986 resultados para Bacteriophage lambda tail
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This document lists trophy white-tail deer. A deer qualifies as a trophy by the score of the conformation of its antlers and and by type of weapon that was used.
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Let $ E_{\lambda}(z)=\lambda {\rm exp}(z), \lambda\in \mathbb{C}$, be the complex exponential family. For all functions in the family there is a unique asymptotic value at 0 (and no critical values). For a fixed $ \lambda$, the set of points in $ \mathbb{C}$ with orbit tending to infinity is called the escaping set. We prove that the escaping set of $ E_{\lambda}$ with $ \lambda$ Misiurewicz (that is, a parameter for which the orbit of the singular value is strictly preperiodic) is a connected set.
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Hepatitis C virus (HCV) nonstructural protein 5B (NS5B), the viral RNA-dependent RNA polymerase (RdRp), is a tail-anchored protein with a highly conserved C-terminal transmembrane domain (TMD) that is required for the assembly of a functional replication complex. Here, we report that the TMD of the HCV RdRp can be functionally replaced by a newly identified analogous membrane anchor of the GB virus B (GBV-B) NS5B RdRp. Replicons with a chimeric RdRp consisting of the HCV catalytic domain and the GBV-B membrane anchor replicated with reduced efficiency. Compensatory amino acid changes at defined positions within the TMD improved the replication efficiency of these chimeras. These observations highlight a conserved structural motif within the TMD of the HCV NS5B RdRp that is required for RNA replication.
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Standard practice of wave-height hazard analysis often pays little attention to the uncertainty of assessed return periods and occurrence probabilities. This fact favors the opinion that, when large events happen, the hazard assessment should change accordingly. However, uncertainty of the hazard estimates is normally able to hide the effect of those large events. This is illustrated using data from the Mediterranean coast of Spain, where the last years have been extremely disastrous. Thus, it is possible to compare the hazard assessment based on data previous to those years with the analysis including them. With our approach, no significant change is detected when the statistical uncertainty is taken into account. The hazard analysis is carried out with a standard model. Time-occurrence of events is assumed Poisson distributed. The wave-height of each event is modelled as a random variable which upper tail follows a Generalized Pareto Distribution (GPD). Moreover, wave-heights are assumed independent from event to event and also independent of their occurrence in time. A threshold for excesses is assessed empirically. The other three parameters (Poisson rate, shape and scale parameters of GPD) are jointly estimated using Bayes' theorem. Prior distribution accounts for physical features of ocean waves in the Mediterranean sea and experience with these phenomena. Posterior distribution of the parameters allows to obtain posterior distributions of other derived parameters like occurrence probabilities and return periods. Predictives are also available. Computations are carried out using the program BGPE v2.0
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Résumé Métropolisation, morphologie urbaine et développement durable. Transformations urbaines et régulation de l'étalement : le cas de l'agglomération lausannoise. Cette thèse s'inscrit clans la perspective d'une analyse stratégique visant à un définir et à expliciter les liens entre connaissance, expertise et décision politique. L'hypothèse fondamentale qui oriente l'ensemble de ce travail est la suivante : le régime d'urbanisation qui s'est imposé au cours des trente dernières années correspond à une transformation du principe morphogénétique de développement spatial des agglomérations qui tend à alourdir leurs bilans écologiques et à péjorer la qualité du cadre de vie des citadins. Ces enjeux environnementaux liés aux changements urbains et singulièrement ceux de la forme urbaine constituent un thème de plus en plus important dans la recherche de solutions d'aménagement urbain dans une perspective de développement durable. Dans ce contexte, l'aménagement urbain devient un mode d'action et une composante de tout premier ordre des politiques publiques visant un développement durable à l'échelle locale et globale. Ces modalités de développement spatial des agglomérations émergent indiscutablement au coeur de la problématique environnementale. Or si le concept de développement durable nous livre une nouvelle de de lecture des territoires et de ses transformations, en prônant le modèle de la ville compacte et son corollaire la densification, la traduction à donner à ce principe stratégique reste controversée, notamment sous l'angle de l'aménagement du territoire et des stratégies de développement urbain permettant une mise en oeuvre adéquate des solutions proposées. Nous avons ainsi tenté dans ce travail de répondre à un certain nombre de questions : quelle validité accorder au modèle de la ville compacte ? La densification