Regulation of retinal cgmp phosphodiesterases

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Project Title: Regulation of retinal cgmp phosphodiesterases
Principal Investigators (PI): ARTEMYEV NIKOLAI O
Project Number: 2R01EY010843-10
Organization: UNIVERSITY OF IOWA
 
Project Description:
The long-term goal of this research program as to elucidate molecular mechanisms of function and regulation of rod and cone cGMP-phosphodiesterases (PDE6) Rod and cone PDE6 serve as key effector enzymes in the vertebrate visual transduction cascade. Transducin activates PDE6 by relieving the inhibition imposed on the PDE6 catalytic dimer by two gamma-subunits (Pgamma). Activated PDE6 hydrolyzes cGMP with a uniquely high catalytic rate. To study the structure-and-function relationships of PDE6 we have developed a system for expression of PDE6alpha/PDE5 chimeras in insect cells. A chimeric PDE6/PDE5 enzyme maximally equivalent to PDE6 will be generated through a progressive incorporation of PDE6 sequence into existing functional PDE6/PDE5 chimeras. Mutational analysis of the PDE6-like chimeric enzymes guided by the model of PDE6 catalytic domain will be carried out to identify the structural elements of PDE6 critical for the efficient hydrolysis of cGMP and the enzyme sensitivity to selective competitive inhibitors. PDE6 catalytic subunits contain two N-terminal GAF domains, GAFa and GAFb, implicated in noncatalytic binding of cGMP. We have found that the polycationic region of Pgamma binds to the GAFa domains of PDE6. We hypothesize that a direct stabilization of the cGMP-binding pocket by Pgamma is the mechanism for known positive cooperativity between Pgamma and noncatalytic cGMP binding. To test this hypothesis. Pgamma contact residues within the GAFa domain of PDE6 will be identified by mutagenesis. The GAF domains and residues involved in the noncatalytic cGMP-binding will be identified by substituting selected residues within potential cGMP-pockets of PDE6. Models of PDE6 GAF domains will be utilized to elucidate the nature of the reciprocal relationship between the cGMP and Pgamma-binding sites. Rod PDE6 catalytic alpha and beta subunits form indissociable alphabeta heterodimers, whereas cone PDE6 alpha' subunit forms alpha' alpha' homodimers. Although the GAF domains of PDE6 are thought to be involved in the dimerization, the PDE6 intersubunit interface has not been investigated. Sites and residues responsible for the specific dimerization of PDE6 will be identified through the analysis of dimer formation between chimeric and mutant PDEs. The role of specific PDE6 residues will be established by inducing homodimerization between mutant GAF domains of PDE6 alpha and beta. The map of PDEalpha/beta-Pgamma interactions indicates two possible types of assembly of PDE6. A Pgamma molecule may bind to GAFa and the catalytic site from the same or different subunits of the catalytic dimer. The assembly of PDE6 subunits will be tested using a cross-linking approach. These studies will advance our understanding of the structure, function, and regulation of PDE6, and help to elucidate the mechanisms of retinal degeneration caused by mutations of PDE6 genes.
 
Project Terms:
visual phototransduction enzyme activity transducin phosphodiesterases rod cell cone cell cyclic GMP protein binding synthetic peptide genetic regulation molecular site hydrolysis gene mutation protein structure function chimeric proteins yeast two hybrid system fluorescent dye /probe site directed mutagenesis protein sequence animal tissue
Project Title: Regulation of retinal cgmp phosphodiesterases
Principal Investigators (PI): ARTEMYEV NIKOLAI O
Project Number: 2R01EY010843-10
Organization: UNIVERSITY OF IOWA
 
Project Categories:
• Natural Sciences > Aging Diseases and Pathology > Neurodegenerative diseases > Amyotrophic lateral sclerosis
 
Other Information:
Fiscal Year: 1995
Project Start Date: 1 January 1994
Project End Date: 31 December 2008
Administering Institute Or Center: EY
 
Project Funding Information:
Total Funding: $331,313
Year Funding Organization Total Funding, $
2003 NATIONAL EYE INSTITUTE $331,313
Project Title: Regulation of retinal cgmp phosphodiesterases
Principal Investigators (PI): ARTEMYEV NIKOLAI O
Project Number: 2R01EY010843-10
Organization: UNIVERSITY OF IOWA
 
Project_number Title Year FY Total Cost
There are no results for this project in database.
Project Title: Regulation of retinal cgmp phosphodiesterases
Principal Investigators (PI): ARTEMYEV NIKOLAI O
Project Number: 2R01EY010843-10
Organization: UNIVERSITY OF IOWA
 
