Abstract:
:G protein-coupled receptors mediate biological signals by stimulating nucleotide exchange in heterotrimeric G proteins (Galphabetagamma). Receptor dimers have been proposed as the functional unit responsible for catalytic interaction with Galphabetagamma. To investigate whether a G protein-coupled receptor monomer can activate Galphabetagamma, we used the retinal photoreceptor rhodopsin and its cognate G protein transducin (G(t)) to determine the stoichiometry of rhodopsin/G(t) binding and the rate of catalyzed nucleotide exchange in G(t). Purified rhodopsin was prepared in dodecyl maltoside detergent solution. Rhodopsin was monomeric as concluded from fluorescence resonance energy transfer, copurification studies with fluorescent labeled and unlabeled rhodopsin, size exclusion chromatography, and multiangle laser light scattering. A 1:1 complex between light-activated rhodopsin and G(t) was found in the elution profiles, and one molecule of GDP was released upon complex formation. Analysis of the speed of catalytic rhodopsin/G(t) interaction yielded a maximum of approximately 50 G(t) molecules per second and molecule of activated rhodopsin. The bimolecular rate constant is close to the diffusion limit in the diluted system. The results show that the interaction of G(t) with an activated rhodopsin monomer is sufficient for fully functional G(t) activation. Although the activation rate in solution is at the physically possible limit, the rate in the native membrane is still 10-fold higher. This is likely attributable to the precise orientation of the G protein to the membrane surface, which enables a fast docking process preceding the actual activation step. Whether docking in membranes involves the formation of rhodopsin dimers or oligomers remains to be elucidated.
journal_name
Proc Natl Acad Sci U S Aauthors
Ernst OP,Gramse V,Kolbe M,Hofmann KP,Heck Mdoi
10.1073/pnas.0701967104subject
Has Abstractpub_date
2007-06-26 00:00:00pages
10859-64issue
26eissn
0027-8424issn
1091-6490pii
0701967104journal_volume
104pub_type
杂志文章abstract::A 38-base-pair region required for normal CYC1 mRNA 3' end formation in Saccharomyces cerevisiae was shown to be necessary for the termination of transcription in vivo by examining the stability of CEN3 plasmids. CEN3 plasmids were stably maintained during vegetative growth, unless a GAL1 transcript impinged on the CE...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.86.21.8348
更新日期:1989-11-01 00:00:00
abstract::There is not a single pharmaceutical that halts or even slows any neurodegenerative disease. Mounting evidence shows that prions cause many neurodegenerative diseases, and arguably, scrapie and Creutzfeldt-Jakob disease prions represent the best therapeutic targets. We report here that the previously identified 2-amin...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1317164110
更新日期:2013-10-29 00:00:00
abstract::Type I (IFN-alpha/beta) and type III (IFN-lambdas) IFNs are important components of the host antiviral response. Although type III IFNs possess intrinsic antiviral activity similar to that of type I IFNs, they signal through a specific unique receptor complex, and their functional importance for antiviral resistance i...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0610352104
更新日期:2007-06-05 00:00:00
abstract::Ants are the world's most conspicuous and important eusocial insects and their diversity, abundance, and extreme behavioral specializations make them a model system for several disciplines within the biological sciences. Here, we report the discovery of a new ant that appears to represent the sister lineage to all ext...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0806187105
更新日期:2008-09-30 00:00:00
abstract::Cellular senescence is defined by the limited proliferative capacity of normal cultured cells. Immortal cells overcome this regulation and proliferate indefinitively. One step in the immortalization process may be reactivation of telomerase activity, a ribonucleoprotein complex, which, by de novo synthesized telomeric...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.93.13.6476
更新日期:1996-06-25 00:00:00
abstract::Earlier studies have shown that the DNA of herpes simplex virus 1 consists of two covalently linked components, L and S, each flanked by inverted repeats. The two components can invert, and viral DNA extracted from infected cells or virions consists of equimolar concentrations of four populations differing solely in t...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.80.9.2690
更新日期:1983-05-01 00:00:00
abstract::Social ties are crucial for physical and mental health. However, psychiatric patients frequently encounter social rejection. Moreover, an increased reactivity to social exclusion influences the development, progression, and treatment of various psychiatric disorders. Nevertheless, the neuromodulatory substrates of rej...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章,随机对照试验
