Overlapping genes inNalp6/PYPAF5locus encode two V2-type vasopressin isoreceptors: angiotensin-vasopressin receptor (AVR) and non-AVR

Abstract

The angiotensin-vasopressin receptor (AVR) responds with equivalent affinities to angiotensin II (ANG II) and vasopressin and is coupled to adenylate cyclase and hence a V2-type vasopressin receptor. AVR maps to the Nalp6 locus and overlaps with the larger Nalp6/PYPAF5 reported to be a T cell/granulocyte-specific, cytoplasmic-specific proapoptotic protein, thus questioning the existence of AVR. Here we confirm, through different experimental modalities, that AVR is distinct from Nalp6/PYPAF5 based on different mRNA and protein sizes, subcellular localization, and tissue-specific expression patterns. Binding studies of PYPAF5-specific Cos1 transfectants detect high-affinity binding to vasopressin but not ANG II, thus assigning PYPAF5 as a non-AVR (NAVR). Signaling array analysis reveals that AVP stimulation of AVR- and NAVR-specific Cos1 transfectants results in diametrical activation as well as coactivation of signaling pathways known to mediate renal sodium and water balance. Likewise, ANG II stimulation of Cos1-AVR transfectants reveals a signaling profile distinct from that of AVP-stimulated Cos1-AVR transfectants. Analysis of genomic organization of the AVR/NAVR locus shows an overlapping gene arrangement with alternative promoter usage resulting in different NH(2) termini for NAVR and AVR. In addition to core promoter elements, androgen and estrogen response elements are detected. Promoter analysis of NAVR/AVR 5'-regulatory region detects transcriptional upregulation by testosterone and synergistic upregulation by testosterone and estrogen, thus suggesting that AVR and/or NAVR contribute to sex-specific V2-type vasopressin-mediated effects. Altogether, confirmation of AVR and identification of NAVR as vasopressin receptors are concordant with emerging vasopressin functions not attributable to V1a, V1b, or V2 receptors and add molecular bases for the multifunctional complexity of vasopressin-mediated functions and regulation.

Nod-like receptor pyrin domain-containing protein 6 (NLRP6) controls epithelial self-renewal and colorectal carcinogenesis upon injury

“…We provided compelling evidence for an important role of NLRP6 in selfrenewal of the intestinal epithelium. Importantly, absence of NLRP6 resulted in defective wound healing in response to trauma that were triggered either by biopsy or by exposure to DSS, perhaps through a failure of enterocytes to activate STAT3 (26). The discovery of a NLR controlling colonic myofibroblast function and interaction with adjacent epithelial progenitors at the bottom of the crypts was unexpected.…”

AVR/NAVR deficiency lowers blood pressure and differentially affects urinary concentrating ability, cognition, and anxiety-like behavior in male and female mice

“…We have elucidated a noncanonical AVP receptor system contained in two overlapping AVP receptors, AVR (a dual angiotensin-vasopressin receptor) and NAVR (a nonangiotensin, vasopressin receptor) both expressed from a single gene by alternative promoter usage and upregulated synergistically by testosterone and estrogen (17) The mouse AVR sequence is contained within NAVR's amino acid residues 424 -878. NAVR binds AVP exclusively, while AVR portrays highaffinity binding sites for both ANG II and AVP (17).…”

“…NAVR binds AVP exclusively, while AVR portrays highaffinity binding sites for both ANG II and AVP (17). AVR and NAVR are abundantly expressed in kidney and to a lesser extent in brain, liver, lung, adrenal gland, heart, and aorta (17,47).…”

DEspR T/CATAAAA-box promoter variant decreases DEspR transcription and is associated with increased BP in Sardinian males

“…We measured transcriptional activity in three cell lines, two of renal origin (HEK293, human embryonic kidney cell line; Cos1, monkey kidney cell line) and one human mammary tumor cell line (MDA-MB-468, ATCC) since DEspR is detected prominently in kidney (6) and mammary tumor cells (V. L. M. Herrera, N. Ruiz-Opazo, unpublished results). Transfections were performed essentially as described (11). Cells were maintained in appropriate growth media.…”