Activated G-protein releases cGMP from high affinity binding sites on PDE from toad rod outer segments (ROS)
Abstract
cGMP binding proteins in toad ROS were identified by direct photoaffinity labeling (PAL) with /sup 32/P-cGMP and quantified by retention of complexes on nitrocellulose filters. By PAL, high affinity sites were present on the ..cap alpha.. and ..beta.. subunits of the cGMP-specific phosphodiesterase (PDE) which have MW/sub app/ of 94 and 90 kDa. A doublet was deduced from its photolabeling properties to represent PDE/sub ..gamma../ photocrosslinked with PDE/sub ..cap alpha../ or PDE/sub ..beta../, respectively. cGMP prebound to these high affinity sites was released by light-activated G-protein or its ..cap alpha.. subunit complexed with GTP..gamma..S; this inhibition of cGMP binding to PDE did not result from decreased cGMP availability due to enhanced hydrolysis. A low affinity cGMP binding component identified by PAL is tightly associated with ROS membranes. Apparent ATP/light-dependent stimulation of cGMP binding was shown to result from light activated cGMP hydrolysis in conjunction with ATP-promoted conversion of GMP to GDP/GTP and increased GDP/GTP binding. These findings coincide with a model for light-related regulation of cGMP binding and metabolism predicted from intact and cellfree kinetic measurements: in the dark state the cGMP hydrolic rate is constrained by the availability of cGMP because of its binding to high affinity sites onmore »
- Authors:
- Publication Date:
- Research Org.:
- Univ. of Minnesota, Minneapolis
- OSTI Identifier:
- 6180050
- Report Number(s):
- CONF-870644-
Journal ID: CODEN: FEPRA; TRN: 87-033995
- Resource Type:
- Conference
- Journal Name:
- Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)
- Additional Journal Information:
- Journal Volume: 46:6; Conference: 78. annual meeting of the American Society of Biological Chemists conference, Philadelphia, PA, USA, 7 Jun 1987
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 59 BASIC BIOLOGICAL SCIENCES; NUCLEOTIDES; BIOCHEMICAL REACTION KINETICS; RECEPTORS; PHOSPHODIESTERASES; CROSS-LINKING; PROTEINS; BIOLOGICAL FUNCTIONS; LABELLING; AFFINITY; CELL MEMBRANES; EYES; FROGS; PHOSPHORUS 32; TRACER TECHNIQUES; AMPHIBIANS; ANIMALS; AQUATIC ORGANISMS; BETA DECAY RADIOISOTOPES; BETA-MINUS DECAY RADIOISOTOPES; BODY; BODY AREAS; CELL CONSTITUENTS; CHEMICAL REACTIONS; DAYS LIVING RADIOISOTOPES; ENZYMES; ESTERASES; FACE; FUNCTIONS; HEAD; HYDROLASES; ISOTOPE APPLICATIONS; ISOTOPES; KINETICS; LIGHT NUCLEI; MEMBRANE PROTEINS; MEMBRANES; NUCLEI; ODD-ODD NUCLEI; ORGANIC COMPOUNDS; ORGANS; PHOSPHORUS ISOTOPES; POLYMERIZATION; RADIOISOTOPES; REACTION KINETICS; SENSE ORGANS; VERTEBRATES; 550201* - Biochemistry- Tracer Techniques
Citation Formats
Yuen, P S.T., Walseth, T F, Panter, S S, Sundby, S R, Graeff, R M, and Goldberg, N D. Activated G-protein releases cGMP from high affinity binding sites on PDE from toad rod outer segments (ROS). United States: N. p., 1987.
Web.
Yuen, P S.T., Walseth, T F, Panter, S S, Sundby, S R, Graeff, R M, & Goldberg, N D. Activated G-protein releases cGMP from high affinity binding sites on PDE from toad rod outer segments (ROS). United States.
Yuen, P S.T., Walseth, T F, Panter, S S, Sundby, S R, Graeff, R M, and Goldberg, N D. 1987.
"Activated G-protein releases cGMP from high affinity binding sites on PDE from toad rod outer segments (ROS)". United States.
@article{osti_6180050,
title = {Activated G-protein releases cGMP from high affinity binding sites on PDE from toad rod outer segments (ROS)},
author = {Yuen, P S.T. and Walseth, T F and Panter, S S and Sundby, S R and Graeff, R M and Goldberg, N D},
abstractNote = {cGMP binding proteins in toad ROS were identified by direct photoaffinity labeling (PAL) with /sup 32/P-cGMP and quantified by retention of complexes on nitrocellulose filters. By PAL, high affinity sites were present on the ..cap alpha.. and ..beta.. subunits of the cGMP-specific phosphodiesterase (PDE) which have MW/sub app/ of 94 and 90 kDa. A doublet was deduced from its photolabeling properties to represent PDE/sub ..gamma../ photocrosslinked with PDE/sub ..cap alpha../ or PDE/sub ..beta../, respectively. cGMP prebound to these high affinity sites was released by light-activated G-protein or its ..cap alpha.. subunit complexed with GTP..gamma..S; this inhibition of cGMP binding to PDE did not result from decreased cGMP availability due to enhanced hydrolysis. A low affinity cGMP binding component identified by PAL is tightly associated with ROS membranes. Apparent ATP/light-dependent stimulation of cGMP binding was shown to result from light activated cGMP hydrolysis in conjunction with ATP-promoted conversion of GMP to GDP/GTP and increased GDP/GTP binding. These findings coincide with a model for light-related regulation of cGMP binding and metabolism predicted from intact and cellfree kinetic measurements: in the dark state the cGMP hydrolic rate is constrained by the availability of cGMP because of its binding to high affinity sites on PDE. Light activated G-protein releases cGMP from these sites and allows for its redistribution to lower affinity sites represented by PDE catalytic site(s) and possible cGMP-dependent membrane cation channels.},
doi = {},
url = {https://www.osti.gov/biblio/6180050},
journal = {Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)},
number = ,
volume = 46:6,
place = {United States},
year = {Fri May 01 00:00:00 EDT 1987},
month = {Fri May 01 00:00:00 EDT 1987}
}