doi:10.1073/pnas.1524187113
更新日期:2016-05-03 00:00:00
abstract::Quantitatively identifying direct dependencies between variables is an important task in data analysis, in particular for reconstructing various types of networks and causal relations in science and engineering. One of the most widely used criteria is partial correlation, but it can only measure linearly direct associ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1522586113
更新日期:2016-05-03 00:00:00
abstract::Osmotically shocked Escherichia coli and membrane vesicle ghosts from E. coli cells have lost the ability to accumulate potassium by active transport. The addition of valinomycin to the membrane ghosts restores the capacity to accumulate radioactive (42)K and (86)Rb by a temperature- and energy-dependent process. Memb...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.68.7.1488
更新日期:1971-07-01 00:00:00
abstract::Microorganisms must sense their environment and rapidly tune their metabolism to ambient conditions to efficiently use available resources. We have identified a gene encoding a response regulator, NblR, that complements a cyanobacterial mutant unable to degrade its light-harvesting complex (phycobilisome), in response...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.95.18.11008
更新日期:1998-09-01 00:00:00
abstract::Relaxin is a member of the insulin family of polypeptides that is best known as a reproductive hormone. In an effort to elucidate the mechanism of action of relaxin we previously localized the specific binding sites of a 32P-labeled relaxin in the rat uterus and brain. These studies suggested that, in addition to its ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.89.6.2384
更新日期:1992-03-15 00:00:00
abstract::Increased intestinal permeability has been observed in numerous human autoimmune diseases, including type-1 diabetes (T1D) and its' animal model, the BB-wor diabetic prone rat. We have recently described zonulin, a protein that regulates intercellular tight junctions. The objective of this study was to establish wheth...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0500178102
更新日期:2005-02-22 00:00:00
abstract::The science around the use of masks by the public to impede COVID-19 transmission is advancing rapidly. In this narrative review, we develop an analytical framework to examine mask usage, synthesizing the relevant literature to inform multiple areas: population impact, transmission characteristics, source control, wea...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章,评审
doi:10.1073/pnas.2014564118
更新日期:2021-01-26 00:00:00
abstract::The developmental origin of dendritic cells, a specialized system of major histocompatibility complex (MHC) class II-rich antigen-presenting cells for T-cell immunity and tolerance, is not well characterized. Granulocyte-macrophage colony-stimulating factor (GM-CSF) is known to stimulate dendritic cells, including gro...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.90.7.3038
更新日期:1993-04-01 00:00:00
abstract::The motor protein cytoplasmic dynein is responsible for most of the minus-end-directed microtubule traffic within cells. Dynein contains four evolutionarily conserved AAA (ATPase associated with various cellular activities) domains that are thought to bind nucleotide; the role of nucleotide binding and hydrolysis in e...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章,收录出版
doi:10.1073/pnas.2637011100
更新日期:2004-02-10 00:00:00
abstract::Two genes have a synthetically lethal relationship when the silencing or inhibiting of 1 gene is only lethal in the context of a mutation or activation of the second gene. This situation offers an attractive therapeutic strategy, as inhibition of such a gene will only trigger cell death in tumor cells with an activate...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0901418106
更新日期:2009-08-04 00:00:00
abstract::Gilles de la Tourette syndrome (TS) is characterized by tics, which are transiently worsened by stress, acute administration of dopaminergic drugs, and by subtle deficits in motor coordination and sensorimotor gating. It represents the most severe end of a spectrum of tic disorders that, in aggregate, affect ∼ 5% of t...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1419533112
更新日期:2015-01-20 00:00:00
abstract::Sr-bearing marine barite [(Ba x , Sr1-x )SO4] cycling has been widely used to reconstruct geochemical evolutions of paleoenvironments. However, an understanding of barite precipitation in the ocean, which is globally undersaturated with respect to barite, is missing. Moreo...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1821065116
更新日期:2019-07-02 00:00:00
