rs, uncouple them form G proteins, and initiate their internalization via clathrin-coated pits and cause G protein independent MAP kinase activation. It has been shown previously that AT1Rs internalize via ß-arrestin-d...

The angiotensin II (AngII) hormone exerts a number of biological effects through the type 1 angiotensin II receptor (AT1R). One of the main targets of AngII are vascular smooth muscle cells, their stimulation activates many signaling pathways and results in gene expression changes.Affymetrix Gene Chip experiments were performed to analyze the effects of AngII stimulation on gene expression. For the determinations, aortic thoracic aorta from young male Wi...

Introduction: Multiple endocrine neoplasia type 1 (MEN 1) may present as a familial or a sporadic disorder with multiple endocrine tumours including parathyroid adenomas or hyperplasias, tumours of endocrine pancreatic and pituitary gland. Familial and sporadic MEN 1-related states which do not fulfill current diagnostic criteria but may be related to MEN 1 syndrome have been also described.Aims: The aim of this study was to examine the prevalence and sp...