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Shi Y, Li J, Kennedy LJ, Tao S, Hernández AS, Lai Z, Chen S, Wong H, Zhu J, Trehan A, Lim NK, Zhang H, Chen BC, Locke KT, O’Malley KM, Zhang L, Srivastava RA, Miao B, Meyers DS, Monshizadegan H, Search D, Grimm D, Zhang R, Harrity T, Kunselman LK, Cap M, Muckelbauer J, Chang C, Krystek SR, Li YX, Hosagrahara V, Zhang L, Kadiyala P, Xu C, Blanar MA, Zahler R, Mukherjee R, Cheng PTW, Tino JA. Discovery and Preclinical Evaluation of BMS-711939, an Oxybenzylglycine Based PPARα Selective Agonist. ACS Med Chem Lett 2016; 7:590-4. [PMID: 27326332 DOI: 10.1021/acsmedchemlett.6b00033] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2016] [Accepted: 04/03/2016] [Indexed: 12/20/2022] Open
Abstract
BMS-711939 (3) is a potent and selective peroxisome proliferator-activated receptor (PPAR) α agonist, with an EC50 of 4 nM for human PPARα and >1000-fold selectivity vs human PPARγ (EC50 = 4.5 μM) and PPARδ (EC50 > 100 μM) in PPAR-GAL4 transactivation assays. Compound 3 also demonstrated excellent in vivo efficacy and safety profiles in preclinical studies and thus was chosen for further preclinical evaluation. The synthesis, structure-activity relationship (SAR) studies, and in vivo pharmacology of 3 in preclinical animal models as well as its ADME profile are described.
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Affiliation(s)
- Yan Shi
- Research
and Development, Bristol-Myers Squibb Company, 350 Carter Road, Hopewell, New Jersey 08540, United States
| | - Jun Li
- Research
and Development, Bristol-Myers Squibb Company, 350 Carter Road, Hopewell, New Jersey 08540, United States
| | - Lawrence J. Kennedy
- Research
and Development, Bristol-Myers Squibb Company, 350 Carter Road, Hopewell, New Jersey 08540, United States
| | - Shiwei Tao
- Research
and Development, Bristol-Myers Squibb Company, 350 Carter Road, Hopewell, New Jersey 08540, United States
| | - Andrés S. Hernández
- Research
and Development, Bristol-Myers Squibb Company, 350 Carter Road, Hopewell, New Jersey 08540, United States
| | - Zhi Lai
- Research
and Development, Bristol-Myers Squibb Company, 350 Carter Road, Hopewell, New Jersey 08540, United States
| | - Sean Chen
- Research
and Development, Bristol-Myers Squibb Company, 350 Carter Road, Hopewell, New Jersey 08540, United States
| | - Henry Wong
- Research
and Development, Bristol-Myers Squibb Company, 350 Carter Road, Hopewell, New Jersey 08540, United States
| | - Juliang Zhu
- Research
and Development, Bristol-Myers Squibb Company, 350 Carter Road, Hopewell, New Jersey 08540, United States
| | - Ashok Trehan
- Research
and Development, Bristol-Myers Squibb Company, 350 Carter Road, Hopewell, New Jersey 08540, United States
| | - Ngiap-Kie Lim
- Research
and Development, Bristol-Myers Squibb Company, 350 Carter Road, Hopewell, New Jersey 08540, United States
| | - Huiping Zhang
- Research
and Development, Bristol-Myers Squibb Company, 350 Carter Road, Hopewell, New Jersey 08540, United States
| | - Bang-Chi Chen
- Research
and Development, Bristol-Myers Squibb Company, 350 Carter Road, Hopewell, New Jersey 08540, United States
| | - Kenneth T. Locke
- Research
and Development, Bristol-Myers Squibb Company, 350 Carter Road, Hopewell, New Jersey 08540, United States
| | - Kevin M. O’Malley
- Research
and Development, Bristol-Myers Squibb Company, 350 Carter Road, Hopewell, New Jersey 08540, United States
| | - Litao Zhang
- Research
and Development, Bristol-Myers Squibb Company, 350 Carter Road, Hopewell, New Jersey 08540, United States
| | - Rai Ajit Srivastava
- Research
and Development, Bristol-Myers Squibb Company, 350 Carter Road, Hopewell, New Jersey 08540, United States
| | - Bowman Miao
- Research
and Development, Bristol-Myers Squibb Company, 350 Carter Road, Hopewell, New Jersey 08540, United States
| | - Daniel S. Meyers
- Research
and Development, Bristol-Myers Squibb Company, 350 Carter Road, Hopewell, New Jersey 08540, United States
| | - Hossain Monshizadegan
- Research
and Development, Bristol-Myers Squibb Company, 350 Carter Road, Hopewell, New Jersey 08540, United States
