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Magiera K, Tomala M, Kubica K, De Cesare V, Trost M, Zieba BJ, Kachamakova-Trojanowska N, Les M, Dubin G, Holak TA, Skalniak L. Lithocholic Acid Hydroxyamide Destabilizes Cyclin D1 and Induces G 0/G 1 Arrest by Inhibiting Deubiquitinase USP2a. Cell Chem Biol 2017; 24:458-470.e18. [PMID: 28343940 PMCID: PMC5404848 DOI: 10.1016/j.chembiol.2017.03.002] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 09/26/2016] [Accepted: 03/01/2017] [Indexed: 12/29/2022]
Abstract
USP2a is a deubiquitinase responsible for stabilization of cyclin D1, a crucial regulator of cell-cycle progression and a proto-oncoprotein overexpressed in numerous cancer types. Here we report that lithocholic acid (LCA) derivatives are inhibitors of USP proteins, including USP2a. The most potent LCA derivative, LCA hydroxyamide (LCAHA), inhibits USP2a, leading to a significant Akt/GSK3β-independent destabilization of cyclin D1, but does not change the expression of p27. This leads to the defects in cell-cycle progression. As a result, LCAHA inhibits the growth of cyclin D1-expressing, but not cyclin D1-negative cells, independently of the p53 status. We show that LCA derivatives may be considered as future therapeutics for the treatment of cyclin D1-addicted p53-expressing and p53-defective cancer types.
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Affiliation(s)
- Katarzyna Magiera
- Department of Organic Chemistry, Faculty of Chemistry, Jagiellonian University, ul. Ingardena 3, 30-060 Krakow, Poland; Malopolska Centre of Biotechnology, Jagiellonian University, ul. Gronostajowa 7a, 30-387 Krakow, Poland
| | - Marcin Tomala
- Department of Organic Chemistry, Faculty of Chemistry, Jagiellonian University, ul. Ingardena 3, 30-060 Krakow, Poland
| | - Katarzyna Kubica
- Department of Organic Chemistry, Faculty of Chemistry, Jagiellonian University, ul. Ingardena 3, 30-060 Krakow, Poland
| | - Virginia De Cesare
- MRC Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Dundee DD1 5EH, Scotland, UK
| | - Matthias Trost
- MRC Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Dundee DD1 5EH, Scotland, UK
| | - Bartosz J Zieba
- Malopolska Centre of Biotechnology, Jagiellonian University, ul. Gronostajowa 7a, 30-387 Krakow, Poland
| | - Neli Kachamakova-Trojanowska
- Department of Medical Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, ul. Gronostajowa 7, 30-387 Krakow, Poland
| | - Marcin Les
- Department of Organic Chemistry, Faculty of Chemistry, Jagiellonian University, ul. Ingardena 3, 30-060 Krakow, Poland
| | - Grzegorz Dubin
- Malopolska Centre of Biotechnology, Jagiellonian University, ul. Gronostajowa 7a, 30-387 Krakow, Poland; Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, ul. Gronostajowa 7, 30-387 Krakow, Poland
| | - Tad A Holak
- Department of Organic Chemistry, Faculty of Chemistry, Jagiellonian University, ul. Ingardena 3, 30-060 Krakow, Poland; Malopolska Centre of Biotechnology, Jagiellonian University, ul. Gronostajowa 7a, 30-387 Krakow, Poland
| | - Lukasz Skalniak
- Department of Organic Chemistry, Faculty of Chemistry, Jagiellonian University, ul. Ingardena 3, 30-060 Krakow, Poland; Malopolska Centre of Biotechnology, Jagiellonian University, ul. Gronostajowa 7a, 30-387 Krakow, Poland.