est-elle une réponse adéquate ? Si oui, sous quelles modalités ? Quelles sont, en termes de stratégies d'aménagement, les alternatives durables au modèle de la ville étalée ? Faut-il vraiment densifier ou simplement maîtriser la dispersion ? Notre objectif principal étant in fine de déterminer les orientations et contenus urbanistiques de politiques publiques visant à réguler l'étalement urbain, de valider la faisabilité de ces principes et à définir les conditions de leur mise en place dans le cas d'une agglomération. Pour cela, et après avoir choisi l'agglomération lausannoise comme terrain d'expérimentation, trois approches complémentaires se sont révélées indispensables dans ce travail 1. une approche théorique visant à définir un cadre conceptuel interdisciplinaire d'analyse du phénomène urbain dans ses rapports à la problématique du développement durable liant régime d'urbanisation - forme urbaine - développement durable ; 2. une approche méthodologique proposant des outils d'analyse simples et efficaces de description des nouvelles morphologies urbaines pour une meilleure gestion de l'environnement urbain et de la pratique de l'aménagement urbain ; 3. une approche pragmatique visant à approfondir la réflexion sur la ville étalée en passant d'une approche descriptive des conséquences du nouveau régime d'urbanisation à une approche opérationnelle, visant à identifier les lignes d'actions possibles dans une perspective de développement durable. Cette démarche d'analyse nous a conduits à trois résultats majeurs, nous permettant de définir une stratégie de lutte contre l'étalement. Premièrement, si la densification est acceptée comme un objectif stratégique de l'aménagement urbain, le modèle de la ville dense ne peut être appliqué saris la prise en considération d'autres objectifs d'aménagement. Il ne suffit pas de densifier pour réduire l'empreinte écologique de la ville et améliorer la qualité de vie des citadins. La recherche d'une forme urbaine plus durable est tributaire d'une multiplicité de facteurs et d'effets de synergie et la maîtrise des effets négatifs de l'étalement urbain passe par la mise en oeuvre de politiques urbaines intégrées et concertées, comme par exemple prôner la densification qualifiée comme résultante d'un processus finalisé, intégrer et valoriser les transports collectifs et encore plus la métrique pédestre avec l'aménagement urbain, intégrer systématiquement la diversité à travers les dimensions physique et sociale du territoire. Deuxièmement, l'avenir de ces territoires étalés n'est pas figé. Notre enquête de terrain a montré une évolution des modes d'habitat liée aux modes de vie, à l'organisation du travail, à la mobilité, qui font que l'on peut penser à un retour d'une partie de la population dans les villes centres (fin de la toute puissance du modèle de la maison individuelle). Ainsi, le diagnostic et la recherche de solutions d'aménagement efficaces et viables ne peuvent être dissociés des demandes des habitants et des comportements des acteurs de la production du cadre bâti. Dans cette perspective, tout programme d'urbanisme doit nécessairement s'appuyer sur la connaissance des aspirations de la population. Troisièmement, la réussite de la mise en oeuvre d'une politique globale de maîtrise des effets négatifs de l'étalement urbain est fortement conditionnée par l'adaptation de l'offre immobilière à la demande de nouveaux modèles d'habitat répondant à la fois à la nécessité d'une maîtrise des coûts de l'urbanisation (économiques, sociaux, environnementaux), ainsi qu'aux aspirations émergentes des ménages. Ces résultats nous ont permis de définir les orientations d'une stratégie de lutte contre l'étalement, dont nous avons testé la faisabilité ainsi que les conditions de mise en oeuvre sur le territoire de l'agglomération lausannoise. Abstract This dissertation participates in the perspective of a strategic analysis aiming at specifying the links between knowledge, expertise and political decision, The fundamental hypothesis directing this study assumes that the urban dynamics that has characterized the past thirty years signifies a trans-formation of the morphogenetic principle of agglomerations' spatial development that results in a worsening of their ecological balance and of city dwellers' quality of life. The environmental implications linked to urban changes and particularly to changes in urban form constitute an ever greater share of research into sustainable urban planning solutions. In this context, urban planning becomes a mode of action and an essential component of public policies aiming at local and global sustainable development. These patterns of spatial development indisputably emerge at the heart of environmental issues. If the concept of sustainable development provides us with new understanding into territories and their transformations, by arguing in favor of densification, its concretization remains at issue, especially in terms of urban planning and of urban development strategies allowing the appropriate implementations of the solutions offered. Thus, this study tries to answer a certain number of questions: what validity should be granted to the model of the dense city? Is densification an adequate answer? If so, under what