Robert Lefkowitz

Overview:

Dr. Lefkowitz’s memoir, A Funny Thing Happened on the Way to Stockholm, recounts his early career as a cardiologist and his transition to biochemistry, which led to his Nobel Prize win.

Robert J. Lefkowitz, M.D. is James B. Duke Professor of Medicine and Professor of Biochemistry and Chemistry at the Duke University Medical Center. He has been an Investigator of the Howard Hughes Medical Institute since 1976. Dr. Lefkowitz began his research career in the late 1960’s and early 1970’s when there was not a clear consensus that specific receptors for drugs and hormones even existed. His group spent 15 difficult years developing techniques for labeling the receptors with radioactive drugs and then purifying the four different receptors that were known and thought to exist for adrenaline, so called adrenergic receptors. In 1986 Dr. Lefkowitz transformed the understanding of what had by then become known as G protein coupled receptors because of the way the receptor signal for the inside of a cell through G proteins, when he and his colleagues cloned the gene for the beta2-adrenergic receptor. They immediately recognized the similarity to a molecule called rhodopsin which is essentially a light receptor in the retina. This unexpected finding established the beta receptor and rhodopsin as the first member of a new family of proteins. Because each has a peptide structure, which weaves across the cell membrane seven times, these receptors are referred to as seven transmembrane receptors. This super family is now known to be the largest, most diverse and most therapeutically accessible of all the different kinds of cellular receptors. There are almost a thousand members of this receptor family and they regulate virtually all known physiological processes in humans. They include the receptors not only to numerous hormones and neurotransmitters but for the receptors which mediate the senses of sweet and bitter taste and smell amongst many others. Dr. Lefkowitz also discovered the mechanism by which receptor signaling is turned off, a process known as desensitization. Dr. Lefkowitz work was performed at the most fundamental and basic end of the research spectrum and has had remarkable consequences for clinical medicine. Today, more than half of all prescription drug sales are of drugs that target either directly or indirectly the receptors discovered by Dr. Lefkowitz and his trainees. These include amongst many others beta blockers, angiotensin receptor blockers or ARBs and antihistamines. Over the past decade he has discovered novel mechanisms by which the receptors function which may lead to the development of an entirely new class of drugs called “biased agonists”. Several such compounds are already in advanced stages of clinical testing. Dr. Lefkowitz has received numerous honors and awards, including the National Medal of Science, the Shaw Prize, the Albany Prize, and the 2012 Nobel Prize in Chemistry. He was elected to the USA National Academy of Sciences in 1988, the Institute of Medicine in 1994, and the American Academy of Arts and Sciences in 1988.

Positions:

James B. Duke Distinguished Professor of Medicine

Medicine, Cardiology
School of Medicine

Professor of Medicine

Medicine, Cardiology
School of Medicine

Professor of Biochemistry

Biochemistry
School of Medicine

Professor of Pathology

Pathology
School of Medicine

Professor of Chemistry

Chemistry
Trinity College of Arts & Sciences

Associate of the Duke Initiative for Science & Society

Duke Science & Society
Institutes and Provost's Academic Units

Member of the Duke Cancer Institute

Duke Cancer Institute
School of Medicine

Education:

M.D. 1966

Columbia University

Intern, Medicine

Columbia University

Resident, Medicine

Columbia University

Resident, Medicine

Massachusetts General Hospital

Publications:

Abstract MP133: Development of β-arrestin-biased Positive Allosteric Modulators for the β
1
Adrenergic Receptor