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Lakshmikanthan S, Zieba BJ, Ge ZD, Momotani K, Zheng X, Lund H, Artamonov MV, Maas JE, Szabo A, Zhang DX, Auchampach JA, Mattson DL, Somlyo AV, Chrzanowska-Wodnicka M. Rap1b in smooth muscle and endothelium is required for maintenance of vascular tone and normal blood pressure. Arterioscler Thromb Vasc Biol 2014; 34:1486-94. [PMID: 24790136 DOI: 10.1161/atvbaha.114.303678] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
OBJECTIVE Small GTPase Ras-related protein 1 (Rap1b) controls several basic cellular phenomena, and its deletion in mice leads to several cardiovascular defects, including impaired adhesion of blood cells and defective angiogenesis. We found that Rap1b(-/-) mice develop cardiac hypertrophy and hypertension. Therefore, we examined the function of Rap1b in regulation of blood pressure. APPROACH AND RESULTS Rap1b(-/-) mice developed cardiac hypertrophy and elevated blood pressure, but maintained a normal heart rate. Correcting elevated blood pressure with losartan, an angiotensin II type 1 receptor antagonist, alleviated cardiac hypertrophy in Rap1b(-/-) mice, suggesting a possibility that cardiac hypertrophy develops secondary to hypertension. The indices of renal function and plasma renin activity were normal in Rap1b(-/-) mice. Ex vivo, we examined whether the effect of Rap1b deletion on smooth muscle-mediated vessel contraction and endothelium-dependent vessel dilation, 2 major mechanisms controlling basal vascular tone, was the basis for the hypertension. We found increased contractility on stimulation with a thromboxane analog or angiotensin II or phenylephrine along with increased inhibitory phosphorylation of myosin phosphatase under basal conditions consistent with elevated basal tone and the observed hypertension. Cyclic adenosine monophosphate-dependent relaxation in response to Rap1 activator, Epac, was decreased in vessels from Rap1b(-/-) mice. Defective endothelial release of dilatory nitric oxide in response to elevated blood flow leads to hypertension. We found that nitric oxide-dependent vasodilation was significantly inhibited in Rap1b-deficient vessels. CONCLUSIONS This is the first report to indicate that Rap1b in both smooth muscle and endothelium plays a key role in maintaining blood pressure by controlling normal vascular tone.
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Affiliation(s)
- Sribalaji Lakshmikanthan
- From the Blood Research Institute, BloodCenter of Wisconsin, Milwaukee (S.L., M.C.W.); Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville (B.J.Z., K.M., M.V.A., A.V.S.); and Department of Pharmacology and Toxicology (Z.-D.G., J.A.A.), Cardiovascular Center (Z.-D.G., X.Z., J.E.M., D.X.Z., J.A.A.), Department of Medicine (X.Z., J.E.M., D.X.Z.), Department of Physiology (H.L., D.L.M.), and Division of Biostatistics (A.S.), Medical College of Wisconsin, Milwaukee
| | - Bartosz J Zieba
- From the Blood Research Institute, BloodCenter of Wisconsin, Milwaukee (S.L., M.C.W.); Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville (B.J.Z., K.M., M.V.A., A.V.S.); and Department of Pharmacology and Toxicology (Z.-D.G., J.A.A.), Cardiovascular Center (Z.-D.G., X.Z., J.E.M., D.X.Z., J.A.A.), Department of Medicine (X.Z., J.E.M., D.X.Z.), Department of Physiology (H.L., D.L.M.), and Division of Biostatistics (A.S.), Medical College of Wisconsin, Milwaukee
| | - Zhi-Dong Ge
- From the Blood Research Institute, BloodCenter of Wisconsin, Milwaukee (S.L., M.C.W.); Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville (B.J.Z., K.M., M.V.A., A.V.S.); and Department of Pharmacology and Toxicology (Z.-D.G., J.A.A.), Cardiovascular Center (Z.-D.G., X.Z., J.E.M., D.X.Z., J.A.A.), Department of Medicine (X.Z., J.E.M., D.X.Z.), Department of Physiology (H.L., D.L.M.), and Division of Biostatistics (A.S.), Medical College of Wisconsin, Milwaukee