| | - Debra Search
- Research
and Development, Bristol-Myers Squibb Company, 350 Carter Road, Hopewell, New Jersey 08540, United States
| | - Denise Grimm
- Research
and Development, Bristol-Myers Squibb Company, 350 Carter Road, Hopewell, New Jersey 08540, United States
| | - Rongan Zhang
- Research
and Development, Bristol-Myers Squibb Company, 350 Carter Road, Hopewell, New Jersey 08540, United States
| | - Thomas Harrity
- Research
and Development, Bristol-Myers Squibb Company, 350 Carter Road, Hopewell, New Jersey 08540, United States
| | - Lori K. Kunselman
- Research
and Development, Bristol-Myers Squibb Company, 350 Carter Road, Hopewell, New Jersey 08540, United States
| | - Michael Cap
- Research
and Development, Bristol-Myers Squibb Company, 350 Carter Road, Hopewell, New Jersey 08540, United States
| | - Jodi Muckelbauer
- Research
and Development, Bristol-Myers Squibb Company, 350 Carter Road, Hopewell, New Jersey 08540, United States
| | - Chiehying Chang
- Research
and Development, Bristol-Myers Squibb Company, 350 Carter Road, Hopewell, New Jersey 08540, United States
| | - Stanley R. Krystek
- Research
and Development, Bristol-Myers Squibb Company, 350 Carter Road, Hopewell, New Jersey 08540, United States
| | - Yi-Xin Li
- Research
and Development, Bristol-Myers Squibb Company, 350 Carter Road, Hopewell, New Jersey 08540, United States
| | - Vinayak Hosagrahara
- Research
and Development, Bristol-Myers Squibb Company, 350 Carter Road, Hopewell, New Jersey 08540, United States
| | - Lisa Zhang
- Research
and Development, Bristol-Myers Squibb Company, 350 Carter Road, Hopewell, New Jersey 08540, United States
| | - Pathanjali Kadiyala
- Research
and Development, Bristol-Myers Squibb Company, 350 Carter Road, Hopewell, New Jersey 08540, United States
| | - Carrie Xu
- Research
and Development, Bristol-Myers Squibb Company, 350 Carter Road, Hopewell, New Jersey 08540, United States
| | - Michael A. Blanar
- Research
and Development, Bristol-Myers Squibb Company, 350 Carter Road, Hopewell, New Jersey 08540, United States
| | - Robert Zahler
- Research
and Development, Bristol-Myers Squibb Company, 350 Carter Road, Hopewell, New Jersey 08540, United States
| | - Ranjan Mukherjee
- Research
and Development, Bristol-Myers Squibb Company, 350 Carter Road, Hopewell, New Jersey 08540, United States
| | - Peter T. W. Cheng
- Research
and Development, Bristol-Myers Squibb Company, 350 Carter Road, Hopewell, New Jersey 08540, United States
| | - Joseph A. Tino
- Research
and Development, Bristol-Myers Squibb Company, 350 Carter Road, Hopewell, New Jersey 08540, United States
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Li J, Kennedy LJ, Shi Y, Tao S, Ye XY, Chen SY, Wang Y, Hernández AS, Wang W, Devasthale PV, Chen S, Lai Z, Zhang H, Wu S, Smirk RA, Bolton SA, Ryono DE, Zhang H, Lim NK, Chen BC, Locke KT, O’Malley KM, Zhang L, Srivastava RA, Miao B, Meyers DS, Monshizadegan H, Search D, Grimm D, Zhang R, Harrity T, Kunselman LK, Cap M, Kadiyala P, Hosagrahara V, Zhang L, Xu C, Li YX, Muckelbauer JK, Chang C, An Y, Krystek SR, Blanar MA, Zahler R, Mukherjee R, Cheng PTW, Tino JA. Discovery of an Oxybenzylglycine Based Peroxisome Proliferator Activated Receptor α Selective Agonist 2-((3-((2-(4-Chlorophenyl)-5-methyloxazol-4-yl)methoxy)benzyl)(methoxycarbonyl)amino)acetic Acid (BMS-687453). J Med Chem 2010; 53:2854-64. [DOI: 10.1021/jm9016812] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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3
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Ahmad S, Madsen CS, Stein PD, Janovitz E, Huang C, Ngu K, Bisaha S, Kennedy LJ, Chen BC, Zhao R, Sitkoff D, Monshizadegan H, Yin X, Ryan CS, Zhang R, Giancarli M, Bird E, Chang M, Chen X, Setters R, Search D, Zhuang S, Nguyen-Tran V, Cuff CA, Harrity T, Darienzo CJ, Li T, Reeves RA, Blanar MA, Barrish JC, Zahler R, Robl JA. (3R,5S,E)-7-(4-(4-Fluorophenyl)-6-isopropyl-2-(methyl(1-methyl-1H-1,2,4-triazol-5-yl)amino)pyrimidin-5-yl)-3,5-dihydroxyhept-6-enoic Acid (BMS-644950): A Rationally Designed Orally Efficacious 3-Hydroxy-3-methylglutaryl Coenzyme-A Reductase Inhibitor with Reduced Myotoxicity Potential. J Med Chem 2008; 51:2722-33. [DOI: 10.1021/jm800001n] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Saleem Ahmad