<jats:p> The β <jats:sub>1</jats:sub> adrenergic receptor (β <jats:sub>1</jats:sub> AR) is a central regulator of cardiac function and an important therapeutic target for cardiac diseases. Two emerging areas of receptor biology are biased agonism: ligand directed selective engagement of a receptor toward either a G protein or β-arrestin transducer; and allosteric modulation: ligands that bind to topographically distinct sites on the receptor to modulate its activity. Advances in these areas have the potential to yield new drugs that precisely enhance cardioprotective effects while limiting untoward detrimental actions. </jats:p> <jats:p> Compound 6 (Cmpd6) is a newly discovered positive allosteric modulator (PAM) for the β <jats:sub>2</jats:sub> AR. Interestingly, we now show that Cmpd6 has the unique property to enhance the binding affinity of the β-arrestin-biased agonist carvedilol to both the β <jats:sub>2</jats:sub> AR and the β <jats:sub>1</jats:sub> AR, while having minimal effect on the affinity of a panel of agonists and antagonists of the β <jats:sub>1</jats:sub> AR. We further tested the effect of Cmpd6 on β <jats:sub>1</jats:sub> AR signaling induced by a broad range of ligands. Cmpd6 selectively enhanced carvedilol-stimulated ERK activation in a β-arrestin-dependent signaling fashion, while having no effect on carvedilol-induced G protein-dependent cAMP production. </jats:p> <jats:p> To test the <jats:italic>in vivo</jats:italic> effect of Cmpd6 on cardiac injury, mice were pretreated with carvedilol with or without Cmpd6, then underwent ischemia/reperfusion through the left anterior descending artery ligation. Cell apoptosis was assessed by TUNEL. Carvedilol decreased the level of I/R-induced apoptosis compared to the vehicle-treated animals, and Cmpd6 significantly positively enhanced the anti-apoptotic effects of carvedilol. </jats:p> <jats:p> In conclusion, we identified Cmpd6 as a potential β-arrestin-biased PAM for the β <jats:sub>1</jats:sub> AR that enhances the cardioprotective effect of carvedilol. Ongoing studies will test Cmpd6 on heart failure post myocardial infarction. </jats:p>
Authors
Wang, J; Gokhan, I; Xiong, X; Kahsai, AW; Jiang, H; Pfeiffer, CT; Tian, W; Pani, B; Ahn, S; Lefkowitz, RJ; Rockman, HA
MLA Citation
Wang, Jialu, et al. “Abstract MP133: Development of β-arrestin-biased Positive Allosteric Modulators for the β 1 Adrenergic Receptor.” Circulation Research, vol. 127, no. Suppl_1, Ovid Technologies (Wolters Kluwer Health), 2020. Crossref, doi:10.1161/res.127.suppl_1.mp133.
URI
https://scholars.duke.edu/individual/pub1474037
Source
crossref
Published In
Circulation Research
Volume
127
Published Date
DOI
10.1161/res.127.suppl_1.mp133

Unique Positive Cooperativity Between the β-Arrestin-Biased β-Blocker Carvedilol and a Small Molecule Positive Allosteric Modulator of the β2-Adrenergic Receptor.

Among β-blockers that are clinically prescribed for heart failure, carvedilol is a first-choice agent with unique pharmacological properties. Carvedilol is distinct from other β-blockers in its ability to elicit β-arrestin-biased agonism, which has been suggested to underlie its cardioprotective effects. Augmenting the pharmacologic properties of carvedilol thus holds the promise of developing more efficacious and/or biased β-blockers. We recently identified compound-6 (cmpd-6), the first small molecule positive allosteric modulator of the β2-adrenergic receptor (β2AR). Cmpd-6 is positively cooperative with orthosteric agonists at the β2AR and enhances agonist-mediated transducer (G-protein and β-arrestin) signaling in an unbiased manner. Here, we report that cmpd-6, quite unexpectedly, displays strong positive cooperativity only with carvedilol among a panel of structurally diverse β-blockers. Cmpd-6 enhances the binding affinity of carvedilol for the β2AR and augments its ability to competitively antagonize agonist-induced cAMP generation. Cmpd-6 potentiates β-arrestin1- but not Gs-protein-mediated high-affinity binding of carvedilol at the β2AR and β-arrestin-mediated cellular functions in response to carvedilol including extracellular signal-regulated kinase phosphorylation, receptor endocytosis, and trafficking into lysosomes. Importantly, an analog of cmpd-6 that selectively retains positive cooperativity with carvedilol acts as a negative modulator of agonist-stimulated β2AR signaling. These unprecedented cooperative properties of carvedilol and cmpd-6 have implications for fundamental understanding of G-protein-coupled receptor (GPCR) allosteric modulation, as well as for the development of more effective biased beta blockers and other GPCR therapeutics. SIGNIFICANCE STATEMENT: This study reports on the small molecule-mediated allosteric modulation of the β-arrestin-biased β-blocker, carvedilol. The small molecule, compound-6 (cmpd-6), displays an exclusive positive cooperativity with carvedilol among other β-blockers and enhances the binding affinity of carvedilol for the β2-adrenergic receptor. Cooperative effects of cmpd-6 augment the β-blockade property of carvedilol while potentiating its β-arrestin-mediated signaling functions. These findings have potential implications in advancing G-protein-coupled receptor allostery, developing biased therapeutics and remedying cardiovascular ailments.
Authors
Pani, B; Ahn, S; Rambarat, PK; Vege, S; Kahsai, AW; Liu, A; Valan, BN; Staus, DP; Costa, T; Lefkowitz, RJ
MLA Citation
Pani, Biswaranjan, et al. “Unique Positive Cooperativity Between the β-Arrestin-Biased β-Blocker Carvedilol and a Small Molecule Positive Allosteric Modulator of the β2-Adrenergic Receptor.Mol Pharmacol, vol. 100, no. 5, Nov. 2021, pp. 513–25. Pubmed, doi:10.1124/molpharm.121.000363.
URI
https://scholars.duke.edu/individual/pub1497867
PMID
34580163
Source
pubmed
Published In
Mol Pharmacol
Volume
100
Published Date
Start Page
513
End Page
525
DOI
10.1124/molpharm.121.000363