| | - Ko Momotani
- From the Blood Research Institute, BloodCenter of Wisconsin, Milwaukee (S.L., M.C.W.); Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville (B.J.Z., K.M., M.V.A., A.V.S.); and Department of Pharmacology and Toxicology (Z.-D.G., J.A.A.), Cardiovascular Center (Z.-D.G., X.Z., J.E.M., D.X.Z., J.A.A.), Department of Medicine (X.Z., J.E.M., D.X.Z.), Department of Physiology (H.L., D.L.M.), and Division of Biostatistics (A.S.), Medical College of Wisconsin, Milwaukee
| | - Xiaodong Zheng
- From the Blood Research Institute, BloodCenter of Wisconsin, Milwaukee (S.L., M.C.W.); Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville (B.J.Z., K.M., M.V.A., A.V.S.); and Department of Pharmacology and Toxicology (Z.-D.G., J.A.A.), Cardiovascular Center (Z.-D.G., X.Z., J.E.M., D.X.Z., J.A.A.), Department of Medicine (X.Z., J.E.M., D.X.Z.), Department of Physiology (H.L., D.L.M.), and Division of Biostatistics (A.S.), Medical College of Wisconsin, Milwaukee
| | - Hayley Lund
- From the Blood Research Institute, BloodCenter of Wisconsin, Milwaukee (S.L., M.C.W.); Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville (B.J.Z., K.M., M.V.A., A.V.S.); and Department of Pharmacology and Toxicology (Z.-D.G., J.A.A.), Cardiovascular Center (Z.-D.G., X.Z., J.E.M., D.X.Z., J.A.A.), Department of Medicine (X.Z., J.E.M., D.X.Z.), Department of Physiology (H.L., D.L.M.), and Division of Biostatistics (A.S.), Medical College of Wisconsin, Milwaukee
| | - Mykhaylo V Artamonov
- From the Blood Research Institute, BloodCenter of Wisconsin, Milwaukee (S.L., M.C.W.); Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville (B.J.Z., K.M., M.V.A., A.V.S.); and Department of Pharmacology and Toxicology (Z.-D.G., J.A.A.), Cardiovascular Center (Z.-D.G., X.Z., J.E.M., D.X.Z., J.A.A.), Department of Medicine (X.Z., J.E.M., D.X.Z.), Department of Physiology (H.L., D.L.M.), and Division of Biostatistics (A.S.), Medical College of Wisconsin, Milwaukee
| | - Jason E Maas
- From the Blood Research Institute, BloodCenter of Wisconsin, Milwaukee (S.L., M.C.W.); Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville (B.J.Z., K.M., M.V.A., A.V.S.); and Department of Pharmacology and Toxicology (Z.-D.G., J.A.A.), Cardiovascular Center (Z.-D.G., X.Z., J.E.M., D.X.Z., J.A.A.), Department of Medicine (X.Z., J.E.M., D.X.Z.), Department of Physiology (H.L., D.L.M.), and Division of Biostatistics (A.S.), Medical College of Wisconsin, Milwaukee
| | - Aniko Szabo
- From the Blood Research Institute, BloodCenter of Wisconsin, Milwaukee (S.L., M.C.W.); Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville (B.J.Z., K.M., M.V.A., A.V.S.); and Department of Pharmacology and Toxicology (Z.-D.G., J.A.A.), Cardiovascular Center (Z.-D.G., X.Z., J.E.M., D.X.Z., J.A.A.), Department of Medicine (X.Z., J.E.M., D.X.Z.), Department of Physiology (H.L., D.L.M.), and Division of Biostatistics (A.S.), Medical College of Wisconsin, Milwaukee
| | - David X Zhang
- From the Blood Research Institute, BloodCenter of Wisconsin, Milwaukee (S.L., M.C.W.); Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville (B.J.Z., K.M., M.V.A., A.V.S.); and Department of Pharmacology and Toxicology (Z.-D.G., J.A.A.), Cardiovascular Center (Z.-D.G., X.Z., J.E.M., D.X.Z., J.A.A.), Department of Medicine (X.Z., J.E.M., D.X.Z.), Department of Physiology (H.L., D.L.M.), and Division of Biostatistics (A.S.), Medical College of Wisconsin, Milwaukee
