title: cGMP-dependent protein kinase and the regulation of vascular smooth muscle cell gene expression: possible involvement of Elk-1 sumoylation.
abstract: Although the regulation of smooth muscle cell (SMC) gene expression by cGMP-dependent protein kinase (PKG) is now recognized, the mechanisms underlying these effects are not fully understood. In this study, we report that PKG-I stimulates myocardin/serum response factor (SRF)-dependent gene expression in vascular SMCs. The expression of PKG in PKG-deficient cells enhanced myocardin-induced SM22 promoter activity in a concentration-dependent fashion. However, neither SRF nor myocardin expression was affected. To investigate alternative mechanisms, we examined whether PKG affects the phosphorylation of E26-like protein-1 (Elk-1), a SRF/myocardin transcription antagonist. The activation of PKG caused an increase in a higher molecular mass form of phospho-Elk-1 that was determined to be small ubiquitin-related modifier (sumo)ylated Elk-1. PKG increased Elk-1 sumoylation twofold compared with the PKG-deficient cells, and Elk-1 sumoylation was reduced using dominant-negative sumo-conjugating enzyme, DN-Ubc9, confirming PKG-dependent sumoylation of phospho-Elk-1 in vascular SMCs. In addition, PKG stimulated Elk-1 sumoylation in COS-7 cells overexpressing Elk-1, sumo-1, and PKG-I. The increased expression of PKG in vascular SMCs inhibited Elk-1 binding to SMC-specific promoters, SM22 and smooth muscle myosin heavy chain, as measured by EMSA and chromatin immunoprecipitation assay, and PKG suppressed the Elk-1 inhibition of SM22 reporter gene expression. Taken together, these data suggest that PKG-I decreases Elk-1 activity by sumo modification of Elk-1, thereby increasing myocardin-SRF activity on SMC-specific gene expression.
authors.affiliation: Department of Physiology, College of Medicine, University of South Alabama, Mobile, Alabama 36609, USA.
authors.forename: ChungSik
authors.initials: C
authors.lastname: Choi
authors.forename: Hassan
authors.initials: H
authors.lastname: Sellak
authors.forename: Felricia M
authors.initials: FM
authors.lastname: Brown
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Lincoln
mesh_terms: D000818:Animals; D019556:COS Cells; D002478:Cells, Cultured; D002522:Chlorocebus aethiops; D017869:Cyclic GMP-Dependent Protein Kinases / Q000494:pharmacology*; D005786:Gene Expression Regulation / Q000187:drug effects* / Q000502:physiology; D008840:Microfilament Proteins / Q000378:metabolism; D023421:Models, Animal; D009124:Muscle Proteins / Q000378:metabolism; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D009687:Nuclear Proteins / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D015534:Trans-Activators / Q000378:metabolism; D050807:ets-Domain Protein Elk-1 / Q000378:metabolism*; D000099251:Myocardin
chemical_list: D017869:Cyclic GMP-Dependent Protein Kinases; D008840:Microfilament Proteins; D009124:Muscle Proteins; D009687:Nuclear Proteins; D015534:Trans-Activators; D050807:ets-Domain Protein Elk-1; D000099251:Myocardin; C051615:transgelin
references.citation: Cell. 2002 Jan 11;108(1):109-20
references.pmid: 11792325
references.citation: Physiol Rev. 2004 Jul;84(3):767-801
references.pmid: 15269336
references.citation: J Biol Chem. 1989 Jan 15;264(2):1146-55
references.pmid: 2536016
references.citation: Am J Physiol Cell Physiol. 2009 Apr;296(4):C711-23
references.pmid: 19036941
references.citation: Nature. 1995 Jul 13;376(6536):184-8
references.pmid: 7603572
references.citation: EMBO Rep. 2003 Feb;4(2):137-42
references.pmid: 12612601
references.citation: Mol Cell. 2003 Jul;12(1):63-74
references.pmid: 12887893
references.citation: Science. 1999 Nov 19;286(5444):1583-7
references.pmid: 10567269
references.citation: J Clin Invest. 1989 May;83(5):1774-7
references.pmid: 2540223
references.citation: Science. 2007 Sep 7;317(5843):1393-7
references.pmid: 17717153
references.citation: J Biol Chem. 2007 Nov 16;282(46):33367-33380
references.pmid: 17878170
references.citation: Circ Res. 1998 Feb 9;82(2):139-46
references.pmid: 9468184
references.citation: J Cell Sci. 2000 May;113 ( Pt 10):1671-6
