Biomaterial Database

On the mechanism of the inhibition of transducin function by farnesylcysteine analogs. 1997

C A Parish, and D P Brazil, and R R Rando

Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, USA.

The gamma subunits of heterotrimeric G proteins are isoprenylated/methylated on their carboxy termini. The photoreceptor G protein, transducin, is farnesylated/methylated at this position. Since the isoprenyl group is required for G protein function, it is of great interest to determine the mechanism by which the farnesyl group of Tgamma interacts with the other transducin subunits and/or the activated photoreceptor, rhodopsin. Farnesylcysteine derivatives (N-acetyl-S-farnesyl-L-cysteine and farnesylated peptides) have been previously shown to have effects on transducin activity at high concentrations. Here, an extensive survey is done of farnesylcysteine analogs and other lipid molecules, which are tested for their ability to inhibit GTP/GDP exchange in transducin catalyzed by photolyzed rhodopsin. These studies are carried out to determine the nature of the inhibition process. While it does not appear that these molecules exhibit the specificity which would characterize a ligand-receptor type mechanism, the results suggest that these compounds are not acting in a nonspecific detergent-like manner either. The most likely mode of action of famesylcysteine analogs is that they interfere with the lipid-lipid based association of Talpha and Tbetagamma through the lipid modifications present on each subunit.

UI	MeSH Term	Description	Entries
D008969	Molecular Sequence Data	Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.	Sequence Data, Molecular,Molecular Sequencing Data,Data, Molecular Sequence,Data, Molecular Sequencing,Sequencing Data, Molecular
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
D003545	Cysteine	A thiol-containing non-essential amino acid that is oxidized to form CYSTINE.	Cysteine Hydrochloride,Half-Cystine,L-Cysteine,Zinc Cysteinate,Half Cystine,L Cysteine
D000111	Acetylcysteine	The N-acetyl derivative of CYSTEINE. It is used as a mucolytic agent to reduce the viscosity of mucous secretions. It has also been shown to have antiviral effects in patients with HIV due to inhibition of viral stimulation by reactive oxygen intermediates.	Mercapturic Acid,Acemuc,Acetabs,Acetylcystein AL,Acetylcystein Atid,Acetylcystein Heumann,Acetylcystein Trom,Acetylcysteine Hydrochloride,Acetylcysteine Sodium,Acetylcysteine Zinc,Acetylcysteine, (D)-Isomer,Acetylcysteine, (DL)-Isomer,Acetylcysteine, Monoammonium Salt,Acetylcysteine, Monosodium Salt,Acetylin,Acetyst,Acétylcystéine GNR,Airbron,Alveolex,Azubronchin,Bisolvon NAC,Bromuc,Broncho-Fips,Broncholysin,Broncoclar,Codotussyl,Cystamucil,Dampo Mucopect,Eurespiran,Exomuc,Fabrol,Fluimucil,Fluprowit,Frekatuss,Genac,Hoestil,Ilube,Jenacystein,Jenapharm,Lantamed,Larylin NAC,Lindocetyl,M-Pectil,Muciteran,Muco Sanigen,Mucomyst,Mucosil,Mucosol,Mucosolvin,N-Acetyl-L-cysteine,N-Acetylcysteine,NAC AL,NAC Zambon,Optipect Hustengetränk,Siccoral,Siran,Solmucol,acebraus,durabronchal,mentopin Acetylcystein,Acetylcystein, mentopin,Acid, Mercapturic,Broncho Fips,BronchoFips,Hustengetränk, Optipect,Hydrochloride, Acetylcysteine,M Pectil,MPectil,Monoammonium Salt Acetylcysteine,Monosodium Salt Acetylcysteine,Mucopect, Dampo,N Acetyl L cysteine,N Acetylcysteine,NAC, Bisolvon,Sanigen, Muco,Sodium, Acetylcysteine,Zambon, NAC,Zinc, Acetylcysteine
D000595	Amino Acid Sequence	The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.	Protein Structure, Primary,Amino Acid Sequences,Sequence, Amino Acid,Sequences, Amino Acid,Primary Protein Structure,Primary Protein Structures,Protein Structures, Primary,Structure, Primary Protein,Structures, Primary Protein
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
D013329	Structure-Activity Relationship	The relationship between the chemical structure of a compound and its biological or pharmacological activity. Compounds are often classed together because they have structural characteristics in common including shape, size, stereochemical arrangement, and distribution of functional groups.	Relationship, Structure-Activity,Relationships, Structure-Activity,Structure Activity Relationship,Structure-Activity Relationships
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
D019204	GTP-Binding Proteins	Regulatory proteins that act as molecular switches. They control a wide range of biological processes including: receptor signaling, intracellular signal transduction pathways, and protein synthesis. Their activity is regulated by factors that control their ability to bind to and hydrolyze GTP to GDP. EC 3.6.1.-.	G-Proteins,GTP-Regulatory Proteins,Guanine Nucleotide Regulatory Proteins,G-Protein,GTP-Binding Protein,GTP-Regulatory Protein,Guanine Nucleotide Coupling Protein,G Protein,G Proteins,GTP Binding Protein,GTP Binding Proteins,GTP Regulatory Protein,GTP Regulatory Proteins,Protein, GTP-Binding,Protein, GTP-Regulatory,Proteins, GTP-Binding,Proteins, GTP-Regulatory