Transducin subunit stoichiometry and cellular distribution in rod outer segments. 2006

James W Clack, and Matthew L Springmeyer, and Candice R Clark, and Frank A Witzmann
Department of Biology, Indiana University, Purdue University at Indianapolis, 4601 Central Ave., Columbus, IN 47203, USA. jclack@iupui.edu

Transducin is a heterotrimeric GTP-binding protein found in the outer segment of vertebrate retinas that links the photoactivation of rhodopsin (R*) with activation of a robust type VI cGMP phosphodiesterase (PDE6). Association of the alpha subunit of Transducin (G(alphat)) with the beta-gamma complex (G(betagamma)) is necessary for interaction of the holoprotein with R* and exchange of a GTP for a previously bound GDP. We have investigated the abundances of the three Transducin subunits by eluting them from bovine rod outer segment membranes by centrifugation under various conditions in vitro. We find that a substantial amount of G(betagamma) is eluted from ROS under conditions that do not elute G(alphat) and that there is an overall three to fourfold molar excess of G(betagamma) to G(alphat) in rod outer segments. These results suggest that the production and/or turnover of G(alphat), G(beta), and G(gamma) in the rod outer segment are controlled independently.

UI MeSH Term Description Entries
D002417 Cattle Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor. Beef Cow,Bos grunniens,Bos indicus,Bos indicus Cattle,Bos taurus,Cow,Cow, Domestic,Dairy Cow,Holstein Cow,Indicine Cattle,Taurine Cattle,Taurus Cattle,Yak,Zebu,Beef Cows,Bos indicus Cattles,Cattle, Bos indicus,Cattle, Indicine,Cattle, Taurine,Cattle, Taurus,Cattles, Bos indicus,Cattles, Indicine,Cattles, Taurine,Cattles, Taurus,Cow, Beef,Cow, Dairy,Cow, Holstein,Cows,Dairy Cows,Domestic Cow,Domestic Cows,Indicine Cattles,Taurine Cattles,Taurus Cattles,Yaks,Zebus
D004591 Electrophoresis, Polyacrylamide Gel Electrophoresis in which a polyacrylamide gel is used as the diffusion medium. Polyacrylamide Gel Electrophoresis,SDS-PAGE,Sodium Dodecyl Sulfate-PAGE,Gel Electrophoresis, Polyacrylamide,SDS PAGE,Sodium Dodecyl Sulfate PAGE,Sodium Dodecyl Sulfate-PAGEs
D004797 Enzyme-Linked Immunosorbent Assay An immunoassay utilizing an antibody labeled with an enzyme marker such as horseradish peroxidase. While either the enzyme or the antibody is bound to an immunosorbent substrate, they both retain their biologic activity; the change in enzyme activity as a result of the enzyme-antibody-antigen reaction is proportional to the concentration of the antigen and can be measured spectrophotometrically or with the naked eye. Many variations of the method have been developed. ELISA,Assay, Enzyme-Linked Immunosorbent,Assays, Enzyme-Linked Immunosorbent,Enzyme Linked Immunosorbent Assay,Enzyme-Linked Immunosorbent Assays,Immunosorbent Assay, Enzyme-Linked,Immunosorbent Assays, Enzyme-Linked
D000818 Animals Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA. Animal,Metazoa,Animalia
D012374 Rod Cell Outer Segment The portion of a retinal rod cell situated between the ROD INNER SEGMENT and the RETINAL PIGMENT EPITHELIUM. It contains a stack of photosensitive disk membranes laden with RHODOPSIN. Rod Outer Segment,Rod Outer Segments,Outer Segment, Rod,Outer Segments, Rod
D014018 Tissue Distribution Accumulation of a drug or chemical substance in various organs (including those not relevant to its pharmacologic or therapeutic action). This distribution depends on the blood flow or perfusion rate of the organ, the ability of the drug to penetrate organ membranes, tissue specificity, protein binding. The distribution is usually expressed as tissue to plasma ratios. Distribution, Tissue,Distributions, Tissue,Tissue Distributions
D015151 Immunoblotting Immunologic method used for detecting or quantifying immunoreactive substances. The substance is identified by first immobilizing it by blotting onto a membrane and then tagging it with labeled antibodies. Dot Immunoblotting,Electroimmunoblotting,Immunoelectroblotting,Reverse Immunoblotting,Immunoblotting, Dot,Immunoblotting, Reverse,Dot Immunoblottings,Electroimmunoblottings,Immunoblottings,Immunoblottings, Dot,Immunoblottings, Reverse,Immunoelectroblottings,Reverse Immunoblottings
D015293 Transducin A heterotrimeric GTP-binding protein that mediates the light activation signal from photolyzed rhodopsin to cyclic GMP phosphodiesterase and is pivotal in the visual excitation process. Activation of rhodopsin on the outer membrane of rod and cone cells causes GTP to bind to transducin followed by dissociation of the alpha subunit-GTP complex from the beta/gamma subunits of transducin. The alpha subunit-GTP complex activates the cyclic GMP phosphodiesterase which catalyzes the hydrolysis of cyclic GMP to 5'-GMP. This leads to closure of the sodium and calcium channels and therefore hyperpolarization of the rod cells. G-Protein, Inhibitory Gt,Gt, Transducin G-Protein,alpha-Transducin,beta-Transducin,gamma-Transducin,Transducin G-Protein (Gt),Transducin, alpha Subunit,Transducin, beta Subunit,Transducin, gamma Subunit,G Protein, Inhibitory Gt,G-Protein Gt, Transducin,Gt G-Protein, Inhibitory,Gt, Transducin G Protein,Inhibitory Gt G-Protein,Transducin G-Protein Gt,alpha Subunit Transducin,alpha Transducin,beta Subunit Transducin,beta Transducin,gamma Subunit Transducin,gamma Transducin
D021122 Protein Subunits Single chains of amino acids that are the units of multimeric PROTEINS. Multimeric proteins can be composed of identical or non-identical subunits. One or more monomeric subunits may compose a protomer which itself is a subunit structure of a larger assembly. Protomers,Protein Subunit,Protomer,Subunit, Protein,Subunits, Protein

Related Publications

James W Clack, and Matthew L Springmeyer, and Candice R Clark, and Frank A Witzmann
August 1988, Science (New York, N.Y.),
James W Clack, and Matthew L Springmeyer, and Candice R Clark, and Frank A Witzmann
March 2003, Biochemical and biophysical research communications,
James W Clack, and Matthew L Springmeyer, and Candice R Clark, and Frank A Witzmann
August 1994, The Journal of biological chemistry,
James W Clack, and Matthew L Springmeyer, and Candice R Clark, and Frank A Witzmann
January 2010, Biofizika,
James W Clack, and Matthew L Springmeyer, and Candice R Clark, and Frank A Witzmann
August 1988, Science (New York, N.Y.),
James W Clack, and Matthew L Springmeyer, and Candice R Clark, and Frank A Witzmann
January 1983, Methods in enzymology,
James W Clack, and Matthew L Springmeyer, and Candice R Clark, and Frank A Witzmann
November 2000, Journal of neurochemistry,
James W Clack, and Matthew L Springmeyer, and Candice R Clark, and Frank A Witzmann
January 1995, Biological research,
James W Clack, and Matthew L Springmeyer, and Candice R Clark, and Frank A Witzmann
April 1989, FEBS letters,
James W Clack, and Matthew L Springmeyer, and Candice R Clark, and Frank A Witzmann
July 1993, Doklady Akademii nauk,
Copied contents to your clipboard!