PI3K class II α controls spatially restricted endosomal PtdIns3P and Rab11 activation to promote primary cilium function.
Multiple phosphatidylinositol (PtdIns) 3-kinases (PI3Ks) can produce PtdIns3P to control endocytic trafficking, but whether enzyme specialization occurs in defined subcellular locations is unclear. Here, we report that PI3K-C2α is enriched in the pericentriolar recycling endocytic compartment (PRE) at the base of the primary cilium, where it regulates production of a specific pool of PtdIns3P. Loss of PI3K-C2α-derived PtdIns3P leads to mislocalization of PRE markers such as TfR and Rab11, reduces Rab11 activation, and blocks accumulation of Rab8 at the primary cilium. These changes in turn cause defects in primary cilium elongation, Smo ciliary translocation, and Sonic Hedgehog (Shh) signaling and ultimately impair embryonic development. Selective reconstitution of PtdIns3P levels in cells lacking PI3K-C2α rescues Rab11 activation, primary cilium length, and Shh pathway induction. Thus, PI3K-C2α regulates the formation of a PtdIns3P pool at the PRE required for Rab11 and Shh pathway activation.
Molecular Biotechnology Center, Department of Molecular Biotechnology and Health Sciences, University of Torino, 10126 Torino, Italy.
Irene
I
Franco
Molecular Biotechnology Center, Department of Molecular Biotechnology and Health Sciences, University of Torino, 10126 Torino, Italy.
Federico
F
Gulluni
Molecular Biotechnology Center, Department of Molecular Biotechnology and Health Sciences, University of Torino, 10126 Torino, Italy.
Carlo C
CC
Campa
Molecular Biotechnology Center, Department of Molecular Biotechnology and Health Sciences, University of Torino, 10126 Torino, Italy.
Carlotta
C
Costa
Molecular Biotechnology Center, Department of Molecular Biotechnology and Health Sciences, University of Torino, 10126 Torino, Italy.
Jean Piero
JP
Margaria
Molecular Biotechnology Center, Department of Molecular Biotechnology and Health Sciences, University of Torino, 10126 Torino, Italy.
Elisa
E
Ciraolo
Molecular Biotechnology Center, Department of Molecular Biotechnology and Health Sciences, University of Torino, 10126 Torino, Italy.
Miriam
M
Martini
Laboratoire de Parasitologie Moléculaire, Institut de Biologie et de Médecine Moléculaires (IBMM), Université Libre de Bruxelles, Gosselies, 6041 Charleroi, Belgium.
Daniel
D
Monteyne
Molecular Biotechnology Center, Department of Molecular Biotechnology and Health Sciences, University of Torino, 10126 Torino, Italy.
Elisa
E
De Luca
Molecular Biotechnology Center, Department of Molecular Biotechnology and Health Sciences, University of Torino, 10126 Torino, Italy.
Giulia
G
Germena
Leibniz Institut für Molekulare Pharmakologie, 13125 Berlin, Germany.
York
Y
Posor
Centre for Diabetes, Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London E1 2AT, UK.
Tania
T
Maffucci
Molecular Biotechnology Center, Department of Molecular Biotechnology and Health Sciences, University of Torino, 10126 Torino, Italy.
Stefano
S
Marengo
Leibniz Institut für Molekulare Pharmakologie, 13125 Berlin, Germany.
Volker
V
Haucke
Centre for Diabetes, Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London E1 2AT, UK.
Marco
M
Falasca
Laboratoire de Parasitologie Moléculaire, Institut de Biologie et de Médecine Moléculaires (IBMM), Université Libre de Bruxelles, Gosselies, 6041 Charleroi, Belgium; Center for Microscopy and Molecular Imaging-CMMI, Université Libre de Bruxelles, 8 rue Adrienne Bolland, 6041 Gosselies, Belgium.
David
D
Perez-Morga
Division of Genetics and Cell Biology, Dibit San Raffaele Scientific Institute, 20132 Milan, Italy.
Alessandra
A
Boletta
Molecular Biotechnology Center, Department of Molecular Biotechnology and Health Sciences, University of Torino, 10126 Torino, Italy.
Giorgio R
GR
Merlo
Molecular Biotechnology Center, Department of Molecular Biotechnology and Health Sciences, University of Torino, 10126 Torino, Italy. Electronic address: emilio.hirsch@unito.it.
Emilio
E
Hirsch
D000818:Animals; D002465:Cell Movement / Q000502:physiology*; D002478:Cells, Cultured; D002923:Cilia / Q000502:physiology*; D004622:Embryo, Mammalian / Q000166:cytology / Q000378:metabolism; D011992:Endosomes / Q000378:metabolism*; D005260:Female; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D015151:Immunoblotting; D047468:Immunoprecipitation; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D019869:Phosphatidylinositol 3-Kinases / Q000502:physiology*; D018129:Phosphatidylinositol Phosphates / Q000378:metabolism*; D000081082:Phosphoinositide-3 Kinase Inhibitors; D021381:Protein Transport; D034741:RNA, Small Interfering / Q000235:genetics; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism; D011990:Receptors, Transferrin / Q000378:metabolism; D015398:Signal Transduction; D000072086:Smoothened Receptor; D020691:rab GTP-Binding Proteins / Q000378:metabolism*; D000099193:rab11 GTP-Binding Proteins
D019869:Phosphatidylinositol 3-Kinases; D018129:Phosphatidylinositol Phosphates; D000081082:Phosphoinositide-3 Kinase Inhibitors; D034741:RNA, Small Interfering; D043562:Receptors, G-Protein-Coupled; D011990:Receptors, Transferrin; D000072086:Smoothened Receptor; D020691:rab GTP-Binding Proteins; D000099193:rab11 GTP-Binding Proteins; C491022:Smo protein, mouse; C480029:Tfrc protein, mouse; C055525:phosphatidylinositol 3-phosphate; C546635:Pik3c2a protein, mouse