- Bristol-Myers Squibb Research & Development, P.O. Box 4000, Princeton, New Jersey 08543
| | - Cort S. Madsen
- Bristol-Myers Squibb Research & Development, P.O. Box 4000, Princeton, New Jersey 08543
| | - Philip D. Stein
- Bristol-Myers Squibb Research & Development, P.O. Box 4000, Princeton, New Jersey 08543
| | - Evan Janovitz
- Bristol-Myers Squibb Research & Development, P.O. Box 4000, Princeton, New Jersey 08543
| | - Christine Huang
- Bristol-Myers Squibb Research & Development, P.O. Box 4000, Princeton, New Jersey 08543
| | - Khehyong Ngu
- Bristol-Myers Squibb Research & Development, P.O. Box 4000, Princeton, New Jersey 08543
| | - Sharon Bisaha
- Bristol-Myers Squibb Research & Development, P.O. Box 4000, Princeton, New Jersey 08543
| | - Lawrence J. Kennedy
- Bristol-Myers Squibb Research & Development, P.O. Box 4000, Princeton, New Jersey 08543
| | - Bang-Chi Chen
- Bristol-Myers Squibb Research & Development, P.O. Box 4000, Princeton, New Jersey 08543
| | - Rulin Zhao
- Bristol-Myers Squibb Research & Development, P.O. Box 4000, Princeton, New Jersey 08543
| | - Doree Sitkoff
- Bristol-Myers Squibb Research & Development, P.O. Box 4000, Princeton, New Jersey 08543
| | - Hossain Monshizadegan
- Bristol-Myers Squibb Research & Development, P.O. Box 4000, Princeton, New Jersey 08543
| | - Xiaohong Yin
- Bristol-Myers Squibb Research & Development, P.O. Box 4000, Princeton, New Jersey 08543
| | - Carol S. Ryan
- Bristol-Myers Squibb Research & Development, P.O. Box 4000, Princeton, New Jersey 08543
| | - Rongan Zhang
- Bristol-Myers Squibb Research & Development, P.O. Box 4000, Princeton, New Jersey 08543
| | - Mary Giancarli
- Bristol-Myers Squibb Research & Development, P.O. Box 4000, Princeton, New Jersey 08543
| | - Eileen Bird
- Bristol-Myers Squibb Research & Development, P.O. Box 4000, Princeton, New Jersey 08543
| | - Ming Chang
- Bristol-Myers Squibb Research & Development, P.O. Box 4000, Princeton, New Jersey 08543
| | - Xing Chen
- Bristol-Myers Squibb Research & Development, P.O. Box 4000, Princeton, New Jersey 08543
| | - Robert Setters
- Bristol-Myers Squibb Research & Development, P.O. Box 4000, Princeton, New Jersey 08543
| | - Debra Search
- Bristol-Myers Squibb Research & Development, P.O. Box 4000, Princeton, New Jersey 08543
| | - Shaobin Zhuang
- Bristol-Myers Squibb Research & Development, P.O. Box 4000, Princeton, New Jersey 08543
| | - Van Nguyen-Tran
- Bristol-Myers Squibb Research & Development, P.O. Box 4000, Princeton, New Jersey 08543
| | - Carolyn A. Cuff
- Bristol-Myers Squibb Research & Development, P.O. Box 4000, Princeton, New Jersey 08543
| | - Thomas Harrity
- Bristol-Myers Squibb Research & Development, P.O. Box 4000, Princeton, New Jersey 08543
| | - Celia J. Darienzo
- Bristol-Myers Squibb Research & Development, P.O. Box 4000, Princeton, New Jersey 08543
| | - Tong Li
- Bristol-Myers Squibb Research & Development, P.O. Box 4000, Princeton, New Jersey 08543
| | - Richard A. Reeves
- Bristol-Myers Squibb Research & Development, P.O. Box 4000, Princeton, New Jersey 08543
| | - Michael A. Blanar
- Bristol-Myers Squibb Research & Development, P.O. Box 4000, Princeton, New Jersey 08543
| | - Joel C. Barrish
- Bristol-Myers Squibb Research & Development, P.O. Box 4000, Princeton, New Jersey 08543
| | - Robert Zahler
- Bristol-Myers Squibb Research & Development, P.O. Box 4000, Princeton, New Jersey 08543
| | - Jeffrey A. Robl
- Bristol-Myers Squibb Research & Development, P.O. Box 4000, Princeton, New Jersey 08543
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4