The GPCR-β-arrestin complex allosterically activates C-Raf by binding its amino-terminus.

G protein-coupled receptors (GPCRs) convert external stimuli into cellular signals through heterotrimeric G-proteins and β-arrestins (βarrs). In a βarr-dependent signaling pathway, βarrs link GPCRs to various downstream signaling partners, such as the Raf-MEK-ERK mitogen-activated protein kinase (MAPK) cascade. Agonist-stimulated GPCR-βarr complexes have been shown to interact with C-Raf and are thought to initiate the MAPK pathway through simple tethering of these signaling partners. However, recent evidence shows that in addition to canonical scaffolding functions, βarrs can allosterically activate downstream targets, such as the non-receptor tyrosine kinase Src. Here, we demonstrate the direct allosteric activation of C-Raf by GPCR-βarr1 complexes in vitro. Furthermore, we show that βarr1 in complex with a synthetic phosphopeptide mimicking the human V2 vasopressin receptor tail that binds and functionally activates βarrs also allosterically activates C-Raf. We reveal that the interaction between the phosphorylated GPCR C-terminus and βarr1 is necessary and sufficient for C-Raf activation. Interestingly, the interaction between βarr1 and C-Raf was considerably reduced in the presence of excess activated H-Ras, a small GTPase known to activate C-Raf, suggesting that H-Ras and βarr1 bind to the same region on C-Raf. Furthermore, we found that βarr1 interacts with the Ras-binding domain of C-Raf. Taken together, these data suggest that in addition to canonical scaffolding functions, GPCR-βarr complexes directly allosterically activate C-Raf by binding to its amino-terminus. This work provides novel insights into how βarrs regulate effector molecules to activate downstream signaling pathways.
Authors
Zang, Y; Kahsai, AW; Pakharukova, N; Huang, L-Y; Lefkowitz, RJ
MLA Citation
Zang, Yunxiang, et al. “The GPCR-β-arrestin complex allosterically activates C-Raf by binding its amino-terminus.J Biol Chem, Oct. 2021, p. 101369. Pubmed, doi:10.1016/j.jbc.2021.101369.
URI
https://scholars.duke.edu/individual/pub1501339
PMID
34757127
Source
pubmed
Published In
The Journal of Biological Chemistry
Published Date
Start Page
101369
DOI
10.1016/j.jbc.2021.101369

β-arrestin-biased allosteric modulator potentiates Carvedilol stimulated β adrenergic receptor cardioprotection.

