The long-term goal of this project is to improve our understanding of the cellular and molecular regulation mechanisms of mucociliary clearance, an important host defense mechanism of the lung. Ciliary activity is an integral part of mucociliary clearance and changes in ciliary beat frequency (CBF) are often associated with similar changes in mucociliary transport. This application focuses on how two widely recognized second messengers in cell signaling, cAMP and calcium ([Ca2+]i), regulate CBF. cAMP has been shown to increase CBF through a cAMP-dependent kinase-mediated event, possibly by phosphorylating a ciliary protein designated p26. Increasing [Ca2+]i also stimulates CBF, likely through a ciliary Ca2+-binding protein. Because both second messengers increase CBF, the question arises whether these signaling pathways regulate CBF through independent signal transduction cascades or whether the pathways converge at some level to affect a common target prior to dynein/microtubule interaction. Evidence suggests that they converge because elevations in cAMP render CBF less sensitive to [Ca2+]1 changes. The simplest hypothesis to explain this phenomenon is that the cAMP and Ca2+ signaling pathways converge onto a single ciliary protein (p26) or protein complex (containing p26), which regulates CBF. The phosphorylation of this target changes its Ca - affinity or off-rate. This proposal seeks to explore the identity and function of p26 and begin to examine interactions between p26 and the Ca2+ pathway.
The specific aims are: 1. To characterize p26 and localize it within the cilium. 2. To identify a calcium-binding protein on outer dynein arms 3. To evaluate the correlation between PKA-mediated phosphorylation of p26 and increases in CBF as well as p26 phosphorylation and altered Ca2+/CBF coupling. 4. To evaluate a cause-effect relationship between p26 phosphorylation and CBF changes. The results of these studies will provide new and important information on the role of specific ciliary proteins in regulating mammalian CBF. In addition, the exploration of signaling crosstalk may have important implications in other cell types that regulate some form of cell motility.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL060644-02
Application #
6184535
Study Section
Lung Biology and Pathology Study Section (LBPA)
Project Start
1999-07-01
Project End
2003-06-30
Budget Start
2000-07-01
Budget End
2001-06-30
Support Year
2
Fiscal Year
2000
Total Cost
$236,144
Indirect Cost
Name
University of Miami School of Medicine
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
City
Miami
State
FL
Country
United States
Zip Code
33146
Krick, Stefanie; Wang, Junjie; St-Pierre, Melissa et al. (2016) Dual Oxidase 2 (Duox2) Regulates Pannexin 1-mediated ATP Release in Primary Human Airway Epithelial Cells via Changes in Intracellular pH and Not H2O2 Production. J Biol Chem 291:6423-32
Unwalla, Hoshang J; Ivonnet, Pedro; Dennis, John S et al. (2015) Transforming growth factor-?1 and cigarette smoke inhibit the ability of ?2-agonists to enhance epithelial permeability. Am J Respir Cell Mol Biol 52:65-74
Cancado, Jose E; Mendes, Eliana S; Arana, Johana et al. (2015) Effect of airway acidosis and alkalosis on airway vascular smooth muscle responsiveness to albuterol. BMC Pharmacol Toxicol 16:9
Ivonnet, P; Salathe, M; Conner, G E (2015) Hydrogen peroxide stimulation of CFTR reveals an Epac-mediated, soluble AC-dependent cAMP amplification pathway common to GPCR signalling. Br J Pharmacol 172:173-84
Schmid, Andreas; Meili, Dimirela; Salathe, Matthias (2014) Soluble adenylyl cyclase in health and disease. Biochim Biophys Acta 1842:2584-92
Gerovac, Benjamin J; Valencia, Monica; Baumlin, Nathalie et al. (2014) Submersion and hypoxia inhibit ciliated cell differentiation in a notch-dependent manner. Am J Respir Cell Mol Biol 51:516-25
Chen, Xi; Baumlin, Nathalie; Buck, Jochen et al. (2014) A soluble adenylyl cyclase form targets to axonemes and rescues beat regulation in soluble adenylyl cyclase knockout mice. Am J Respir Cell Mol Biol 51:750-60
Manzanares, Dahis; Srinivasan, Maria; Salathe, Samuel T et al. (2014) IFN-?-mediated reduction of large-conductance, Ca2+-activated, voltage-dependent K+ (BK) channel activity in airway epithelial cells leads to mucociliary dysfunction. Am J Physiol Lung Cell Mol Physiol 306:L453-62
Conner, Gregory E; Ivonnet, Pedro; Gelin, Murline et al. (2013) H2O2 stimulates cystic fibrosis transmembrane conductance regulator through an autocrine prostaglandin pathway, using multidrug-resistant protein-4. Am J Respir Cell Mol Biol 49:672-9
Unwalla, Hoshang J; Horvath, Gabor; Roth, Felix D et al. (2012) Albuterol modulates its own transepithelial flux via changes in paracellular permeability. Am J Respir Cell Mol Biol 46:551-8

Showing the most recent 10 out of 21 publications