terms? What are the sustainable alternatives to urban sprawl in terms of planning strategies? Should densification really be pursued or should we simply try to master urban sprawl? Our main objective being in fine to determine the directions and urban con-tents of public policies aiming at regulating urban sprawl, to validate the feasibility of these principles and to define the conditions of their implementation in the case of one agglomeration. Once the Lausanne agglomeration had been chosen as experimentation field, three complementary approaches proved to be essential to this study: 1. a theoretical approach aiming at definying an interdisciplinary conceptual framework of the ur-ban phenomenon in its relation to sustainable development linking urban dynamics - urban form - sustainable development ; 2. a methodological approach proposing simple and effective tools for analyzing and describing new urban morphologies for a better management of the urban environment and of urban planning practices 3. a pragmatic approach aiming at deepening reflection on urban sprawl by switching from a descriptive approach of the consequences of the new urban dynamics to an operational approach, aiming at identifying possible avenues of action respecting the principles of sustainable development. This analysis approach provided us with three major results, allowing us to define a strategy to cur-tail urban sprawl. First, if densification is accepted as a strategic objective of urban planning, the model of the dense city can not be applied without taking into consideration other urban planning objectives. Densification does not suffice to reduce the ecological impact of the city and improve the quality of life of its dwellers. The search for a more sustainable urban form depends on a multitude of factors and effects of synergy. Reducing the negative effects of urban sprawl requires the implementation of integrated and concerted urban policies, like for example encouraging densification qualified as resulting from a finalized process, integrating and developing collective forms of transportation and even more so the pedestrian metric with urban planning, integrating diversity on a systematic basis through the physical and social dimensions of the territory. Second, the future of such sprawling territories is not fixed. Our research on the ground revea-led an evolution in the modes of habitat related to ways of life, work organization and mobility that suggest the possibility of the return of a part of the population to the center of cities (end of the rule of the model of the individual home). Thus, the diagnosis and the search for effective and sustainable solutions can not be conceived of independently of the needs of the inhabitants and of the behavior of the actors behind the production of the built territory. In this perspective, any urban program must necessarily be based upon the knowledge of the population's wishes. Third, the successful implementation of a global policy of control of urban sprawl's negative effects is highly influenced by the adaptation of property offer to the demand of new habitat models satisfying both the necessity of urbanization cost controls (economical, social, environ-mental) and people's emerging aspirations. These results allowed us to define a strategy to cur-tail urban sprawl. Its feasibility and conditions of implementation were tested on the territory of the Lausanne agglomeration.
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High-energy charged particles in the van Allen radiation belts and in solar energetic particle events can damage satellites on orbit leading to malfunctions and loss of satellite service. Here we describe some recent results from the SPACECAST project on modelling and forecasting the radiation belts, and modelling solar energetic particle events. We describe the SPACECAST forecasting system that uses physical models that include wave-particle interactions to forecast the electron radiation belts up to 3 h ahead. We show that the forecasts were able to reproduce the >2 MeV electron flux at GOES 13 during the moderate storm of 7-8 October 2012, and the period following a fast solar wind stream on 25-26 October 2012 to within a factor of 5 or so. At lower energies of 10- a few 100 keV we show that the electron flux at geostationary orbit depends sensitively on the high-energy tail of the source distribution near 10 RE on the nightside of the Earth, and that the source is best represented by a kappa distribution. We present a new model of whistler mode chorus determined from multiple satellite measurements which shows that the effects of wave-particle interactions beyond geostationary orbit are likely to be very significant. We also present radial diffusion coefficients calculated from satellite data at geostationary orbit which vary with Kp by over four orders of magnitude. We describe a new automated method to determine the position at the shock that is magnetically connected to the Earth for modelling solar energetic particle events and which takes into account entropy, and predict the form of the mean free path in the foreshock, and particle injection efficiency at the shock from analytical theory which can be tested in simulations.