Project number Project title Organization FY Funding Organization FY Total Cost
2R01EY012682-05Molecular Mechanism of Photoreceptor G Protein SignalingUNIVERSITY OF IOWA2004NATIONAL EYE INSTITUTE
$368,750
5R01EY010843-11Regulation of Retinal cGMP PhosphodiesterasesUNIVERSITY OF IOWA2004NATIONAL EYE INSTITUTE
$331,875
5R01EY012682-04MOLECULAR MECHANISM OF PHOTORECEPTOR G PROTEIN SIGNALINGUNIVERSITY OF IOWA2003NATIONAL EYE INSTITUTE
$220,500
2R01EY010843-10Regulation of Retinal cGMP PhosphodiesterasesUNIVERSITY OF IOWA2003NATIONAL EYE INSTITUTE
$331,313
5R01EY012682-03MOLECULAR MECHANISM OF PHOTORECEPTOR G PROTEIN SIGNALINGUNIVERSITY OF IOWA2002NATIONAL EYE INSTITUTE
$220,500
5R01EY010843-09REGULATION OF RETINAL CYCLIC GMP PHOSPHODIESTERASESUNIVERSITY OF IOWA2002NATIONAL EYE INSTITUTE
$223,231
5R01EY012682-02MOLECULAR MECHANISM OF PHOTORECEPTOR G PROTEIN SIGNALINGUNIVERSITY OF IOWA2001NATIONAL EYE INSTITUTE
$220,500
5R01EY010843-08REGULATION OF RETINAL CYCLIC GMP PHOSPHODIESTERASESUNIVERSITY OF IOWA2001NATIONAL EYE INSTITUTE
$216,729
1R01EY012682-01A1MOLECULAR MECHANISM OF PHOTORECEPTOR G PROTEIN SIGNALINGUNIVERSITY OF IOWA2000NATIONAL EYE INSTITUTE
$217,351
5R01EY010843-07REGULATION OF RETINAL CYCLIC GMP PHOSPHODIESTERASESUNIVERSITY OF IOWA2000NATIONAL EYE INSTITUTE
$210,416
5R01EY010843-12Regulation of Retinal cGMP PhosphodiesterasesUNIVERSITY OF IOWA2005NATIONAL EYE INSTITUTE
$331,875
5R01EY012682-06Molecular Mechanism of Photoreceptor G Protein SignalingUNIVERSITY OF IOWA2005NATIONAL EYE INSTITUTE
$368,750
5R01EY010843-13Regulation of Retinal cGMP PhosphodiesterasesUNIVERSITY OF IOWA2006NATIONAL EYE INSTITUTE
$324,077
5R01EY012682-07Molecular Mechanism of Photoreceptor G Protein SignalingUNIVERSITY OF IOWA2006NATIONAL EYE INSTITUTE
$360,084
5R01EY010843-14Regulation of Retinal cGMP PhosphodiesterasesUNIVERSITY OF IOWA2007NATIONAL EYE INSTITUTE
$322,262
5R01EY012682-08Molecular Mechanism of Photoreceptor G Protein SignalingUNIVERSITY OF IOWA2007NATIONAL EYE INSTITUTE
$358,068
2R01EY010843-15A1Regulation of Retinal cGMP phosphodiesterasesUNIVERSITY OF IOWA2008NATIONAL EYE INSTITUTE
$371,090
5R01EY012682-09Molecular Mechanism of Photoreceptor G Protein SignalingUNIVERSITY OF IOWA2008NATIONAL EYE INSTITUTE
$350,907
5R01EY010843-16Regulation of Retinal cGMP phosphodiesterasesUNIVERSITY OF IOWA2009NATIONAL EYE INSTITUTE
$370,972
3R01EY010843-16S1Regulation of Retinal cGMP phosphodiesterasesUNIVERSITY OF IOWA2009NATIONAL EYE INSTITUTE
$54,082
Project Title: Regulation of retinal cgmp phosphodiesterases
Principal Investigators (PI): ARTEMYEV NIKOLAI O
Project Number: 2R01EY010843-10
Organization: UNIVERSITY OF IOWA
 
Project number Project title Principal investigator
There are no any related projects.
Project Title: Regulation of retinal cgmp phosphodiesterases
Principal Investigators (PI): ARTEMYEV NIKOLAI O
Project Number: 2R01EY010843-10
Organization: UNIVERSITY OF IOWA
 
Title Abstract Authors Year Rel
Mutation in rod PDE6 linked to congenital stationary night blindness impairs the enzyme inhibition by its gamma-subunit. Biochemistry.. 2003 Mar 25 42 (11) :3305-10 Muradov, Khakim G; Granovsky, Alexey E; Artemyev, Nikolai O 2003
The GAFa domains of rod cGMP-phosphodiesterase 6 determine the selectivity of the enzyme dimerization. The Journal of biological chemistry.. 2003 Mar 21 278 (12) :10594-601 Muradov, Khakim G; Boyd, Kimberly K; Martinez, Sergio E; Beavo, Joseph A; Artemyev, Nikolai O 2003