Counterregulation of cAMP-directed kinase activities controls ciliogenesis

Margherita Santoriello,Herbert H Lindner,Monia Porpora,Ivan Conte,Antonio Feliciello,Matthis Synofzik,Rossella Delle Donne,Daniela Intartaglia,Simona Sauchella,Eduard Stefan,Omar Torres-Quesada,Verena A Bachmann,Laura Rinaldi,Maria Sepe,Luigi Insabato,Corrado Garbi

doi:10.1038/s41467-018-03643-9

Abstract

The primary cilium emanates from the cell surface of growth-arrested cells and plays a central role in vertebrate development and tissue homeostasis. The mechanisms that control ciliogenesis have been extensively explored. However, the intersection between GPCR signaling and the ubiquitin pathway in the control of cilium stability are unknown. Here we observe that cAMP elevation promotes cilia resorption. At centriolar satellites, we identify a multimeric complex nucleated by PCM1 that includes two kinases, NEK10 and PKA, and the E3 ubiquitin ligase CHIP. We show that NEK10 is essential for ciliogenesis in mammals and for the development of medaka fish. PKA phosphorylation primes NEK10 for CHIP-mediated ubiquitination and proteolysis resulting in cilia resorption. Disarrangement of this control mechanism occurs in proliferative and genetic disorders. These findings unveil a pericentriolar kinase signalosome that efficiently links the cAMP cascade with the ubiquitin-proteasome system, thereby controlling essential aspects of ciliogenesis.

Highlights

The primary cilium emanates from the cell surface of growth-arrested cells and plays a central role in vertebrate development and tissue homeostasis
Here we report the identification of a pericentriolar scaffold complex functionally nucleated by PCM1 that controls cAMP signaling events at the primary cilium
GPCR-mediated activation of PKA induces ubiquitination and proteolysis of Nima-related Kinase 10 (NEK10), which culminates in cilia resorption

Summary

Introduction

The primary cilium emanates from the cell surface of growth-arrested cells and plays a central role in vertebrate development and tissue homeostasis. We identify a multimeric complex nucleated by PCM1 that includes two kinases, NEK10 and PKA, and the E3 ubiquitin ligase CHIP. PKA phosphorylation primes NEK10 for CHIP-mediated ubiquitination and proteolysis resulting in cilia resorption Disarrangement of this control mechanism occurs in proliferative and genetic disorders. These findings unveil a pericentriolar kinase signalosome that efficiently links the cAMP cascade with the ubiquitinproteasome system, thereby controlling essential aspects of ciliogenesis. Components of the cAMP cascade, such as G-protein coupled receptors (GPCRs), adenylate cyclases (ACs), and phosphodiesterases (PDEs) are central signaling units that act on the primary cilium and are functionally implicated in critical aspects of cilium formation and signaling[12,13,14]. The orphan GPCR Gpr[161], known to be involved in cAMP and hedgehog signaling has been identified as a scaffolding protein

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