The long-term goal of this research program is to elucidate molecular mechanisms of function and regulation of the rod and cone cGMP-PDEs that serve as key effector enzymes in the visual transduction cascade of vertebrate photoreceptor cells. In the visual cascade, the GTP-bound form of G protein, transducin, activates PDE by relieving the inhibition imposed by the PDE-gamma subunits (PDE-gamma) on the enzyme catalytic subunits. Insights into the interaction between PDE-gamma and the catalytic subunits are critical for understanding the mechanisms of PDE activity inhibition by PDE-gamma and PDE activation by transducin. One of the objectives is to develop a detailed map of the PDE-gamma binding sites on PDE catalytic subunits using synthetic peptides as probes, and employing a crosslinking of specifically designed PDE-gamma mutants to the PDE catalytic subunits. In depth investigation of the photoreceptor PDE structure and function requires an extensive mutational analysis of the enzyme catalytic subunits. Mutagenesis of the PDE catalytic site, noncatalytic cGMP-binding sites and the PDE-gamma binding sites will be carried out. Specific amino-acid residues involved in the PDE functions will be identified. These studies will help to elucidate molecular details of cGMP hydrolysis by PDE, and of PDE activity inhibition by PDE-gamma. A better understanding of the role of noncatalytic cGMP-binding sites and their reciprocal relationships with the PDE-gamma binding sites is to be achieved. As a tool to develop an efficient expression system for mutagenesis of PDE, chimeric proteins with a maximal structural and functional resemblance to native PDEs will be made between photoreceptor PDEs and homologous cGMP-binding PDE. Transcriptional regulation of PDE genes is likely to participate in controlling proper stoichiometry and assembly of PDE subunits. The hypothesis that PDE-gamma may be involved in transcriptional regulation of the PDE catalytic subunit genes will be investigated. Clinical relevance of structure-function studies of PDE is underscored by the findings that link certain forms of human retinal degeneration to mutations of PDE catalytic subunits. These studies will aid in understanding the mechanisms of retinal degeneration caused by mutations of PDE genes.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY010843-07
Application #
6138195
Study Section
Visual Sciences C Study Section (VISC)
Program Officer
Mariani, Andrew P
Project Start
1995-01-01
Project End
2002-12-31
Budget Start
2000-01-01
Budget End
2000-12-31
Support Year
7
Fiscal Year
2000
Total Cost
$210,416
Indirect Cost
Name
University of Iowa
Department
Physiology
Type
Schools of Medicine
DUNS #
041294109
City
Iowa City
State
IA
Country
United States
Zip Code
52242
Yu, Liping; Yadav, Ravi P; Artemyev, Nikolai O (2018) NMR resonance assignments of the TPR domain of human aryl hydrocarbon receptor-interacting protein-like 1 (AIPL1). Biomol NMR Assign :
Wang, Tian; Reingruber, Jürgen; Woodruff, Michael L et al. (2018) The PDE6 mutation in the rd10 retinal degeneration mouse model causes protein mislocalization and instability and promotes cell death through increased ion influx. J Biol Chem 293:15332-15346
Pahlberg, Johan; Majumder, Anurima; Artemyev, Nikolai O (2018) Ex Vivo Functional Evaluation of Synaptic Transmission from Rods to Rod Bipolar Cells in Mice. Methods Mol Biol 1753:203-216
Yadav, Ravi P; Gakhar, Lokesh; Yu, Liping et al. (2017) Unique structural features of the AIPL1-FKBP domain that support prenyl lipid binding and underlie protein malfunction in blindness. Proc Natl Acad Sci U S A 114:E6536-E6545
Gopalakrishna, Kota N; Boyd, Kimberly; Artemyev, Nikolai O (2017) Mechanisms of mutant PDE6 proteins underlying retinal diseases. Cell Signal 37:74-80
Yadav, Ravi P; Artemyev, Nikolai O (2017) AIPL1: A specialized chaperone for the phototransduction effector. Cell Signal 40:183-189
Yu, Liping; Yadav, Ravi P; Artemyev, Nikolai O (2017) NMR resonance assignments of the FKBP domain of human aryl hydrocarbon receptor-interacting protein-like 1 (AIPL1) in complex with a farnesyl ligand. Biomol NMR Assign 11:111-115
Gopalakrishna, Kota N; Boyd, Kimberly; Yadav, Ravi P et al. (2016) Aryl Hydrocarbon Receptor-interacting Protein-like 1 Is an Obligate Chaperone of Phosphodiesterase 6 and Is Assisted by the ?-Subunit of Its Client. J Biol Chem 291:16282-91
Yadav, Ravi P; Majumder, Anurima; Gakhar, Lokesh et al. (2015) Extended conformation of the proline-rich domain of human aryl hydrocarbon receptor-interacting protein-like 1: implications for retina disease. J Neurochem 135:165-75
Majumder, Anurima; Pahlberg, Johan; Muradov, Hakim et al. (2015) Exchange of Cone for Rod Phosphodiesterase 6 Catalytic Subunits in Rod Photoreceptors Mimics in Part Features of Light Adaptation. J Neurosci 35:9225-35

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