Regulation of Myosin Light Chain Phosphorylation

  • Yuansheng Gao


The interaction of myosin and actin constitutes the basic mechanism of muscle contractile activity. In smooth muscle cells (SMCs) including vascular smooth muscle cells, this interaction is predominantly regulated by the phosphorylation of the regulatory light chain (RLC) of myosin. The RLC is phosphorylated by myosin light chain kinase (MLCK) and dephosphorylated by myosin light chain phosphatase (MLCP). Therefore, the contractility of SMCs is determined by the relative ratio of the activity of MLCK vs. that of MLCP. During a contractile response, MLCK is activated by calmodulin-bound Ca2+. Meanwhile the activity of MLCP is suppressed by protein kinase C (PKC) through the 17-kDa PKC-potentiated inhibitor protein (CPI-17) and by Rho kinase (ROCK). The varied activities of these major signaling pathways endow SMCs with different contractile profiles such as phasic and tonic contractions to meet the diversified physiological requirements.


MLCK MLCP MYPT1 PKC CPI-17 RhoA Rho kinase 


  1. Brozovich FV, Nicholson CJ, Degen CV, Gao YZ, Aggarwal M, Morgan KG (2016) Mechanisms of vascular smooth muscle contraction and the basis for pharmacologic treatment of smooth muscle disorders. Pharmacol Rev 68:476–532CrossRefPubMedPubMedCentralGoogle Scholar
  2. Butler T, Paul J, Europe-Finner N, Smith R, Chan EC (2013) Role of serine-threonine phosphoprotein phosphatases in smooth muscle contractility. Am J Physiol Cell Physiol 304:C485–C504CrossRefPubMedGoogle Scholar
  3. Chen Z, Zhang X, Ying L, Dou D, Li Y, Bai Y, Liu J, Liu L, Feng H, Yu X, Leung SWS, Vanhoutte PM, Gao Y (2014) Cyclic IMP-synthesized by sGC as a mediator of hypoxic contraction of coronary arteries. Am J Physiol Heart Circ Physiol 307:H328–H336CrossRefPubMedGoogle Scholar
  4. Cherfils J, Zeghouf M (2013) Regulation of small GTPases by GEFs, GAPs, and GDIs. Physiol Rev 93:269–309CrossRefPubMedGoogle Scholar
  5. Dimopoulos GJ, Semba S, Kitazawa K, Eto M, Kitazawa T (2007) Ca2+-dependent rapid Ca2+ sensitization of contraction in arterial smooth muscle. Circ Res 100:121–129CrossRefPubMedGoogle Scholar
  6. Eddinger TJ, Meer DP (2007) Myosin II isoforms in smooth muscle: heterogeneity and function. Am J Physiol Cell Physiol 293:C493–C508CrossRefPubMedGoogle Scholar
  7. El-Yazbi AF, Johnson RP, Walsh EJ, Takeya K, Walsh MP, Cole WC (2010) Pressure-dependent contribution of rho kinase-mediated calcium sensitization in serotonin-evoked vasoconstriction of rat cerebral arteries. J Physiol 588:1747–1762CrossRefPubMedPubMedCentralGoogle Scholar
  8. Eto M (2009) Regulation of cellular protein phosphatase-1 (PP1) by phosphorylation of the CPI-17 family, C-kinase-activated PP1 inhibitors. J Biol Chem 284:35273–35277CrossRefPubMedPubMedCentralGoogle Scholar
  9. Eto M, Brautigan DL (2012) Endogenous inhibitor proteins that connect Ser/Thr kinases and phosphatases in cell signaling. IUBMB Life 64:732–739CrossRefPubMedPubMedCentralGoogle Scholar
  10. Fisher SA, Ikebe M (1995) Developmental and tissue distribution of expression of nonmuscle and smooth muscle isoforms of myosin light chain kinase. Biochem Biophys Res Commun 217:696–703CrossRefPubMedGoogle Scholar
  11. Freeley M, Kelleher D, Long A (2011) Regulation of Protein Kinase C function by phosphorylation on conserved and non-conserved sites. Cell Signal 23:753–762CrossRefPubMedGoogle Scholar