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It has been shown previously that the endogenous opioid system may be involved in the behavioral effects of nicotine. In the present study, the participation of endogenous enkephalins on nicotine responses has been investigated by using preproenkephalin knock-out mice. Acute nicotine-induced hypolocomotion remained unaffected in these mice. In contrast, antinociception elicited in the tail-immersion and hot-plate tests by acute nicotine administration was reduced in mutant animals. The rewarding properties of nicotine were then investigated using the place-conditioning paradigm. Nicotine induced a conditioned place preference in wild-type animals, but this effect was absent in knock-out mice. Accordingly, in vivo microdialysis studies revealed that the enhancement in dopamine extracellular levels in the nucleus accumbens induced by nicotine was also reduced in preproenkephalin-deficient mice. Finally, the somatic expression of the nicotine withdrawal syndrome precipitated in nicotine-dependent mice by mecamylamine was significantly attenuated in mutant animals. In summary, the present results indicate that endogenous opioid peptides derived from preproenkephalin are involved in the antinociceptive and rewarding properties of nicotine and participate in the expression of physical nicotine dependence.
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The final year project came to us as an opportunity to get involved in a topic which has appeared to be attractive during the learning process of majoring in economics: statistics and its application to the analysis of economic data, i.e. econometrics.Moreover, the combination of econometrics and computer science is a very hot topic nowadays, given the Information Technologies boom in the last decades and the consequent exponential increase in the amount of data collected and stored day by day. Data analysts able to deal with Big Data and to find useful results from it are verydemanded in these days and, according to our understanding, the work they do, although sometimes controversial in terms of ethics, is a clear source of value added both for private corporations and the public sector. For these reasons, the essence of this project is the study of a statistical instrument valid for the analysis of large datasets which is directly related to computer science: Partial Correlation Networks.The structure of the project has been determined by our objectives through the development of it. At first, the characteristics of the studied instrument are explained, from the basic ideas up to the features of the model behind it, with the final goal of presenting SPACE model as a tool for estimating interconnections in between elements in large data sets. Afterwards, an illustrated simulation is performed in order to show the power and efficiency of the model presented. And at last, the model is put into practice by analyzing a relatively large data set of real world data, with the objective of assessing whether the proposed statistical instrument is valid and useful when applied to a real multivariate time series. In short, our main goals are to present the model and evaluate if Partial Correlation Network Analysis is an effective, useful instrument and allows finding valuable results from Big Data.As a result, the findings all along this project suggest the Partial Correlation Estimation by Joint Sparse Regression Models approach presented by Peng et al. (2009) to work well under the assumption of sparsity of data. Moreover, partial correlation networks are shown to be a very valid tool to represent cross-sectional interconnections in between elements in large data sets.The scope of this project is however limited, as there are some sections in which deeper analysis would have been appropriate. Considering intertemporal connections in between elements, the choice of the tuning parameter lambda, or a deeper analysis of the results in the real data application are examples of aspects in which this project could be completed.To sum up, the analyzed statistical tool has been proved to be a very useful instrument to find relationships that connect the elements present in a large data set. And after all, partial correlation networks allow the owner of this set to observe and analyze the existing linkages that could have been omitted otherwise.
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The RAD52 epistasis group was identified in yeast as a group of genes required to repair DNA damaged by ionizing radiation [1]. Genetic evidence indicates that Rad52 functions in Rad51-dependent and Rad51-independent recombination pathways [2] [3] [4]. Consistent with this, purified yeast and human Rad52 proteins have been shown to promote single-strand DNA annealing [5] [6] [7] and to stimulate Rad51-mediated homologous pairing [8] [9] [10] [11]. Electron microscopic examinations of the yeast [12] and human [13] Rad52 proteins have revealed their assembly into ring-like structures in vitro. Using both conventional transmission electron microscopy and scanning transmission electron microscopy (STEM), we found that the human Rad52 protein forms heptameric rings. A three-dimensional (3D) reconstruction revealed that the heptamer has a large central channel. Like the hexameric helicases such as Escherichia coli DnaB [14] [15], bacteriophage T7 gp4b [16] [17], simian virus 40 (SV40) large T antigen [18] and papilloma virus E1 [19], the Rad52 rings show a distinctly chiral arrangement of subunits. Thus, the structures formed by the hexameric helicases may be a more general property of other proteins involved in DNA metabolism, including those, such as Rad52, that do not bind and hydrolyze ATP.