references.pmid: 10769198
references.citation: Annu Rev Biochem. 2004;73:355-82
references.pmid: 15189146
references.citation: Proc Natl Acad Sci U S A. 1997 Jul 22;94(15):7862-7
references.pmid: 9223278
references.citation: J Biol Chem. 2006 Feb 17;281(7):4423-33
references.pmid: 16356933
references.citation: Mol Endocrinol. 2008 Mar;22(3):570-84
references.pmid: 18063693
references.citation: J Biol Chem. 1996 Aug 16;271(33):19760-7
references.pmid: 8702682
references.citation: J Biol Chem. 1986 Nov 5;261(31):14740-5
references.pmid: 3533925
references.citation: Semin Cell Dev Biol. 2004 Apr;15(2):201-10
references.pmid: 15209380
references.citation: Physiol Rev. 1979 Jan;59(1):1-61
references.pmid: 108688
references.citation: Methods Enzymol. 2005;399:392-404
references.pmid: 16338371
references.citation: Am J Physiol. 1994 Nov;267(5 Pt 1):C1405-13
references.pmid: 7977701
references.citation: J Mol Cell Cardiol. 2002 Oct;34(10):1345-56
references.pmid: 12392995
references.citation: J Biol Chem. 2006 Mar 31;281(13):8409-16
references.pmid: 16446362
references.citation: EMBO J. 1998 Jun 1;17(11):3045-51
references.pmid: 9606187
references.citation: J Biol Chem. 2004 Jul 30;279(31):32262-8
references.pmid: 15166219
references.citation: J Biol Chem. 2002 Mar 1;277(9):7308-17
references.pmid: 11744740
references.citation: Mol Cell. 2005 Apr 1;18(1):1-12
references.pmid: 15808504
references.citation: J Mol Cell Cardiol. 2003 Jun;35(6):577-93
references.pmid: 12788374
references.citation: Nature. 2004 Mar 11;428(6979):185-9
references.pmid: 15014501
references.citation: Proc Natl Acad Sci U S A. 1994 Sep 27;91(20):9426-30
references.pmid: 7937783
references.citation: Gene. 2004 Jan 7;324:1-14
references.pmid: 14693367
references.citation: Mol Cell Biol. 2005 Nov;25(22):9874-85
references.pmid: 16260603
references.citation: Am J Physiol Cell Physiol. 2004 Jul;287(1):C88-96
references.pmid: 14985234
references.citation: J Cell Biol. 1981 May;89(2):379-83
references.pmid: 7251658
references.citation: J Vasc Res. 1997 Jul-Aug;34(4):245-59
references.pmid: 9256084
references.citation: Physiol Rev. 1995 Jul;75(3):487-517
references.pmid: 7624392
references.citation: J Appl Physiol (1985). 2001 Sep;91(3):1421-30
references.pmid: 11509544
references.citation: Circ Res. 2003 Nov 28;93(11):1034-46
references.pmid: 14645134
references.citation: Mol Cell. 2006 Feb 3;21(3):349-57
references.pmid: 16455490
references.citation: Exp Mol Pathol. 1985 Apr;42(2):139-62
references.pmid: 3884359
references.citation: J Biol Chem. 2005 Jul 1;280(26):24330-8
references.pmid: 15857832
references.citation: J Biol Chem. 1983 Sep 25;258(18):11391-7
references.pmid: 6309846
references.citation: Arterioscler Thromb Vasc Biol. 2007 Jan;27(1):42-8
references.pmid: 17082491
references.citation: J Biol Chem. 2004 Aug 13;279(33):34496-504
references.pmid: 15194681
references.citation: J Cell Biol. 2004 Jun 21;165(6):767-73
references.pmid: 15210726
references.citation: Methods Mol Biol. 2009;497:141-52
references.pmid: 19107415
references.citation: Hypertension. 1996 Mar;27(3 Pt 2):552-7
references.pmid: 8613202
references.citation: Trends Biochem Sci. 2003 Nov;28(11):612-8
references.pmid: 14607092
references.citation: Proc Natl Acad Sci U S A. 2003 Aug 5;100(16):9366-70
references.pmid: 12867591
references.citation: Proc Natl Acad Sci U S A. 2006 Jan 3;103(1):45-50
references.pmid: 16371476
references.citation: J Vasc Res. 2002 Mar-Apr;39(2):95-103
references.pmid: 12011581
references.citation: Am J Physiol Lung Cell Mol Physiol. 2009 May;296(5):L780-9
references.pmid: 19251841
references.citation: Mol Cell Biol. 2003 Apr;23(8):2953-68
references.pmid: 12665592
references.citation: J Vasc Res. 1994 Nov-Dec;31(6):330-7
references.pmid: 7986957
references.citation: Front Biosci. 2006 Jan 01;11:356-67
references.pmid: 16146737
references.citation: Mol Cell Biol. 2003 Apr;23(7):2425-37
references.pmid: 12640126
references.citation: J Clin Invest. 2001 Apr;107(7):823-34
references.pmid: 11285301
references.citation: J Biol Chem. 2006 Mar 17;281(11):6977-84
references.pmid: 16407222