| | - John A Auchampach
- From the Blood Research Institute, BloodCenter of Wisconsin, Milwaukee (S.L., M.C.W.); Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville (B.J.Z., K.M., M.V.A., A.V.S.); and Department of Pharmacology and Toxicology (Z.-D.G., J.A.A.), Cardiovascular Center (Z.-D.G., X.Z., J.E.M., D.X.Z., J.A.A.), Department of Medicine (X.Z., J.E.M., D.X.Z.), Department of Physiology (H.L., D.L.M.), and Division of Biostatistics (A.S.), Medical College of Wisconsin, Milwaukee
| | - David L Mattson
- From the Blood Research Institute, BloodCenter of Wisconsin, Milwaukee (S.L., M.C.W.); Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville (B.J.Z., K.M., M.V.A., A.V.S.); and Department of Pharmacology and Toxicology (Z.-D.G., J.A.A.), Cardiovascular Center (Z.-D.G., X.Z., J.E.M., D.X.Z., J.A.A.), Department of Medicine (X.Z., J.E.M., D.X.Z.), Department of Physiology (H.L., D.L.M.), and Division of Biostatistics (A.S.), Medical College of Wisconsin, Milwaukee
| | - Avril V Somlyo
- From the Blood Research Institute, BloodCenter of Wisconsin, Milwaukee (S.L., M.C.W.); Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville (B.J.Z., K.M., M.V.A., A.V.S.); and Department of Pharmacology and Toxicology (Z.-D.G., J.A.A.), Cardiovascular Center (Z.-D.G., X.Z., J.E.M., D.X.Z., J.A.A.), Department of Medicine (X.Z., J.E.M., D.X.Z.), Department of Physiology (H.L., D.L.M.), and Division of Biostatistics (A.S.), Medical College of Wisconsin, Milwaukee
| | - Magdalena Chrzanowska-Wodnicka
- From the Blood Research Institute, BloodCenter of Wisconsin, Milwaukee (S.L., M.C.W.); Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville (B.J.Z., K.M., M.V.A., A.V.S.); and Department of Pharmacology and Toxicology (Z.-D.G., J.A.A.), Cardiovascular Center (Z.-D.G., X.Z., J.E.M., D.X.Z., J.A.A.), Department of Medicine (X.Z., J.E.M., D.X.Z.), Department of Physiology (H.L., D.L.M.), and Division of Biostatistics (A.S.), Medical College of Wisconsin, Milwaukee.
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Carlson DA, Franke AS, Weitzel DH, Speer BL, Hughes PF, Hagerty L, Fortner CN, Veal JM, Barta TE, Zieba BJ, Somlyo AV, Sutherland C, Deng JT, Walsh MP, MacDonald JA, Haystead TAJ. Fluorescence linked enzyme chemoproteomic strategy for discovery of a potent and selective DAPK1 and ZIPK inhibitor. ACS Chem Biol 2013; 8:2715-23. [PMID: 24070067 DOI: 10.1021/cb400407c] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
DAPK1 and ZIPK (also called DAPK3) are closely related serine/threonine protein kinases that regulate programmed cell death and phosphorylation of non-muscle and smooth muscle myosin. We have developed a fluorescence linked enzyme chemoproteomic strategy (FLECS) for the rapid identification of inhibitors for any element of the purinome and identified a selective pyrazolo[3,4-d]pyrimidinone (HS38) that inhibits DAPK1 and ZIPK in an ATP-competitive manner at nanomolar concentrations. In cellular studies, HS38 decreased RLC20 phosphorylation. In ex vivo studies, HS38 decreased contractile force generated in mouse aorta, rabbit ileum, and calyculin A stimulated arterial muscle by decreasing RLC20 and MYPT1 phosphorylation. The inhibitor also promoted relaxation in Ca(2+)-sensitized vessels. A close structural analogue (HS43) with 5-fold lower affinity for ZIPK produced no effect on cells or tissues. These findings are consistent with a mechanism of action wherein HS38 specifically targets ZIPK in smooth muscle. The discovery of HS38 provides a lead scaffold for the development of therapeutic agents for smooth muscle related disorders and a chemical means to probe the function of DAPK1 and ZIPK across species.