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Madsen CS, Janovitz E, Zhang R, Nguyen-Tran V, Ryan CS, Yin X, Monshizadegan H, Chang M, D'Arienzo C, Scheer S, Setters R, Search D, Chen X, Zhuang S, Kunselman L, Peters A, Harrity T, Apedo A, Huang C, Cuff CA, Kowala MC, Blanar MA, Sun CQ, Robl JA, Stein PD. The Guinea pig as a preclinical model for demonstrating the efficacy and safety of statins. J Pharmacol Exp Ther 2007; 324:576-86. [PMID: 17986646 DOI: 10.1124/jpet.107.131615] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Statins, because of their excellent efficacy and manageable safety profile, represent a key component in the current armamentarium for the treatment of hypercholesterolemia. Nonetheless, myopathy remains a safety concern for this important drug class. Cerivastatin was withdrawn from the market for myotoxicity safety concerns. BMS-423526 [{(3R,5S)-7-[4-(4-fluorophenyl)-6,7-dihydro-2-(1-methylethyl)-5H-benzo[6,7]cyclohepta[1,2-b]pyridin-3-yl]-3,5-dihydroxy-heptenoic acid} sodium salt], similar to cerivastatin in potency and lipophilicity, was terminated in early clinical development due to an unacceptable myotoxicity profile. In this report, we describe the guinea pig as a model of statin-induced cholesterol lowering and myotoxicity and show that this model can distinguish statins with unacceptable myotoxicity profiles from statins with acceptable safety profiles. In our guinea pig model, both cerivastatin and BMS-423526 induced myotoxicity at doses near the ED(50) for total cholesterol (TC) lowering in plasma. In contrast, wide differences between myotoxic and TC-lowering doses were established for the currently marketed, more hydrophilic statins, pravastatin, rosuvastatin, and atorvastatin. This in vivo model compared favorably to an in vitro model, which used statin inhibition of cholesterol synthesis in rat hepatocytes and L6 myoblasts as surrogates of potential efficacy and toxicity, respectively. Our conclusion is that the guinea pig is a useful preclinical in vivo model for demonstrating whether a statin is likely to have an acceptable therapeutic safety margin.
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Affiliation(s)
- Cort S Madsen
- Department of Atherosclerosis, Bristol-Myers Squibb Co., 311 Pennington-Rocky Hill Road, Pennington, NJ 08534, USA.
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5
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Lee N, Chen J, Sun L, Wu S, Gray KR, Rich A, Huang M, Lin JH, Feder JN, Janovitz EB, Levesque PC, Blanar MA. Expression and characterization of human transient receptor potential melastatin 3 (hTRPM3). J Biol Chem 2003; 278:20890-7. [PMID: 12672827 DOI: 10.1074/jbc.m211232200] [Citation(s) in RCA: 161] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Transient receptor potential (TRP) cation-selective channels are an emerging class of proteins that are involved in a variety of important biological functions including pain transduction, thermosensation, mechanoregulation, and vasorelaxation. Utilizing a bioinformatics approach, we have identified the full-length human TRPM3 (hTRPM3) as a member of the TRP family. The hTRPM3 gene is comprised of 24 exons and maps to human chromosome 9q-21.12. hTRPM3 is composed of 1555 amino acids and possesses the characteristic six-transmembrane domain of the TRP family. hTRPM3 is expressed primarily in kidney and, at lesser levels, in brain, testis, and spinal cord as demonstrated by quantitative RT-PCR and Northern blotting. In situ hybridization in human kidney demonstrated that hTRPM3 mRNA expression is predominantly found in the collecting tubular epithelium. Heterologous expression of hTRPM3 in human embryonic kidney cells (HEK 293) showed that hTRPM3 is localized to the cell membrane. hTRPM3-expressing cells exhibited Ca2+ concentration-dependent Ca2+ entry. Depletion of intracellular Ca2+ stores by lowering extracellular Ca2+ concentration and treatment with the Ca2+-ATPase inhibitor thapsigargin or the muscarinic receptor agonist carbachol further augmented hTRPM3-mediated Ca2+ entry. The nonselective Ca2+ channel blocker, lanthanide gadolinium (Gd3+), partially inhibited hTRPM3-mediated Ca2+ entry. These results are consistent with the hypothesis that hTRPM3 mediates a Ca2+ entry pathway that apparently is distinct from the endogenous Ca2+ entry pathways present in HEK 293 cells.
