Direct interaction of the inhibitory gamma-subunit of Rod cGMP phosphodiesterase (PDE6) with the PDE6 GAFa domains

Khakim G Muradov; Alexey E Granovsky; Kevin L Schey; Nikolai O Artemyev

doi:10.1021/bi015935m

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Direct interaction of the inhibitory gamma-subunit of Rod cGMP phosphodiesterase (PDE6) with the PDE6 GAFa domains

Journal article

Peer reviewed

Direct interaction of the inhibitory gamma-subunit of Rod cGMP phosphodiesterase (PDE6) with the PDE6 GAFa domains

Khakim G Muradov, Alexey E Granovsky, Kevin L Schey and Nikolai O Artemyev

Biochemistry (Easton), Vol.41(12), pp.3884-3890

03/26/2002

DOI: 10.1021/bi015935m

PMID: 11900530

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Abstract

Retinal rod and cone cGMP phosphodiesterases (PDE6 family) function as the effector enzyme in the vertebrate visual transduction cascade. The activity of PDE6 catalytic subunits is controlled by the Pgamma-subunits. In addition to the inhibition of cGMP hydrolysis at the catalytic sites, Pgamma is known to stimulate a noncatalytic binding of cGMP to the regulatory GAFa-GAFb domains of PDE6. The latter role of Pgamma has been attributed to its polycationic region. To elucidate the structural basis for the regulation of cGMP binding to the GAF domains of PDE6, a photoexcitable peptide probe corresponding to the polycationic region of Pgamma, Pgamma-21-45, was specifically cross-linked to rod PDE6alphabeta. The site of Pgamma-21-45 cross-linking was localized to Met138Gly139 within the PDE6alpha GAFa domain using mass spectrometric analysis. Chimeras between PDE5 and cone PDE6alpha', containing GAFa and/or GAFb domains of PDE6alpha' have been generated to probe a potential role of the GAFb domains in binding to Pgamma. Analysis of the inhibition of the PDE5/PDE6alpha' chimeras by Pgamma supported the role of PDE6 GAFa but not GAFb domains in the interaction with Pgamma. Our results suggest that a direct binding of the polycationic region of Pgamma to the GAFa domains of PDE6 may lead to a stabilization of the noncatalytic cGMP-binding sites.

Amino Acid Sequence

Catalytic Domain

Phosphoric Diester Hydrolases - metabolism

Models, Molecular

Molecular Sequence Data

Phosphoric Diester Hydrolases - genetics

Phosphoric Diester Hydrolases - chemistry

Sequence Homology, Amino Acid

Animals

Cattle

Mass Spectrometry

Cloning, Molecular

Retinal Rod Photoreceptor Cells - enzymology

Cyclic Nucleotide Phosphodiesterases, Type 6

Details

Title: Subtitle: Direct interaction of the inhibitory gamma-subunit of Rod cGMP phosphodiesterase (PDE6) with the PDE6 GAFa domains
Creators: Khakim G Muradov - Department of Physiology and Biophysics, University of Iowa College of Medicine, Iowa City, Iowa 52242, USA
Alexey E Granovsky
Kevin L Schey
Nikolai O Artemyev
Resource Type: Journal article
Publication Details: Biochemistry (Easton), Vol.41(12), pp.3884-3890
Publisher: United States
DOI: 10.1021/bi015935m
PMID: 11900530
ISSN: 0006-2960
eISSN: 1520-4995
Grant note: DK-25295 / NIDDK NIH HHS EY-10843 / NEI NIH HHS
Language: English
Date published: 03/26/2002
Academic Unit: Molecular Physiology and Biophysics; Iowa Neuroscience Institute; Ophthalmology and Visual Sciences
Record Identifier: 9984025452802771

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