title: Hyperphosphorylation of polycystin-2 at a critical residue in disease reveals an essential role for polycystin-1-regulated dephosphorylation.
abstract: Mutations in PKD1 (85%) or PKD2 (15%) account for almost all cases of autosomal dominant polycystic kidney disease (ADPKD). The ADPKD proteins, termed as polycystin-1 (PC1) and polycystin-2 (PC2), interact via their C-termini to form a receptor-ion channel complex whose function and regulation are not fully understood. Here, we report the first phosphorylated residue (Ser(829)) in PC2, whose dephosphorylation is mediated by PC1 binding through the recruitment of protein phosphatase-1 alpha (PP1α). Using a new phosphospecific antibody (pPC2) to this site, we demonstrate that Ser(829) is phosphorylated by Protein kinase A (PKA) but remains constitutively phosphorylated in cells and tissues lacking PC1. cAMP increased pSer(829) basolateral localization in MDCK cells in a time dependent manner and was essential for pronephric development in Xenopus embryos. When constitutively expressed, a complex phenotype associated with enhanced ATP-dependent ER Ca(2+) release and loss of growth suppression was observed in cycling cells. These results reveal a reciprocal functional link between PC1 and PC2 which is critically dependent on their interaction. Unopposed cAMP stimulated hyperphosphorylation of PC2 in the absence of functional PC1 could contribute to cyst initiation in PKD1 patients and represents a new molecular paradigm in understanding ADPKD pathogenesis.
authors: Kidney Genetics Group, Academic Nephrology Unit, Henry Wellcome Laboratories for Medical Research,University of Sheffield Medical School, Sheffield, UK.
authors: Andrew J
authors: AJ
authors: Streets
authors: Oliver
authors: O
authors: Wessely
authors: Dorien J M
authors: DJ
authors: Peters
authors: Albert C M
authors: AC
authors: Ong
mesh_terms: D000818:Animals; D000242:Cyclic AMP / Q000235:genetics / Q000378:metabolism*; D017868:Cyclic AMP-Dependent Protein Kinases / Q000235:genetics / Q000378:metabolism*; D004285:Dogs; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D061985:Madin Darby Canine Kidney Cells; D051379:Mice; D018345:Mice, Knockout; D009154:Mutation; D010766:Phosphorylation / Q000502:physiology; D016891:Polycystic Kidney, Autosomal Dominant / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D054645:Protein Phosphatase 1 / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D050396:TRPP Cation Channels / Q000235:genetics / Q000378:metabolism*; D014982:Xenopus laevis
chemical_list: D000242:Cyclic AMP; D017868:Cyclic AMP-Dependent Protein Kinases; D054645:Protein Phosphatase 1; D050396:TRPP Cation Channels
references: J Am Soc Nephrol. 2009 Feb;20(2):278-88
references: 19158352
references: J Cell Sci. 2002 Jan 15;115(Pt 2):241-56
references: 11839776
references: EMBO J. 2008 May 7;27(9):1345-56
references: 18388856
references: Cell. 2002 Apr 19;109(2):157-68
references: 12007403
references: J Clin Invest. 1999 Mar;103(6):761-5
references: 10079095
references: J Biol Chem. 2004 Jul 9;279(28):29728-39
references: 15123714
references: Proc Natl Acad Sci U S A. 2009 Jul 14;106(28):11558-63
references: 19556541
references: Cell Calcium. 2012 Jun;51(6):452-8
references: 22456092
references: J Biol Chem. 2009 Dec 25;284(52):36431-36441
references: 19854836
references: Kidney Int. 2012 Jan;81(1):76-85
references: 21900881
references: Lancet. 2007 Apr 14;369(9569):1287-1301