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Affiliation(s)
- Ning Lee
- Metabolic and Cardiovascular Diseases Drug Discovery, Pharmaceutical Research Institute, Bristol-Myers Squibb Company, Princeton, New Jersey 08543, USA.
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6
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Shalaby FY, Little WA, Panchal BC, Patton BL, Wang FL, Ciali LB, Ferrer PA, Anthony KB, Green DW, Trippodo NC, Madsen CS, Blanar MA. The role of the mitochondrial ATPase inhibitor, IF1, in cardiac ATP conservation under hypoxic/ischemic conditions. J Mol Cell Cardiol 2001. [DOI: 10.1016/s0022-2828(01)90432-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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7
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Huang L, Sankar S, Lin C, Kontos CD, Schroff AD, Cha EH, Feng SM, Li SF, Yu Z, Van Etten RL, Blanar MA, Peters KG. HCPTPA, a protein tyrosine phosphatase that regulates vascular endothelial growth factor receptor-mediated signal transduction and biological activity. J Biol Chem 1999; 274:38183-8. [PMID: 10608891 DOI: 10.1074/jbc.274.53.38183] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Angiogenesis is a tightly controlled process in which signaling by the receptors for vascular endothelial growth factor (VEGF) plays a key role. In order to define signaling pathways downstream of VEGF receptors (VEGFR), the kinase domain of VEGFR2 (Flk-1) was used as a bait to screen a human fetal heart library in the yeast two-hybrid system. One of the signaling molecules identified in this effort was HCPTPA, a low molecular weight, cytoplasmic protein tyrosine phosphatase. Although HCPTPA possesses no identifiable phosphotyrosine binding domains (i.e. SH2 or phosphotyrosine binding domains), it bound specifically to active, autophosphorylated VEGFR2 but not to a mutated, kinase-inactive VEGFR2. Recombinant VEGFR2 and endogenous VEGFR2 were substrates for recombinant HCPTPA, and HCPTPA was co-expressed with VEGFR2 in endothelial cell lines, suggesting that HCPTPA may be a negative regulator of VEGFR2 signal transduction. To pursue this possibility, an adenovirus directing the expression of HCPTPA was constructed. When used to infect cultured endothelial cells, this adenovirus directed high level expression of HCPTPA that resulted in impairment of VEGF-mediated VEGFR2 autophosphorylation and mitogen-activated protein kinase activation. Adenovirus-mediated overexpression of HCPTPA also inhibited VEGF-induced cellular responses (endothelial cell migration and proliferation) and inhibited angiogenesis in the rat aortic ring assay. Taken together, these findings indicate that HCPTPA may be an important regulator of VEGF-mediated signaling and biological activity. Potential interactions with other signaling pathways and possible therapeutic implications are discussed.
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Affiliation(s)
- L Huang
- Department of Medicine, Duke University Medical Center, Durham, North Carolina 27710, USA
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8
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Yang WP, Levesque PC, Little WA, Conder ML, Ramakrishnan P, Neubauer MG, Blanar MA. Functional expression of two KvLQT1-related potassium channels responsible for an inherited idiopathic epilepsy. J Biol Chem 1998; 273:19419-23. [PMID: 9677360 DOI: 10.1074/jbc.273.31.19419] [Citation(s) in RCA: 151] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Benign familial neonatal convulsions (BFNC), a class of idiopathic generalized epilepsy, is an autosomal dominantly inherited disorder of newborns. BFNC has been linked to mutations in two putative K+ channel genes, KCNQ2 and KCNQ3. Amino acid sequence comparison reveals that both genes share strong homology to KvLQT1, the potassium channel encoded by KCNQ1, which is responsible for over 50% of inherited long QT syndrome. Here we describe the cloning, functional expression, and characterization of K+ channels encoded by KCNQ2 and KCNQ3 cDNAs. Individually, expression of KCNQ2 or KCNQ3 in Xenopus oocytes elicits voltage-gated, rapidly activating K+-selective currents similar to KCNQ1. However, unlike KCNQ1, KCNQ2 and KCNQ3 currents are not augmented by coexpression with the KCNQ1 beta subunit, KCNE1 (minK, IsK). Northern blot analyses reveal that KCNQ2 and KCNQ3 exhibit similar expression patterns in different regions within the brain. Interestingly, coexpression of KCNQ2 and KCNQ3 results in a substantial synergistic increase in current amplitude. Coexpression of KCNE1 with the two channels strongly suppressed current amplitude and slowed kinetics of activation. The pharmacological and biophysical properties of the K+ currents observed in the coinjected oocytes differ somewhat from those observed after injecting either KCNQ2 or KCNQ3 by itself. The functional interaction between KCNQ2 and KCNQ3 provides a framework for understanding how mutations in either channel can cause a form of idiopathic generalized epilepsy.