  12. Gabet AS, Coulon S, Fricot A, Vandekerckhove J, Chang Y, Ribeil JA, Lordier L, Zermati Y, Asnafi V, Belaid Z, Debili N, Vainchenker W, Varet B, Hermine O, Courtois G (2011) Caspase-activated ROCK-1 allows erythroblast terminal maturation independently of cytokine-induced Rho signaling. Cell Death Differ 18:678–689CrossRefPubMedGoogle Scholar
  13. Gallagher PJ, Herring BP, Stull JT (1997) Myosin light chain kinases. J Muscle Res Cell Motil 18:1–16CrossRefPubMedGoogle Scholar
  14. Gao N, Huang J, He W, Zhu M, Kamm KE, Stull JT (2013) Signaling through myosin light chain kinase in smooth muscles. J Biol Chem 288:7596–7605CrossRefPubMedPubMedCentralGoogle Scholar
  15. Grassie ME, Moffat LD, Walsh MP, MacDonald JA (2011) The myosin phosphatase targeting protein (MYPT) family: a regulated mechanism for achieving substrate specificity of the catalytic subunit of protein phosphatase type 1δ. Arch Biochem Biophys 510:147–159CrossRefPubMedGoogle Scholar
  16. Hartmann S, Ridley AJ, Lutz S (2015) The function of rho-associated kinases ROCK1 and ROCK2 in the pathogenesis of cardiovascular disease. Front Pharmacol 6:276CrossRefPubMedPubMedCentralGoogle Scholar
  17. Heissler SM, Sellers JR (2016) Various themes of myosin regulation. J Mol Biol 428:1927–1946CrossRefPubMedPubMedCentralGoogle Scholar
  18. Hong F, Haldeman BD, Jackson D, Carter M, Baker JE, Cremo CR (2011) Biochemistry of smooth muscle myosin light chain kinase. Arch Biochem Biophys 510:135–146CrossRefPubMedPubMedCentralGoogle Scholar
  19. Hong F, Brizendine RK, Carter MS, Alcala DB, Brown AE, Chattin AM, Haldeman BD, Walsh MP, Facemyer KC, Baker JE, Cremo CR (2015) Diffusion of myosin light chain kinase on actin: a mechanism to enhance myosin phosphorylation rates in smooth muscle. J Gen Physiol 146:267–280CrossRefPubMedPubMedCentralGoogle Scholar
  20. Igumenova TI (2015) Dynamics and membrane interactions of protein kinase C. Biochemistry 54:4953–4968CrossRefPubMedPubMedCentralGoogle Scholar
  21. Johnson RP, El-Yazbi AF, Takeya K, Walsh EJ, Walsh MP, Cole WC (2009) Ca2+ sensitization via phosphorylation of myosin phosphatase targeting subunit at threonine-855 by Rho kinase contributes to the arterial myogenic response. J Physiol 587:2537–2553CrossRefPubMedPubMedCentralGoogle Scholar
  22. Kamm KE, Stull JT (2011) Signaling to myosin regulatory light chain in sarcomeres. J Biol Chem 286:9941–9947CrossRefPubMedPubMedCentralGoogle Scholar
  23. Kaneko T, Amano M, Maeda A, Goto H, Takahashi K, Ito M, Kaibuchi K (2000) Identification of calponin as a novel substrate of rho-kinase. Biochem Biophys Res Commun 273(1): 110–116CrossRefPubMedGoogle Scholar
  24. Kang JH, Asai D, Tsuchiya A, Mori T, Niidome T, Katayama Y (2011) Peptide substrates for rho-associated kinase 2 (rho-kinase 2/ROCK2). PLoS One 6:e22699CrossRefPubMedPubMedCentralGoogle Scholar
  25. Khasnis M, Nakatomi A, Gumpper K, Eto M (2014) Reconstituted human myosin light chain phosphatase reveals distinct roles of two inhibitory phosphorylation sites of the regulatory subunit, MYPT1. Biochemistry 53:2701–2709CrossRefPubMedPubMedCentralGoogle Scholar
  26. Loirand G, Pacaud P (2010) The role of rho protein signaling in hypertension. Nat Rev Cardiol 7:637–647CrossRefPubMedGoogle Scholar
  27. Månsson A, Rassier D, Tsiavaliaris G (2015) Poorly understood aspects of striated muscle contraction. Biomed Res Int 2015:245154CrossRefPubMedPubMedCentralGoogle Scholar
  28. Nagaoka T, Morio Y, Casanova N, Bauer N, Gebb S, McMurtry I, Oka M (2004) Rho/Rho kinase signaling mediates increased basal pulmonary vascular tone in chronically hypoxic rats. Am J Physiol Lung Cell Mol Physiol 287:L665–L672CrossRefPubMedGoogle Scholar