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The wild-type canine distemper virus (CDV) strain A75/17 induces a non-cytocidal infection in cultures of canine footpad keratinocytes (CFKs) but produces very little progeny virus. After only three passages in CFKs, the virus produced 100-fold more progeny and induced a limited cytopathic effect. Sequence analysis of the CFK-adapted virus revealed only three amino acid differences, of which one was located in each the P/V/C, M and H proteins. In order to assess which amino acid changes were responsible for the increase of infectious virus production and altered phenotype of infection, we generated a series of recombinant viruses. Their analysis showed that the altered P/V/C proteins were responsible for the higher levels of virus progeny formation and that the amino acid change in the cytoplasmic tail of the H protein was the major determinant of cytopathogenicity.
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High-energy charged particles in the van Allen radiation belts and in solar energetic particle events can damage satellites on orbit leading to malfunctions and loss of satellite service. Here we describe some recent results from the SPACECAST project on modelling and forecasting the radiation belts, and modelling solar energetic particle events. We describe the SPACECAST forecasting system that uses physical models that include wave-particle interactions to forecast the electron radiation belts up to 3 h ahead. We show that the forecasts were able to reproduce the >2 MeV electron flux at GOES 13 during the moderate storm of 7-8 October 2012, and the period following a fast solar wind stream on 25-26 October 2012 to within a factor of 5 or so. At lower energies of 10- a few 100 keV we show that the electron flux at geostationary orbit depends sensitively on the high-energy tail of the source distribution near 10 RE on the nightside of the Earth, and that the source is best represented by a kappa distribution. We present a new model of whistler mode chorus determined from multiple satellite measurements which shows that the effects of wave-particle interactions beyond geostationary orbit are likely to be very significant. We also present radial diffusion coefficients calculated from satellite data at geostationary orbit which vary with Kp by over four orders of magnitude. We describe a new automated method to determine the position at the shock that is magnetically connected to the Earth for modelling solar energetic particle events and which takes into account entropy, and predict the form of the mean free path in the foreshock, and particle injection efficiency at the shock from analytical theory which can be tested in simulations.
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Congenital myasthenic syndromes (CMS) are clinically and genetically heterogeneous inherited disorders characterized by impaired neuromuscular transmission. Mutations in the acetylcholinesterase (AChE) collagen-like tail subunit gene (COlQ) cause recessive forms of synaptic CMS with end plate AChE deficiency. We present data on 15 COLQ -mutant CMS carrying 16 different mutations (9 novel ones identified) followed-up for an average period of 10 ears. The mean age at the first examination was 19 ears old (range from 3 to 48). We report relapses during short or long-term periods characterized by worsening of muscle weakness sometimes associated with respiratory crises. All the relapses ended spontaneously or with 3-4 DAP or ephedrine with no residual impairment. The triggering factors identified were esterase inhibitors, effort, puberty or pregnancy highlighting the importance of hormonal factors. There was no genotype-phenotype correlation. At the end of the follow-up, 80% of patients were ambulant and 87% of patients had no respiratory trouble in spite of severe relapses.