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Affiliation(s)
- W P Yang
- Department of Cardiovascular Drug Discovery, Bristol-Myers Squibb Pharmaceutical Research Institute, Princeton, New Jersey 08543-4000, USA
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9
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Kontos CD, Stauffer TP, Yang WP, York JD, Huang L, Blanar MA, Meyer T, Peters KG. Tyrosine 1101 of Tie2 is the major site of association of p85 and is required for activation of phosphatidylinositol 3-kinase and Akt. Mol Cell Biol 1998; 18:4131-40. [PMID: 9632797 PMCID: PMC108997 DOI: 10.1128/mcb.18.7.4131] [Citation(s) in RCA: 173] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/1997] [Accepted: 04/28/1998] [Indexed: 02/07/2023] Open
Abstract
Tie2 is an endothelium-specific receptor tyrosine kinase that is required for both normal embryonic vascular development and tumor angiogenesis and is thought to play a role in vascular maintenance. However, the signaling pathways responsible for the function of Tie2 remain unknown. In this report, we demonstrate that the p85 subunit of phosphatidylinositol 3-kinase (PI3-kinase) associates with Tie2 and that this association confers functional lipid kinase activity. Mutation of tyrosine 1101 of Tie2 abrogated p85 association both in vitro and in vivo in yeast. Tie2 was found to activate PI3-kinase in vivo as demonstrated by direct measurement of increases in cellular phosphatidylinositol 3-phosphate and phosphatidylinositol 3, 4-bisphosphate, by plasma membrane translocation of a green fluorescent protein-Akt pleckstrin homology domain fusion protein, and by downstream activation of the Akt kinase. Activation of PI3-kinase was abrogated in these assays by mutation of Y1101 to phenylalanine, consistent with a requirement for this residue for p85 association with Tie2. These results suggest that activation of PI3-kinase and Akt may in part account for Tie2's role in both embryonic vascular development and pathologic angiogenesis, and they are consistent with a role for Tie2 in endothelial cell survival.
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Affiliation(s)
- C D Kontos
- Departments of Medicine, Duke University Medical Center, Durham, North Carolina 27710, USA
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10
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Layne MD, Endege WO, Jain MK, Yet SF, Hsieh CM, Chin MT, Perrella MA, Blanar MA, Haber E, Lee ME. Aortic carboxypeptidase-like protein, a novel protein with discoidin and carboxypeptidase-like domains, is up-regulated during vascular smooth muscle cell differentiation. J Biol Chem 1998; 273:15654-60. [PMID: 9624159 DOI: 10.1074/jbc.273.25.15654] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Phenotypic modulation of vascular smooth muscle cells plays an important role in the pathogenesis of arteriosclerosis. In a screen of proteins expressed in human aortic smooth muscle cells, we identified a novel gene product designated aortic carboxypeptidase-like protein (ACLP). The approximately 4-kilobase human cDNA and its mouse homologue encode 1158 and 1128 amino acid proteins, respectively, that are 85% identical. ACLP is a nonnuclear protein that contains a signal peptide, a lysine- and proline-rich 11-amino acid repeating motif, a discoidin-like domain, and a C-terminal domain with 39% identity to carboxypeptidase E. By Western blot analysis and in situ hybridization, we detected abundant ACLP expression in the adult aorta. ACLP was expressed predominantly in the smooth muscle cells of the adult mouse aorta but not in the adventitia or in several other tissues. In cultured mouse aortic smooth muscle cells, ACLP mRNA and protein were up-regulated 2-3-fold after serum starvation. Using a recently developed neural crest cell to smooth muscle cell in vitro differentiation system, we found that ACLP mRNA and protein were not expressed in neural crest cells but were up-regulated dramatically with the differentiation of these cells. These results indicate that ACLP may play a role in differentiated vascular smooth muscle cells.
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Affiliation(s)
- M D Layne
- Cardiovascular Biology Laboratory, Harvard School of Public Health, Boston, Massachusetts 02115, USA
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11
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Abstract
ATP-sensitive K+ (KATP) channels are implicated in the coupling of metabolic energy to membrane potential, thereby regulating many essential cell functions. Here, we demonstrate that a subunit of human KATP channel, KCNJ8/Kir6.1, is expressed preferentially in the human heart. Somatic cell-hybrid mapping and fluorescence in-situ hybridization (FISH) localize human KCNJ8 to the short arm of human chromosome 12, at 12p12. Partial characterization of the human Kir6. 1 gene demonstrates that there is one large intron in the coding region and at least two additional introns in the 5' untranslated region resulting in transcripts that have differential expression in human tissues examined. Our studies provide information on the complexity of the Kir6.1 transcript in the 5' UTR that may be useful for future investigations on the tissue-specific regulation and function of this KATP channel gene.