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Affiliation(s)
- David A. Carlson
- Department
of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina 27710, United States
| | - Aaron S. Franke
- Department
of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia 22908, United States
| | - Douglas H. Weitzel
- Department
of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina 27710, United States
| | - Brittany L. Speer
- Department
of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina 27710, United States
| | - Philip F. Hughes
- Department
of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina 27710, United States
| | - Laura Hagerty
- Department
of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina 27710, United States
| | - Christopher N. Fortner
- Department
of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina 27710, United States
| | - James M. Veal
- Quanticel
Pharmaceuticals, San Francisco, California 94158, United States
| | - Thomas E. Barta
- Department
of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina 27710, United States
| | - Bartosz J. Zieba
- Department
of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia 22908, United States
| | - Avril V. Somlyo
- Department
of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia 22908, United States
| | - Cindy Sutherland
- Smooth Muscle Research Group at the Libin Cardiovascular Institute of Alberta. Department of Biochemistry & Molecular Biology, University of Calgary, 3280 Hospital Drive NW, Calgary, AB T2N 4Z6, Canada
| | - Jing Ti Deng
- Smooth Muscle Research Group at the Libin Cardiovascular Institute of Alberta. Department of Biochemistry & Molecular Biology, University of Calgary, 3280 Hospital Drive NW, Calgary, AB T2N 4Z6, Canada
| | - Michael P. Walsh
- Smooth Muscle Research Group at the Libin Cardiovascular Institute of Alberta. Department of Biochemistry & Molecular Biology, University of Calgary, 3280 Hospital Drive NW, Calgary, AB T2N 4Z6, Canada
| | - Justin A. MacDonald
- Smooth Muscle Research Group at the Libin Cardiovascular Institute of Alberta. Department of Biochemistry & Molecular Biology, University of Calgary, 3280 Hospital Drive NW, Calgary, AB T2N 4Z6, Canada
| | - Timothy A. J. Haystead
- Department
of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina 27710, United States
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Lakshmikanthan S, Zheng X, Zieba BJ, Nishijima Y, Ge ZD, Momotani K, Lund H, Maas JE, Szabo A, Vasquez-Vivar J, Mattson DL, Auchampach JA, Somlyo AV, Zhang DX, Chrzanowska-Wodnicka M. Abstract 206: Small GTPase Rap1 Transmits Mechanical Signals to Control Vascular Tone and Blood Pressure. Arterioscler Thromb Vasc Biol 2013. [DOI: 10.1161/atvb.33.suppl_1.a206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Smooth muscle (SM)-mediated vessel contraction and endothelium-dependent vessel dilation are major mechanisms controlling basal vascular tone. Increased vascular tone leads to arterial hypertension, a risk factor for cardiovascular diseases. Agonist-induced, Ca2+-dependent SM contraction is modulated by intracellular cAMP, which promotes SM relaxation by inhibition of Rho-mediated myosin regulatory light chain (RLC20) phosphorylation and actomyosin contractility. In response to elevated blood flow, endothelium releases dilator substances that relax vascular SM, and in particular defects in production of nitric oxide (NO) lead to hypertension.
Rap1 is a small GTPase that integrates signals from multiple receptors and two Rap1 isoforms, Rap1a and Rap1b are ubiquitously expressed. We found global Rap1b deletion leads to cardiac hypertrophy and hypertension and examined the effect of Rap1-deficiency on vascular tone. Using SM and endothelium tissue-restricted Rap1 knockout mice we show that deletion of Rap1, via distinct mechanisms in the two tissues, contributes to elevated vascular tone. In SM Rap1 regulates basal contraction level and mediates cAMP-induced desensitization of contraction. Rap1 suppresses RhoA-mediated RLC20 phosphorylation, Ca+2 sensitization and relaxation, signaling that is further enhanced upon cAMP-dependent activation of Rap1 by Rap1 GEF Epac.
In endothelium, we find Rap1 is essential for regulation of NO-dependent vasodilation, as deletion of three of the four Rap1 alleles leads to a significant decrease in NO-dependent vasodilation. Significantly, we find that Rap1 is required for normal shear stress-induced NO release and Rap1-deficency in endothelium leads to elevated blood pressure in mice. Mechanistically, we show that Rap1 is required for transducing signals from the endothelial mechanosensing complex triggering signaling leading to NO production. Because shear stress from flowing blood is the main determinant of NO release, this novel finding positions Rap1 as a key regulator of endothelial function.
In conclusion, Rap1 in SM and endothelium, via distinct mechanisms, plays a key role in maintaining normal vascular tone and blood pressure.
