The central focus of the renewal will be on understanding how CFTR interacts with other proteins. The concept of how transport proteins work together to coordinate the transport of solutes and water across epithelial cell membranes has been a question fundamental to epithelial physiology. A combination of molecular and physiological experiments will give us the opportunity to address long standing questions regarding transporter homeostasis To address this issue we will focus on proteins that bind to CFTR and enable it to function in a macro-molecular complex. During the previous budget period we have discovered a new protein called CAL (CFFR associated ligand). CAL is a new member of the PDZ domain protein family. in addition to a single PDZ domain, CAL is predicted to have other protein interacting regions (coiled-coil domains). CAL binding to the cytoplasmic carboxy-terminus of CFTR via its PDZ domain organizes CFTR into protein clusters. Apical localization indicates that CAL serves as a scaffold protein that interacts with CFTR at the epithelial plasma membrane. CFTR, an epithelial Cl- channel defective in cystic fibrosis (CF), has been functionally linked to other proteins. The Project has three goals to determine the functional consequences of the interaction between CAL and CFTR, to identify the structural domains of CFTR critical for the regulatory interaction between CFTR and CAL and to determine what are the functional consequences of multiple PDZ domain proteins that bind to CFTR. These studies will employ a combination of approaches. The ultimate goal of these studies is to provide novel insights into how CFTR functions in a macromolecular complex. The reasons for gaining more information on the terminal amino acids of CFTR and proteins such as CAL that bind to it are at least two-fold. First, CFTR is a transport protein that functions in a variety of epithelial cells. More importantly, information how CFTR interacts with other proteins will increase our information on how mutant CFTR causes CF. This is particularly important to our understanding of lung pathobiology whose severity of disease often does not correlate with genotype. Finally, the novel proteins that bind to CFTR provide important targets for pharmacologic therapies.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL047122-11
Application #
6363517
Study Section
Special Emphasis Panel (ZRG1-SSS-G (03))
Program Officer
Banks-Schlegel, Susan P
Project Start
1991-04-01
Project End
2005-02-28
Budget Start
2001-03-01
Budget End
2002-02-28
Support Year
11
Fiscal Year
2001
Total Cost
$423,758
Indirect Cost
Name
Johns Hopkins University
Department
Physiology
Type
Schools of Medicine
DUNS #
045911138
City
Baltimore
State
MD
Country
United States
Zip Code
21218
Tukaye, Deepali N; Kwon, Sang-Ho; Guggino, Wiliam B (2013) The GAP portion of Pseudomonas aeruginosa type III secreted toxin ExoS upregulates total and surface levels of wild type CFTR. Cell Physiol Biochem 31:153-65
Cheng, Jie; Cebotaru, Valeriu; Cebotaru, Liudmila et al. (2010) Syntaxin 6 and CAL mediate the degradation of the cystic fibrosis transmembrane conductance regulator. Mol Biol Cell 21:1178-87
Krasnov, Kristina V; Tzetis, Maria; Cheng, Jie et al. (2008) Localization studies of rare missense mutations in cystic fibrosis transmembrane conductance regulator (CFTR) facilitate interpretation of genotype-phenotype relationships. Hum Mutat 29:1364-72
Kwon, Sang-Ho; Pollard, Harvey; Guggino, William B (2007) Knockdown of NHERF1 enhances degradation of temperature rescued DeltaF508 CFTR from the cell surface of human airway cells. Cell Physiol Biochem 20:763-72
Wolde, Michael; Fellows, Abigail; Cheng, Jie et al. (2007) Targeting CAL as a negative regulator of DeltaF508-CFTR cell-surface expression: an RNA interference and structure-based mutagenetic approach. J Biol Chem 282:8099-109
Rebelo, Maria Alice P; Tostes, Vera; Araujo, Nordeval C et al. (2005) Screening for CLCN5 mutation in renal calcium stone formers patients. An Acad Bras Cienc 77:95-101
Cheng, Jie; Wang, Hua; Guggino, William B (2005) Regulation of cystic fibrosis transmembrane regulator trafficking and protein expression by a Rho family small GTPase TC10. J Biol Chem 280:3731-9
Guggino, William B (2004) The cystic fibrosis transmembrane regulator forms macromolecular complexes with PDZ domain scaffold proteins. Proc Am Thorac Soc 1:28-32
Hryciw, Deanne H; Ekberg, Jenny; Lee, Aven et al. (2004) Nedd4-2 functionally interacts with ClC-5: involvement in constitutive albumin endocytosis in proximal tubule cells. J Biol Chem 279:54996-5007
Cheng, Jie; Wang, Hua; Guggino, William B (2004) Modulation of mature cystic fibrosis transmembrane regulator protein by the PDZ domain protein CAL. J Biol Chem 279:1892-8

Showing the most recent 10 out of 53 publications