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Affiliation(s)
- N Erginel-Unaltuna
- Department of Cardiovascular Drug Discovery, Bristol-Myers Squibb Pharmaceutical Research Institute, Route 206, Provinceline Road, Princeton, NJ 08543-4000, USA
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12
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Abstract
BACKGROUND Mutations that map to the KvLQT1 gene on human chromosome 11 account for more than 50% of inherited long QT syndrome (LQTS). It has been discovered recently that the KvLQT1 and minK proteins functionally interact to generate a current with biophysical properties similar to I(Ks), the slowly activating delayed-rectifier cardiac potassium current. Since I(Ks) modulates the repolarization of cardiac action potentials it is reasonable to hypothesize that mutations in KvLQT1 reduce I(Ks), resulting in the prolongation of cardiac action potential duration. METHODS AND RESULTS We expressed LQTS-associated KvLQT1 mutants in Xenopus oocytes either individually or in combination with wild-type KvLQT1 or in combination with both wild-type KvLQT1 and minK. Substitutions of alanine with proline in the S2-S3 cytoplasmic loop (A177P) or threonine with isoleucine in the highly conserved signature sequence of the pore (T311I) yield inactive channels when expressed individually, whereas substitution of leucine with phenylalanine in the S5 transmembrane domain (L272F) yields a functional channel with reduced macroscopic conductance. However, all these mutants inhibit wild-type KvLQT1 currents in a dominant-negative fashion. CONCLUSIONS In LQTS-affected individuals these mutations would be predicted to result in a diminution of the cardiac I(Ks) current, subsequent prolongation of cardiac repolarization, and an increased risk of arrhythmias.
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Affiliation(s)
- F Y Shalaby
- Department of Cardiovascular Drug Discovery, Bristol-Myers Squibb Pharmaceutical Research Institute, Princeton, NJ 08543-4000, USA
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13
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Yang WP, Levesque PC, Little WA, Conder ML, Shalaby FY, Blanar MA. KvLQT1, a voltage-gated potassium channel responsible for human cardiac arrhythmias. Proc Natl Acad Sci U S A 1997; 94:4017-21. [PMID: 9108097 PMCID: PMC20560 DOI: 10.1073/pnas.94.8.4017] [Citation(s) in RCA: 164] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The clinical features of long QT syndrome result from episodic life-threatening cardiac arrhythmias, specifically the polymorphic ventricular tachycardia torsades de pointes. KVLQT1 has been established as the human chromosome 11-linked gene responsible for more than 50% of inherited long QT syndrome. Here we describe the cloning of a full-length KVLQT1 cDNA and its functional expression. KVLQT1 encodes a 676-amino acid polypeptide with structural characteristics similar to voltage-gated potassium channels. Expression of KvLQT1 in Xenopus oocytes and in human embryonic kidney cells elicits a rapidly activating, K+-selective outward current. The I(Kr)-specific blockers, E-4031 and dofetilide, do not inhibit KvLQT1, whereas clofilium, a class III antiarrhythmic agent with the propensity to induce torsades de pointes, substantially inhibits the current. Elevation of cAMP levels in oocytes nearly doubles the amplitude of KvLQT1 currents. Coexpression of minK with KvLQT1 results in a conductance with pharmacological and biophysical properties more similar to I(Ks) than other known delayed rectifier K+ currents in the heart.
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Affiliation(s)
- W P Yang
- Department of Cardiovascular Drug Discovery, Bristol-Myers Squibb Pharmaceutical Research Institute, Princeton, NJ 08543-4000, USA
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14
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Cross JC, Flannery ML, Blanar MA, Steingrimsson E, Jenkins NA, Copeland NG, Rutter WJ, Werb Z. Hxt encodes a basic helix-loop-helix transcription factor that regulates trophoblast cell development. Development 1995; 121:2513-23. [PMID: 7671815 DOI: 10.1242/dev.121.8.2513] [Citation(s) in RCA: 230] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Trophoblast cells are the first lineage to form in the mammalian conceptus and mediate the process of implantation. We report the cloning of a basic helix-loop-helix (bHLH) transcription factor gene, Hxt, that is expressed in early trophoblast and in differentiated giant cells. A separate gene, Hed, encodes a related protein that is expressed in maternal deciduum surrounding the implantation site. Overexpression of Hxt in mouse blastomeres directed their development into trophoblast cells in blastocysts. In addition, overexpression of Hxt induced the differentiation of rat trophoblast (Rcho-1) stem cells as assayed by changes in cell adhesion and by activation of the placental lactogen-I gene promoter, a trophoblast giant cell-specific gene. In contrast, the negative HLH regulator, Id-1, inhibited Rcho-1 differentiation and placental lactogen-I transcription. These data demonstrate a role for HLH factors in regulating trophoblast development and indicate a positive role for Hxt in promoting the formation of trophoblast giant cells.
