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Robert J. Lefkowitz

Bio: Robert J. Lefkowitz is an academic researcher from Howard Hughes Medical Institute. The author has contributed to research in topics: Receptor & G protein-coupled receptor. The author has an hindex of 214, co-authored 860 publications receiving 147995 citations. Previous affiliations of Robert J. Lefkowitz include University of Nice Sophia Antipolis & University of Stuttgart.


Papers
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Journal ArticleDOI
13 Aug 1993-Cell
TL;DR: This review focuses on the regulation of GRK activity by a variety of allosteric and other factors: agonist-stimulated GPCRs, fl∞ subunits of heterotrimeric GTP- binding proteins, phospholipid cofactors, the calcium-binding proteins calmodulin and recoverin, posttranslational isoprenylation and palmitoylation, autophosphorylation, and protein kinase C‐mediated GRK phosphorylation

434 citations

Journal ArticleDOI
TL;DR: It is concluded that low or high concentrations of agonist elicit phosphorylation of beta 2AR on distinct domains, with different implications for the functional coupling of the receptors with effector molecules.

431 citations

Journal ArticleDOI
TL;DR: In a given cell type, the responsiveness to stimulus, as well as the nature of the response, is dictated by the available complement of receptor, G protein, and effector.
Abstract: I. Introduction RECEPTORS coupled to heterotrimeric GTP-binding proteins (G proteins) comprise the largest known family of cell surface receptors and mediate cellular responses to a diverse array of signaling molecules, including peptide and glycopeptide hormones, neurotransmitters, phospholipids, odorants, and photons. The basic unit of G protein-coupled receptor (GPCR) signaling is comprised of three parts; receptor, which detects ligand in the extracellular milieu; heterotrimeric G protein, which is dissociated into active Gα-GTP and Gβγ-subunits after interaction with the liganded receptor; and effector, which interacts with dissociated Gα-GTP and Gβγ-subunits to mediate the intracellular effects of ligand binding. In a given cell type, the responsiveness to stimulus, as well as the nature of the response, is dictated by the available complement of receptor, G protein, and effector. Despite the diverse array of ligands with which they interact, GPCRs share a conserved predicted tertiary structure char...

431 citations

Journal ArticleDOI
13 Oct 1989-Science
TL;DR: Genomic DNA blot analysis suggests that beta-ARK may be the first sequenced member of a multigene family of receptor kinases, and appears to be important in mediating rapid agonist-specific (homologous) desensitization.
Abstract: The beta-adrenergic receptor kinase (beta-ARK), which specifically phosphorylates only the agonist-occupied form of the beta-adrenergic and closely related receptors, appears to be important in mediating rapid agonist-specific (homologous) desensitization. The structure of this enzyme was elucidated by isolating clones from a bovine brain complementary DNA library through the use of oligonucleotide probes derived from partial amino acid sequence. The beta-ARK cDNA codes for a protein of 689 amino acids (79.7 kilodaltons) with a protein kinase catalytic domain that bears greatest sequence similarity to protein kinase C and the cyclic adenosine monophosphate (cyclic AMP)--dependent protein kinase. When this clone was inserted into a mammalian expression vector and transfected into COS-7 cells, a protein that specifically phosphorylated the agonist-occupied form of the beta 2-adrenergic receptor and phosphorylated, much more weakly, the light-bleached form of rhodopsin was expressed. RNA blot analysis revealed a messenger RNA of four kilobases with highest amounts in brain and spleen. Genomic DNA blot analysis also suggests that beta-ARK may be the first sequenced member of a multigene family of receptor kinases.

430 citations


Cited by
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28 Jul 2005
TL;DR: PfPMP1)与感染红细胞、树突状组胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作�ly.
Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1(PfPMP1)与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员,通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

18,940 citations

Journal ArticleDOI
19 Feb 1998-Nature
TL;DR: To their surprise, it was found that double-stranded RNA was substantially more effective at producing interference than was either strand individually, arguing against stochiometric interference with endogenous mRNA and suggesting that there could be a catalytic or amplification component in the interference process.
Abstract: Experimental introduction of RNA into cells can be used in certain biological systems to interfere with the function of an endogenous gene Such effects have been proposed to result from a simple antisense mechanism that depends on hybridization between the injected RNA and endogenous messenger RNA transcripts RNA interference has been used in the nematode Caenorhabditis elegans to manipulate gene expression Here we investigate the requirements for structure and delivery of the interfering RNA To our surprise, we found that double-stranded RNA was substantially more effective at producing interference than was either strand individually After injection into adult animals, purified single strands had at most a modest effect, whereas double-stranded mixtures caused potent and specific interference The effects of this interference were evident in both the injected animals and their progeny Only a few molecules of injected double-stranded RNA were required per affected cell, arguing against stochiometric interference with endogenous mRNA and suggesting that there could be a catalytic or amplification component in the interference process

15,374 citations

Journal ArticleDOI
TL;DR: This approach provides two major advantages compared with other available methods: it uses an exact mathematical model of the ligand-binding system, thereby avoiding the possible biases introduced by several commonly used approximations and it uses a statistically valid, appropriately weighted least-squares curve-fitting algorithm with objective measurement of goodness of fit.

8,717 citations

Journal ArticleDOI
13 Oct 2000-Cell
TL;DR: Understanding of the complex signaling networks downstream from RTKs and how alterations in these networks are translated into cellular responses provides an important context for therapeutically countering the effects of pathogenic RTK mutations in cancer and other diseases.

7,056 citations

Journal ArticleDOI
TL;DR: This review considers recent findings regarding GC action and generates criteria for determining whether a particular GC action permits, stimulates, or suppresses an ongoing stress-response or, as an additional category, is preparative for a subsequent stressor.
Abstract: The secretion of glucocorticoids (GCs) is a classic endocrine response to stress. Despite that, it remains controversial as to what purpose GCs serve at such times. One view, stretching back to the time of Hans Selye, posits that GCs help mediate the ongoing or pending stress response, either via basal levels of GCs permitting other facets of the stress response to emerge efficaciously, and/or by stress levels of GCs actively stimulating the stress response. In contrast, a revisionist viewpoint posits that GCs suppress the stress response, preventing it from being pathologically overactivated. In this review, we consider recent findings regarding GC action and, based on them, generate criteria for determining whether a particular GC action permits, stimulates, or suppresses an ongoing stressresponse or, as an additional category, is preparative for a subsequent stressor. We apply these GC actions to the realms of cardiovascular function, fluid volume and hemorrhage, immunity and inflammation, metabolism, neurobiology, and reproductive physiology. We find that GC actions fall into markedly different categories, depending on the physiological endpoint in question, with evidence for mediating effects in some cases, and suppressive or preparative in others. We then attempt to assimilate these heterogeneous GC actions into a physiological whole. (Endocrine Reviews 21: 55‐ 89, 2000)

6,707 citations