This Article Full Text Full Text (PDF) Data Supplement All Versions of this Article: 97/6/541    most recent 01.RES.0000182630.29093.0dv1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Marganski, W. A. Articles by Morgan, K. G. Search for Related Content PubMed PubMed Citation Articles by Marganski, W. A. Articles by Morgan, K. G. Pubmed/NCBI databases Substance via MeSH Related Collections Cell biology/structural biology Cell signalling/signal transduction Other Vascular biology

(Circulation Research. 2005;97:541.)
© 2005 American Heart Association, Inc.

Molecular Medicine

Targeting of a Novel Ca+²/Calmodulin-Dependent Protein Kinase II Is Essential for Extracellular Signal-Regulated Kinase–Mediated Signaling in Differentiated Smooth Muscle Cells

William A. Marganski, Samudra S. Gangopadhyay, Hyun-Dong Je, Cynthia Gallant, Kathleen G. Morgan

From the Boston Biomedical Research Institute (W.A.M., S.S.G., H.-D.J., C.G., K.G.M.), Watertown; and the Department of Medicine (K.G.M.), Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Mass.

Correspondence to Kathleen G. Morgan, PhD, Boston Biomedical Research Institute, 64 Grove St, Watertown, MA 02472. E-mail morgan{at}bbri.org

Subcellular targeting of kinases controls their activation and access to substrates. Although Ca²⁺/calmodulin-dependent protein kinase II (CaMKII) is known to regulate differentiated smooth muscle cell (dSMC) contractility, the importance of targeting in this regulation is not clear. The present study investigated the function in dSMCs of a novel variant of the isoform of CaMKII that contains a potential targeting sequence in its association domain (CaMKII G-2). Antisense knockdown of CaMKII G-2 inhibited extracellular signal-related kinase (ERK) activation, myosin phosphorylation, and contractile force in dSMCs. Confocal colocalization analysis revealed that in unstimulated dSMCs CaMKII G-2 is bound to a cytoskeletal scaffold consisting of interconnected vimentin intermediate filaments and cytosolic dense bodies. On activation with a depolarizing stimulus, CaMKII G-2 is released into the cytosol and subsequently targeted to cortical dense plaques. Comparison of phosphorylation and translocation time courses indicates that, after CaMKII G-2 activation, and before CaMKII G-2 translocation, vimentin is phosphorylated at a CaMKII-specific site. Differential centrifugation demonstrated that phosphorylation of vimentin in dSMCs is not sufficient to cause its disassembly, in contrast to results in cultured cells. Loading dSMCs with a decoy peptide containing the polyproline sequence within the association domain of CaMKII G-2 inhibited targeting. Furthermore, prevention of CaMKII G-2 targeting led to significant inhibition of ERK activation as well as contractility. Thus, for the first time, this study demonstrates the importance of CaMKII targeting in dSMC signaling and identifies a novel targeting function for the association domain in addition to its known role in oligomerization.

Key Words: CaMKII • smooth muscle • contractility • targeting • extracellular signal-regulated kinase

This article has been cited by other articles:

				S. S. Gangopadhyay, E. Kengni, S. Appel, C. Gallant, H. R. Kim, P. Leavis, J. DeGnore, and K. G. Morgan Smooth Muscle Archvillin Is an ERK Scaffolding Protein J. Biol. Chem., June 26, 2009; 284(26): 17607 - 17615. [Abstract] [Full Text] [PDF]

				D. D. Tang p130 Crk-Associated Substrate (CAS) in Vascular Smooth Muscle Journal of Cardiovascular Pharmacology and Therapeutics, June 1, 2009; 14(2): 89 - 98. [Abstract] [PDF]

				H. R. Kim, C. Gallant, P. C. Leavis, S. J. Gunst, and K. G. Morgan Cytoskeletal remodeling in differentiated vascular smooth muscle is actin isoform dependent and stimulus dependent Am J Physiol Cell Physiol, September 1, 2008; 295(3): C768 - C778. [Abstract] [Full Text] [PDF]

				M. Z. Mercure, R. Ginnan, and H. A. Singer CaM kinase II{delta}2-dependent regulation of vascular smooth muscle cell polarization and migration Am J Physiol Cell Physiol, June 1, 2008; 294(6): C1465 - C1475. [Abstract] [Full Text] [PDF]

				C.-W. Lee, C.-C. Lin, S.-F. Luo, H.-C. Lee, I.-T. Lee, W. C. Aird, T.-L. Hwang, and C.-M. Yang Tumor Necrosis Factor-{alpha} Enhances Neutrophil Adhesiveness: Induction of Vascular Cell Adhesion Molecule-1 via Activation of Akt and CaM Kinase II and Modifications of Histone Acetyltransferase and Histone Deacetylase 4 in Human Tracheal Smooth Muscle Cells Mol. Pharmacol., May 1, 2008; 73(5): 1454 - 1464. [Abstract] [Full Text] [PDF]

				D. D. Tang Intermediate filaments in smooth muscle Am J Physiol Cell Physiol, April 1, 2008; 294(4): C869 - C878. [Abstract] [Full Text] [PDF]

				S. J. House and H. A. Singer CaMKII-{delta} Isoform Regulation of Neointima Formation After Vascular Injury Arterioscler. Thromb. Vasc. Biol., March 1, 2008; 28(3): 441 - 447. [Abstract] [Full Text] [PDF]

				Y. Anfinogenova, R. Wang, Q.-f. Li, A. M. Spinelli, and D. D. Tang Abl Silencing Inhibits CAS-Mediated Process and Constriction in Resistance Arteries Circ. Res., August 17, 2007; 101(4): 420 - 428. [Abstract] [Full Text] [PDF]

				S. J. House, R. G. Ginnan, S. E. Armstrong, and H. A. Singer Calcium/calmodulin-dependent protein kinase II-{delta} isoform regulation of vascular smooth muscle cell proliferation Am J Physiol Cell Physiol, June 1, 2007; 292(6): C2276 - C2287. [Abstract] [Full Text] [PDF]

				R. J. Jones, D. Jourd'heuil, J. C. Salerno, S. M. E. Smith, and H. A. Singer iNOS regulation by calcium/calmodulin-dependent protein kinase II in vascular smooth muscle Am J Physiol Heart Circ Physiol, June 1, 2007; 292(6): H2634 - H2642. [Abstract] [Full Text] [PDF]

				R. Wang, Q.-F. Li, Y. Anfinogenova, and D. D. Tang Dissociation of Crk-associated substrate from the vimentin network is regulated by p21-activated kinase on ACh activation of airway smooth muscle Am J Physiol Lung Cell Mol Physiol, January 1, 2007; 292(1): L240 - L248. [Abstract] [Full Text] [PDF]

				Q.-F. Li, A. M. Spinelli, R. Wang, Y. Anfinogenova, H. A. Singer, and D. D. Tang Critical Role of Vimentin Phosphorylation at Ser-56 by p21-activated Kinase in Vimentin Cytoskeleton Signaling J. Biol. Chem., November 10, 2006; 281(45): 34716 - 34724. [Abstract] [Full Text] [PDF]

				R. Wang, Q. Li, and D. D. Tang Role of vimentin in smooth muscle force development Am J Physiol Cell Physiol, September 1, 2006; 291(3): C483 - C489. [Abstract] [Full Text] [PDF]