Sensory primary cilium is a responsive cAMP microdomain in renal epithelia

Abstract

Primary cilia are hair-like cellular extensions that sense microenvironmental signals surrounding cells. The role of adenylyl cyclases in ciliary function has been of interest because the product of adenylyl cyclase activity, cAMP, is relevant to cilia-related diseases. In the present study, we show that vasopressin receptor type-2 (V2R) is localized to cilia in kidney epithelial cells. Pharmacologic inhibition of V2R with tolvaptan increases ciliary length and mechanosensory function. Genetic knockdown of V2R, however, does not have any effect on ciliary length, although the effect of tolvaptan on ciliary length is dampened. Our study reveals that tolvaptan may have a cilia-specific effect independent of V2R or verapamil-sensitive calcium channels. Live-imaging of single cilia shows that V2R activation increases cilioplasmic and cytoplasmic cAMP levels, whereas tolvaptan mediates cAMP changes only in a cilia-specific manner. Furthermore, fluid-shear stress decreases cilioplasmic, but not cytoplasmic cAMP levels. Our data indicate that cilioplasmic and cytoplasmic cAMP levels are differentially modulated. We propose that the cilium is a critical sensor acting as a responsive cAMP microcompartment during physiologically relevant stimuli.

Primary cilium-dependent cAMP/PKA signaling at the centrosome regulates neuronal migration

“…S1), similar to what was described recently (5). The PC is a cAMP-rich region (10)(11)(12)(13), raising the possibility that the cAMP hotspot at the centrosome could be PC-dependent. To test this hypothesis, we used two mouse lines in which ablation of the PC can be genetically-induced by Cre recombination (Kif3a lox/lox and Rpgrip1l lox/lox mice).…”

“…As the PC is a cAMP-rich source (10)(11)(12)(13), we asked whether it could regulate neuronal migration through cAMP dynamics, in the context of migration along the postnatal Rostral Migratory Stream (RMS) from the ventricular/subventricular zone to olfactory bulb (OB) ( Fig. 1A).…”

Nanobody-directed targeting of optogenetic tools to study signaling in the primary cilium

“…Furthermore, GPCR signaling pathways use cAMP as a second messenger for signal transduction. Primary cilia are enriched in specific GPCRs, for example 5-HT 6 , V2R, EP4, SSTR3, or GPR120 ( Jin et al, 2014 ; Berbari et al, 2008 ; Nachury and Mick, 2019 ; Sherpa et al, 2019 ; Hilgendorf et al, 2019 ; Hilgendorf et al, 2016 ). Thus, the function of these GPCR-dependent signaling pathways could be analyzed with spatial and temporal resolution using our approach.…”

Primary cilium-dependent cAMP/PKA signaling at the centrosome regulates neuronal migration

“…1A). Centrosome dynamics is thus pivotal in the regulation of migration, through microtubular centrosome to nucleus coupling allowing NK (8)(9)(10)(11)(12).…”