The long-term objective of this project is to determine newly recognized, specific mechanisms that regulate contraction of vascular, airway and other smooth muscle independently of changes in cellular calcium. The major specific aims are: 1., to determine the mechanism, in vivo kinetics and upstream regulators and downstream effectors through which the Ras family, monomeric GTP-binding protein RhoA sensitizes smooth muscle to calcium by inhibiting the protein phosphatase that de-phosphorylates the regulatory light chain of smooth muscle myosin, an 2., to determine the mechanisms that independently of changes in Ca2+, accelerate dephosphorylation of the regulatory light chain and, thereby, relax smooth muscle.
The specific aims i nclude identification of Rho-related proteins in smooth muscle, the mechanisms through which rho inhibits smooth muscle myosin light chain phosphatase, as well as determining the effects of phosphorylation of telokin and its novel putative role in cyclic GMP- kinase-mediated Ca2+-desensitization. An additional major goal of this project is to relate, in collaborative studies with structural biologists, the function of Rho and Rho-related proteins to their structures as well as the effect of phosphorylation of telokin on its function and crystal structure. The broad, general significance of the project derives from the involvement of RhoA in signalling in, probably, all cell types and the presence and function of the regulatory subunit of smooth muscle myosin phosphatase also in non-muscle cells; the major health related aspects of the research originate from the importance of smooth muscle in regulating the caliber of blood vessels and airways. It is probable that some forms of both hypertension and asthma are due to abnormalities of the regulatory pathways explored in this project that derives special strength from the very close interdisciplinary collaboration of a crystallographer, a molecular biologists and two cell physiologists.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Program Projects (P01)
Project #
5P01HL048807-08
Application #
6327732
Study Section
Project Start
2000-07-01
Project End
2001-06-30
Budget Start
1997-10-01
Budget End
1998-09-30
Support Year
8
Fiscal Year
2000
Total Cost
$187,536
Indirect Cost
Name
University of Virginia
Department
Type
DUNS #
001910777
City
Charlottesville
State
VA
Country
United States
Zip Code
22904
Utepbergenov, Darkhan; Derewenda, Urszula; Olekhnovich, Natalya et al. (2012) Insights into the inhibition of the p90 ribosomal S6 kinase (RSK) by the flavonol glycoside SL0101 from the 1.5 Å crystal structure of the N-terminal domain of RSK2 with bound inhibitor. Biochemistry 51:6499-510
Hoofnagle, Mark H; Neppl, Ronald L; Berzin, Erica L et al. (2011) Myocardin is differentially required for the development of smooth muscle cells and cardiomyocytes. Am J Physiol Heart Circ Physiol 300:H1707-21
Jin, Li; Gan, Qiong; Zieba, Bartosz J et al. (2010) The actin associated protein palladin is important for the early smooth muscle cell differentiation. PLoS One 5:e12823
Khromov, Alexander; Choudhury, Nandini; Stevenson, Andra S et al. (2009) Phosphorylation-dependent autoinhibition of myosin light chain phosphatase accounts for Ca2+ sensitization force of smooth muscle contraction. J Biol Chem 284:21569-79
Jin, Li; Hastings, Nicole E; Blackman, Brett R et al. (2009) Mechanical properties of the extracellular matrix alter expression of smooth muscle protein LPP and its partner palladin; relationship to early atherosclerosis and vascular injury. J Muscle Res Cell Motil 30:41-55
Cierpicki, Tomasz; Bielnicki, Jakub; Zheng, Meiying et al. (2009) The solution structure and dynamics of the DH-PH module of PDZRhoGEF in isolation and in complex with nucleotide-free RhoA. Protein Sci 18:2067-79
Jin, Li; Yoshida, Tadashi; Ho, Ruoya et al. (2009) The actin-associated protein Palladin is required for development of normal contractile properties of smooth muscle cells derived from embryoid bodies. J Biol Chem 284:2121-30
Zheng, Meiying; Cierpicki, Tomasz; Momotani, Ko et al. (2009) On the mechanism of autoinhibition of the RhoA-specific nucleotide exchange factor PDZRhoGEF. BMC Struct Biol 9:36
Jelen, Filip; Lachowicz, Pawel; Apostoluk, Wlodzimierz et al. (2009) Dissecting the thermodynamics of GAP-RhoA interactions. J Struct Biol 165:10-8
Freitas, Maria Regina; Eto, Masumi; Kirkbride, Jason A et al. (2009) Y27632, a Rho-activated kinase inhibitor, normalizes dysregulation in alpha1-adrenergic receptor-induced contraction of Lyon hypertensive rat artery smooth muscle. Fundam Clin Pharmacol 23:169-78

Showing the most recent 10 out of 107 publications