  29. Pfitzer G (2001) Rregulation of myosin phosphorylation in smooth muscle. J Appl Physiol 91:497–503PubMedGoogle Scholar
  30. Reho JJ, Zheng X, Fisher SA (2014) Smooth muscle contractile diversity in the control of regional circulations. Am J Physiol Heart Circ Physiol 306:H163–H172CrossRefPubMedGoogle Scholar
  31. Riento K, Guasch RM, Garg R, Jin B, Ridley AJ (2003) RhoE binds to ROCK I and inhibits downstream signaling. Mol Cell Biol 23:4219–4229CrossRefPubMedPubMedCentralGoogle Scholar
  32. Salamanca DA, Khalil RA (2005) Protein kinase C isoforms as specific targets for modulation of vascular smooth muscle function in hypertension. Biochem Pharmacol 70:1537–1547CrossRefPubMedPubMedCentralGoogle Scholar
  33. Sebbagh M, Hamelin J, Bertoglio J, Solary E, Bréard J (2005) Direct cleavage of ROCK II by granzyme B induces target cell membrane blebbing in a caspase-independent manner. J Exp Med 201:465–471CrossRefPubMedPubMedCentralGoogle Scholar
  34. Shi Y (2009) Serine/threonine phosphatases: mechanism through structure. Cell 139:468–484CrossRefPubMedGoogle Scholar
  35. Shimokawa H, Sunamura S, Satoh K (2016) RhoA/Rho-Kinase in the cardiovascular system. Circ Res 118:352–366CrossRefPubMedGoogle Scholar
  36. Sun YB, Irving M (2010) The molecular basis of the steep force-calcium relation in heart muscle. J Mol Cell Cardiol 48:859–865CrossRefPubMedPubMedCentralGoogle Scholar
  37. Takashima S (2009) Phosphorylation of myosin regulatory light chain by myosin light chain kinase, and muscle contraction. Circ J 73:208–213CrossRefPubMedGoogle Scholar
  38. Taylor KA, Feig M, Brooks CL 3rd, Fagnant PM, Lowey S, Trybus KM (2014) Role of the essential light chain in the activation of smooth muscle myosin by regulatory light chain phosphorylation. J Struct Biol 185:375–382CrossRefPubMedGoogle Scholar
  39. Tobias IS, Newton AC (2016) Protein scaffolds control localized protein kinase Cζ activity. J Biol Chem 291:13809–13822CrossRefPubMedGoogle Scholar
  40. Tourneux P, Chester M, Grover T, Abman SH (2008) Fasudil inhibits the myogenic response in the fetal pulmonary circulation. Am J Physiol Heart Circ Physiol 295:H1505–H1513CrossRefPubMedPubMedCentralGoogle Scholar
  41. Wendt T, Taylor D, Messier T, Trybus KM, Taylor KA (1999) Visualization of head-head interactions in the inhibited state of smooth muscle myosin. J Cell Biol 147:1385–1390CrossRefPubMedPubMedCentralGoogle Scholar
  42. Wilson DP, Susnjar M, Kiss E, Sutherland C, Walsh MP (2005) Thromboxane A2-induced contraction of rat caudal arterial smooth muscle involves activation of Ca2+ entry and Ca2+ sensitization: Rho-associated kinase-mediated phosphorylation of MYPT1 at Thr-855, but not Thr-697. Biochem J 389:763–774CrossRefPubMedPubMedCentralGoogle Scholar
  43. Woodsome TP, Eto M, Everett A, Brautigan DL, Kitazawa T (2001) Expression of CPI-17 and myosin phosphatase correlates with Ca2+ sensitivity of protein kinase C-induced contraction in rabbit smooth muscle. J Physiol 535:553–564CrossRefPubMedPubMedCentralGoogle Scholar
  44. Wu-Zhang AX, Newton AC (2013) Protein kinase C pharmacology: refining the toolbox. Biochem J 452:195–209CrossRefPubMedPubMedCentralGoogle Scholar

Copyright information

© Springer Nature Singapore Pte Ltd. 2017

Authors and Affiliations

  • Yuansheng Gao
    • 1
  1. 1.Department of Physiology and PathophysiologyPeking University Health Science CenterBeijingChina

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