references: 17434405
references: Traffic. 2006 Mar;7(3):337-53
references: 16497227
references: J Biol Chem. 1997 May 23;272(21):13856-63
references: 9153244
references: Proc Natl Acad Sci U S A. 2007 Feb 13;104(7):2199-204
references: 17287340
references: Nat Genet. 2003 Feb;33(2):129-37
references: 12514735
references: J Am Soc Nephrol. 2012 May;23(5):842-53
references: 22343118
references: Science. 2011 Jun 10;332(6035):1322-6
references: 21659605
references: J Biol Chem. 2002 Jun 7;277(23):20763-73
references: 11901144
references: J Biol Chem. 2004 May 7;279(19):19987-95
references: 14742446
references: Hum Mutat. 2009 Feb;30(2):264-73
references: 18837007
references: Chem Biol. 2009 Apr 24;16(4):365-71
references: 19389623
references: J Cell Sci. 2009 May 1;122(Pt 9):1410-7
references: 19351715
references: EMBO J. 2010 Apr 7;29(7):1176-91
references: 20168298
references: J Cell Biol. 2011 Jun 13;193(6):1021-32
references: 21670214
references: Kidney Int. 2007 Jul;72(2):157-65
references: 17396115
references: J Cell Biol. 2004 Aug 30;166(5):637-43
references: 15337773
references: Hum Mol Genet. 2003 Aug 1;12(15):1875-80
references: 12874107
references: Hum Mol Genet. 2008 Apr 15;17(8):1109-19
references: 18178578
references: Am J Physiol Cell Physiol. 2004 Jun;286(6):C1264-70
references: 14749217
references: Nat Cell Biol. 2005 Dec;7(12):1202-12
references: 16311606
references: Science. 2011 Jun 10;332(6035):1317-22
references: 21659604
references: J Cell Biol. 2005 Oct 10;171(1):47-59
references: 16216922
references: J Biol Chem. 2008 Oct 17;283(42):28471-9
references: 18701462
references: Hum Mol Genet. 2006 May 1;15(9):1465-73
references: 16551655
references: Mol Cell Proteomics. 2009 Aug;8(8):1839-49
references: 19366988
references: J Biol Chem. 2011 May 27;286(21):18994-9000
references: 21474446
references: Am J Pathol. 1999 Jun;154(6):1721-9
references: 10362797
references: Development. 2010 Apr;137(7):1107-16
references: 20215348
references: Dev Biol. 2007 Jul 1;307(1):152-64
references: 17521625
references: Cell. 2010 Dec 23;143(7):1174-89
references: 21183079
references: Proc Natl Acad Sci U S A. 2006 May 2;103(18):7159-64
references: 16641100
references: Cell. 2006 Nov 3;127(3):635-48
references: 17081983
references: Proc Natl Acad Sci U S A. 2011 Jun 28;108(26):10679-84
references: 21670265
references: Kidney Int. 2005 Apr;67(4):1234-47
references: 15780076
references: Exp Nephrol. 2000 Jul-Oct;8(4-5):208-14
references: 10940718
references: EMBO J. 2005 Feb 23;24(4):705-16
references: 15692563
references: Curr Biol. 1999 Mar 25;9(6):321-4
references: 10209101
references: J Biol Chem. 2006 Jan 6;281(1):137-44
references: 16278216
references: Mol Biol Cell. 2010 Nov 15;21(22):3853-65
references: 20881056
references: J Proteome Res. 2008 Dec;7(12):5314-26
references: 19367708
references: Eur J Hum Genet. 2004 Jun;12(6):433-40
references: 15054393
references: Kidney Int. 1999 Oct;56(4):1324-33
references: 10504485
references: Hum Mol Genet. 2000 Jul 1;9(11):1641-9
references: 10861291
references: Kidney Int. 2004 Sep;66(3):1283-5
references: 15327429
references: J Am Soc Nephrol. 2003 Jul;14(7):1804-15
references: 12819240
references: J Biol Chem. 2010 Jun 11;285(24):18794-805
references: 20375013
references: PLoS One. 2012;7(6):e36798
references: 22675472
references: Biochem Biophys Res Commun. 2001 Sep 21;287(2):328-31
references: 11554729