β<sub>1</sub> adrenergic receptors (β<sub>1</sub>ARs) are central regulators of cardiac function and a drug target for cardiac disease. As a member of G protein-coupled receptor family, β<sub>1</sub>ARs activate cellular signaling by primarily coupling to Gs proteins to activate adenylyl cyclase and cAMP-dependent pathways, and the multifunctional adaptor-transducer protein β-arrestin. Carvedilol, a traditional β-blocker widely used in treating high blood pressure and heart failure by blocking βAR-mediated G-protein activation, can selectively stimulate Gs-independent β-arrestin signaling of βARs, a process known as β-arrestin-biased agonism. Recently a DNA-encoded small molecule library screen against agonist-occupied β<sub>2</sub> adrenergic receptors (β<sub>2</sub>AR) identified Compound-6 (Cmpd-6) to be a positive allosteric modulator for agonists on β<sub>2</sub>ARs. Intriguingly, it was further discovered that Cmpd-6 is positively cooperative with the β-arrestin biased ligand carvedilol at β<sub>2</sub>ARs. Here we describe the surprising finding that at β<sub>1</sub>ARs, unlike the case of β<sub>2</sub>ARs, Cmpd-6 is cooperative <i>only</i> with carvedilol and not agonists. Cmpd-6 increases the binding affinity of carvedilol for β<sub>1</sub>ARs and potentiates carvedilol-stimulated, β-arrestin-dependent β<sub>1</sub>AR signaling such as epidermal growth factor receptor transactivation and extracellular signal-regulated kinase activation, while having no effect on Gs-mediated cAMP generation. In vivo, Cmpd-6 enhances the anti-apoptotic cardioprotective effect of carvedilol in response to myocardial ischemia/reperfusion injury. This anti-apoptotic role of carvedilol is dependent on β-arrestins, since it is lost in mice with myocyte-specific deletion of β-arrestins. Our findings demonstrate that Cmpd-6 is a selective β-arrestin-biased allosteric modulator of β<sub>1</sub>ARs and highlight its potential clinical utility in enhancing carvedilol-mediated cardioprotection against ischemic injury. <b>Significance Statement</b> In this study, we demonstrate the positive cooperativity of Cmpd-6 on β<sub>1</sub>ARs as a β-arrestin-biased positive allosteric modulator. Cmpd-6 selectively enhances the affinity and cellular signaling of carvedilol, a known β-arrestin-biased β-blocker for β<sub>1</sub>ARs, while having minimal effect on other ligands tested. Importantly, Cmpd-6 enhances the β-arrestin-dependent <i>in vivo</i> cardioprotective effect of carvedilol during ischemia/reperfusion injury-induced apoptosis. Our data support the potential therapeutic application of Cmpd-6 to enhance the clinical benefits of carvedilol in the treatment of cardiac disease.
Authors
Wang, J; Pani, B; Gokhan, I; Xiong, X; Kahsai, AW; Jiang, H; Ahn, S; Lefkowitz, RJ; Rockman, HA
MLA Citation
Wang, Jialu, et al. “β-arrestin-biased allosteric modulator potentiates Carvedilol stimulated β adrenergic receptor cardioprotection.Molecular Pharmacology, Sept. 2021. Epmc, doi:10.1124/molpharm.121.000359.
URI
https://scholars.duke.edu/individual/pub1497470
PMID
34561298
Source
epmc
Published In
Molecular Pharmacology
Published Date
DOI
10.1124/molpharm.121.000359

RECONSTITUTION OF THE INHIBITORY EFFECTS OF NI AND TRANSDUCIN ON ADENYLATE-CYCLASE ACTIVITY IN PHOSPHOLIPID-VESICLES

Authors
CERIONE, R; KILPATRICK, B; STANISZEWSKI, C; CODINA, J; GIERSCHIK, P; SOMERS, R; SPIEGEL, A; BIRNBAUMER, L; CARON, M; LEFKOWITZ, R
MLA Citation
CERIONE, R., et al. “RECONSTITUTION OF THE INHIBITORY EFFECTS OF NI AND TRANSDUCIN ON ADENYLATE-CYCLASE ACTIVITY IN PHOSPHOLIPID-VESICLES.” Federation Proceedings, vol. 44, no. 3, 1985, pp. 699–699.
URI
https://scholars.duke.edu/individual/pub865632
Source
wos-lite
Published In
Federation Proceedings
Volume
44
Published Date
Start Page
699
End Page
699