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Affiliation(s)
| | - Xiaodong Zheng
- Dept of Medicine, Med College of Wisconsin, Milwaukee, WI
| | - Bartosz J Zieba
- Dept of Molecular Physiology and Biological Physics, Univ of Virginia, Charlottesville, VA
| | | | - Zhi-Dong Ge
- Dept of Pharmacology and Toxicology, Med College of Wisconsin, Milwaukee, WI
| | - Ko Momotani
- Dept of Molecular Physiology and Biological Physics, Univ of Virginia, Charlottesville, VA
| | - Hayley Lund
- Dept of Physiology, Med College of Wisconsin, Milwaukee, WI
| | - Jason E Maas
- Dept of Pharmacology and Toxicology, Med College of Wisconsin, Milwaukee, WI
| | - Aniko Szabo
- Div of Biostatistics, Med College of Wisconsin, Milwaukee, WI
| | | | | | - John A Auchampach
- Dept of Pharmacology and Toxicology, Med College of Wisconsin, Milwaukee, WI
| | - Avril V Somlyo
- Dept of Molecular Physiology and Biological Physics, Univ of Virginia, Charlottesville, VA
| | - David X Zhang
- Dept of Medicine, Med College of Wisconsin, Milwaukee, WI
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5
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Zieba BJ, Artamonov MV, Jin L, Momotani K, Ho R, Franke AS, Neppl RL, Stevenson AS, Khromov AS, Chrzanowska-Wodnicka M, Somlyo AV. The cAMP-responsive Rap1 guanine nucleotide exchange factor, Epac, induces smooth muscle relaxation by down-regulation of RhoA activity. J Biol Chem 2011; 286:16681-92. [PMID: 21454546 PMCID: PMC3089510 DOI: 10.1074/jbc.m110.205062] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2010] [Revised: 03/11/2011] [Indexed: 11/06/2022] Open
Abstract
Agonist activation of the small GTPase, RhoA, and its effector Rho kinase leads to down-regulation of smooth muscle (SM) myosin light chain phosphatase activity, an increase in myosin light chain (RLC(20)) phosphorylation and force. Cyclic nucleotides can reverse this process. We report a new mechanism of cAMP-mediated relaxation through Epac, a GTP exchange factor for the small GTPase Rap1 resulting in an increase in Rap1 activity and suppression of RhoA activity. An Epac-selective cAMP analog, 8-pCPT-2'-O-Me-cAMP ("007"), significantly reduced agonist-induced contractile force, RLC(20), and myosin light chain phosphatase phosphorylation in both intact and permeabilized vascular, gut, and airway SMs independently of PKA and PKG. The vasodilator PGI(2) analog, cicaprost, increased Rap1 activity and decreased RhoA activity in intact SMs. Forskolin, phosphodiesterase inhibitor isobutylmethylxanthine, and isoproterenol also significantly increased Rap1-GTP in rat aortic SM cells. The PKA inhibitor H89 was without effect on the 007-induced increase in Rap1-GTP. Lysophosphatidic acid-induced RhoA activity was reduced by treatment with 007 in WT but not Rap1B null fibroblasts, consistent with Epac signaling through Rap1B to down-regulate RhoA activity. Isoproterenol-induced increase in Rap1 activity was inhibited by silencing Epac1 in rat aortic SM cells. Evidence is presented that cooperative cAMP activation of PKA and Epac contribute to relaxation of SM. Our findings demonstrate a cAMP-mediated signaling mechanism whereby activation of Epac results in a PKA-independent, Rap1-dependent Ca(2+) desensitization of force in SM through down-regulation of RhoA activity. Cyclic AMP inhibition of RhoA is mediated through activation of both Epac and PKA.
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Affiliation(s)
- Bartosz J. Zieba
- From the Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia 22908
- the Department of Cell Biochemistry, Faculty of Biochemistry, Biophysics, and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
| | - Mykhaylo V. Artamonov
- From the Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia 22908
| | - Li Jin
- From the Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia 22908
| | - Ko Momotani
- From the Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia 22908
| | - Ruoya Ho
- From the Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia 22908
| | - Aaron S. Franke
- From the Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia 22908
| | - Ronald L. Neppl
- the Department of Cardiology, Children's Hospital Boston, Harvard Medical School, Boston, Massachusetts 02115, and
| | - Andra S. Stevenson
- From the Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia 22908
| | - Alexander S. Khromov
- From the Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia 22908
| | | | - Avril V. Somlyo
- From the Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia 22908
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