abstract::Huntington's disease (HD) is a progressive neurodegenerative disorder caused by an expansion in the number of polyglutamine-encoding CAG repeats in the gene that encodes the huntingtin (htt) protein. A property of the mutant protein that is intimately involved in the development of the disease is the propensity of the...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0408134101
更新日期:2004-12-21 00:00:00
abstract::As a structure involved in learning and memory, the hippocampus functions as a network. The functional differentiation along the longitudinal axis of the hippocampus is poorly demarcated in comparison with the transverse axis. Using patch clamp recordings in conjunction with post hoc anatomy, we have examined the patt...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0506259102
更新日期:2005-09-13 00:00:00
abstract::The template-directed synthesis of a bistable donor-acceptor [2]catenane wherein both translational isomers--one in which a tetrathiafulvalene unit in a mechanically interlocked crown ether occupies the cavity of a cyclobis(paraquat-p-phenylene) ring and the other in which a 1,5-dioxynaphthalene unit in the crown ethe...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1009302107
更新日期:2010-08-10 00:00:00
abstract::P201 is a short (eight-residue) nonacidic peptide that comprises a strong transcriptional activating region when tethered to DNA in yeast. Here we identify the mediator protein Gal11 as an essential target of P201. Deletion of Gal11, which modestly decreases activation elicited by the typical acidic yeast activator, a...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.092263499
更新日期:2002-06-25 00:00:00
abstract::The redox siblings nitroxyl (HNO) and nitric oxide (NO) have often been assumed to undergo casual redox reactions in biological systems. However, several recent studies have demonstrated distinct pharmacological effects for donors of these two species. Here, infusion of the HNO donor Angeli's salt into normal dogs res...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1430507100
更新日期:2003-08-05 00:00:00
abstract::Any isospectral family of two-dimensional Euclidean domains is shown to be compact in the C(infinity) topology. Previously Melrose, using heat invariants, was able to establish the C(infinity) compactness of the curvature of the boundary curves. The additional ingredient used in this paper to obtain the compactness of...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.85.15.5359
更新日期:1988-08-01 00:00:00
abstract::Abnormal tubulofilamentous structures have been identified in electron micrographs of thin sections and negatively stained impression grids prepared from brains of animals with scrapie and other spongiform encephalopathies, and we showed that such tubules contain a core of filamentous structures resembling scrapie-ass...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.85.10.3575
更新日期:1988-05-01 00:00:00
abstract::R. A. Fisher's 1930 "reproductive value" is defined as the contribution made by a population's initial age elements to its asymptotically dominating exponential growth mode. For the Leslie discrete-time model, it is the characteristic row vector of the Leslie matrix, and for the integral-equation model of Lotka the si...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.74.11.5189
更新日期:1977-11-01 00:00:00
abstract::In many human cancers, tumor-specific chromosomal rearrangements are known to create chimeric products with the ability to transform cells. The EWS/WT1 protein is such a fusion product, resulting from a t(11;22) chromosomal translocation in desmoplastic small round cell tumors, where 265 aa from the EWS amino terminus...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.96.25.14300
更新日期:1999-12-07 00:00:00
abstract::Since their discovery as cell-division factors in plant tissue culture about five decades ago, cytokinins have been hypothesized to play a central role in the regulation of cell division and differentiation in plants. To test this hypothesis in planta, we isolated Arabidopsis plants lacking one, two, or three of the g...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0402887101
更新日期:2004-06-08 00:00:00
abstract::Bacterial transpeptidase and transglycosylase on the surface are essential for cell wall synthesis, and many antibiotics have been developed to target the transpeptidase; however, the problem of antibiotic resistance has arisen and caused a major threat in bacterial infection. The transglycosylase has been considered ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1203900109
更新日期:2012-04-24 00:00:00
abstract::Quantifying the uncertainty for the present climate and the predictions of climate change in the suite of imperfect Atmosphere Ocean Science (AOS) computer models is a central issue in climate change science. Here, a systematic approach to these issues with firm mathematical underpinning is developed through empirical...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1007009107
更新日期:2010-08-24 00:00:00