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In this thesis, I develop analytical models to price the value of supply chain investments under demand uncer¬tainty. This thesis includes three self-contained papers. In the first paper, we investigate the value of lead-time reduction under the risk of sudden and abnormal changes in demand forecasts. We first consider the risk of a complete and permanent loss of demand. We then provide a more general jump-diffusion model, where we add a compound Poisson process to a constant-volatility demand process to explore the impact of sudden changes in demand forecasts on the value of lead-time reduction. We use an Edgeworth series expansion to divide the lead-time cost into that arising from constant instantaneous volatility, and that arising from the risk of jumps. We show that the value of lead-time reduction increases substantially in the intensity and/or the magnitude of jumps. In the second paper, we analyze the value of quantity flexibility in the presence of supply-chain dis- intermediation problems. We use the multiplicative martingale model and the "contracts as reference points" theory to capture both positive and negative effects of quantity flexibility for the downstream level in a supply chain. We show that lead-time reduction reduces both supply-chain disintermediation problems and supply- demand mismatches. We furthermore analyze the impact of the supplier's cost structure on the profitability of quantity-flexibility contracts. When the supplier's initial investment cost is relatively low, supply-chain disin¬termediation risk becomes less important, and hence the contract becomes more profitable for the retailer. We also find that the supply-chain efficiency increases substantially with the supplier's ability to disintermediate the chain when the initial investment cost is relatively high. In the third paper, we investigate the value of dual sourcing for the products with heavy-tailed demand distributions. We apply extreme-value theory and analyze the effects of tail heaviness of demand distribution on the optimal dual-sourcing strategy. We find that the effects of tail heaviness depend on the characteristics of demand and profit parameters. When both the profit margin of the product and the cost differential between the suppliers are relatively high, it is optimal to buffer the mismatch risk by increasing both the inventory level and the responsive capacity as demand uncertainty increases. In that case, however, both the optimal inventory level and the optimal responsive capacity decrease as the tail of demand becomes heavier. When the profit margin of the product is relatively high, and the cost differential between the suppliers is relatively low, it is optimal to buffer the mismatch risk by increasing the responsive capacity and reducing the inventory level as the demand uncertainty increases. In that case, how¬ever, it is optimal to buffer with more inventory and less capacity as the tail of demand becomes heavier. We also show that the optimal responsive capacity is higher for the products with heavier tails when the fill rate is extremely high.
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Combination therapy may improve the outcome of Streptococcus pneumoniae-induced bacteraemia. Here we tested the combination of two antipneumococcal agents, daptomycin and Cpl-1 (the pneumococcal Cp-1 bacteriophage lysin), in a mouse model of pneumococcal bacteraemia. Mice were challenged intraperitoneally (i.p.) with 10(6)CFU of the extremely virulent serotype 2 S. pneumoniae D39 isolate. Subtherapeutic doses of daptomycin (0.4mg/kg) and Cpl-1 (0.4mg/kg and 1mg/kg) were administrated i.p. either alone or in combination by a single bolus injection 1h after bacterial challenge. Survival rates of animals were followed over a period of 7 days. Daptomycin (0.4mg/kg) in combination with Cpl-1 (0.4mg/kg) significantly increased the percentage of surviving mice at Day 7 (80%) compared with the untreated control (0%) and daptomycin or Cpl-1 monotherapy (35% and 0%, respectively). Whilst increasing the concentration of Cpl-1 to 1.0mg/kg did not improve survival when injected alone, its combination with 0.4mg/kg daptomycin further increased the survival rate to 95%. Thus, it was found that the combination of daptomycin with Cpl-1 was synergistic and bactericidal against S. pneumoniae in a mouse model of pneumococcal bacteraemia. To our knowledge, this is the first report of synergism between daptomycin and a phage lysin demonstrated in vivo. Such a combination could represent an interesting alternative therapy for the treatment of pneumococcal bacteraemia/sepsis and possibly other severe pneumococcal infections.
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Using the yeast two-hybrid system, we identified the mu 2 subunit of the clathrin adaptor complex 2 as a protein interacting with the C-tail of the alpha 1b-adrenergic receptor (AR). Direct association between the alpha 1b-AR and mu 2 was demonstrated using a solid phase overlay assay. The alpha 1b-AR/mu 2 interaction occurred inside the cells, as shown by the finding that the transfected alpha 1b-AR and the endogenous mu 2 could be coimmunoprecipitated from HEK-293 cell extracts. Mutational analysis of the alpha 1b-AR revealed that the binding site for mu 2 does not involve canonical YXX Phi or dileucine motifs but a stretch of eight arginines on the receptor C-tail. The binding domain of mu 2 for the receptor C-tail involves both its N terminus and the subdomain B of its C-terminal portion. The alpha 1b-AR specifically interacted with mu 2, but not with the mu 1, mu 3, or mu 4 subunits belonging to other AP complexes. The deletion of the mu 2 binding site in the C-tail markedly decreased agonist-induced receptor internalization as demonstrated by confocal microscopy as well as by the results of a surface receptor biotinylation assay. The direct association of the adaptor complex 2 with a G protein-coupled receptor has not been reported so far and might represent a common mechanism underlying clathrin-mediated receptor endocytosis.