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Affiliation(s)
- J C Cross
- Department of Anatomy, University of California, San Francisco 94143, USA
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15
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Steingrímsson E, Sawadogo M, Gilbert DJ, Zervos AS, Brent R, Blanar MA, Fisher DE, Copeland NG, Jenkins NA. Murine chromosomal location of five bHLH-Zip transcription factor genes. Genomics 1995; 28:179-83. [PMID: 8530024 DOI: 10.1006/geno.1995.1129] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The genes for the bHLH-Zip transcription factors Tfap4, Mxi1, Tcfeb, Usf1, and Usf2 have been mapped in mouse by interspecific backcross analysis. Mxi1, Usf1, and Usf2 have been mapped previously by in situ hybridization, but their positions on the meiotic linkage map had not been determined. The other two genes have not previously been mapped in mouse. These transcription factors belong to a growing family of transcriptional regulators, some of which are known to form a complex network of interacting proteins that control cell proliferation and apoptosis. As expected, based on mapping studies of other bHLH-Zip genes, these loci were well distributed among mouse chromosomes. In addition, some of the probes used in this study detected multiple, independently segregating loci, suggesting the possible existence of additional family members or species-specific pseudogenes.
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Affiliation(s)
- E Steingrímsson
- Mammalian Genetics Laboratory, ABL-Basic Research Program, NCI-Frederick Cancer Research and Development Center, Maryland 21702, USA
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16
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Blanar MA, Crossley PH, Peters KG, Steingrímsson E, Copeland NG, Jenkins NA, Martin GR, Rutter WJ. Meso1, a basic-helix-loop-helix protein involved in mammalian presomitic mesoderm development. Proc Natl Acad Sci U S A 1995; 92:5870-4. [PMID: 7597044 PMCID: PMC41603 DOI: 10.1073/pnas.92.13.5870] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
To identify genes involved in the regulation of early mammalian development, we have developed a dominant-negative mutant basic-helix-loop-helix (bHLH) protein probe for interaction cloning and have isolated a member of the bHLH family of transcription factors, Meso1. Meso1-E2A heterodimers are capable of binding to oligonucleotide probes that contain a bHLH DNA recognition motif. In mouse embryos, Meso1 is expressed prior to MyoD1 family members. Meso1 expression is first detected at the neural plate stage of development in the paraxial mesoderm of the head and in presomitic mesodermal cells prior to their condensation into somites. Our findings suggest that Meso1 may be a key regulatory gene involved in the early events of vertebrate mesoderm differentiation.
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Affiliation(s)
- M A Blanar
- Hormone Research Institute, University of California, San Francisco 94143, USA
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17
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Quertermous EE, Hidai H, Blanar MA, Quertermous T. Cloning and characterization of a basic helix-loop-helix protein expressed in early mesoderm and the developing somites. Proc Natl Acad Sci U S A 1994; 91:7066-70. [PMID: 8041747 PMCID: PMC44339 DOI: 10.1073/pnas.91.15.7066] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Basic helix-loop-helix (bHLH) heterodimer protein complexes regulate transcription of genes during the processes of differentiation and development. To study the molecular basis of early mesodermal differentiation, we sought to identify bHLH proteins from cells of mesodermal origin. By using an interaction cloning strategy with a radiolabled recombinant bHLH protein, E12, a clone encoding a potential heterodimer partner was isolated from an endothelial cell library. This gene (bHLH-EC2) is most homologous to Twist but shares similarity within the bHLH domain with TAL1 and other members of this family. bHLH-EC2 is expressed in cultured endothelial cells and in embryonic stem cell, erythroleukemia, and muscle cell lines in a differentiation-dependent manner. In situ hybridization studies of mouse embryos reveal that bHLH-EC2 is expressed throughout the primitive mesoderm as early as 7.5 days postcoitum. Expression then becomes restricted to the paraxial mesoderm and to the dermamyotome of the developing somite. Expression of bHLH-EC2 in cells destined to become myoblasts thus predates expression of myogenic bHLH factors. bHLH-EC2 is expressed in early endothelial and hematopoietic cells in vivo, as shown by RNA studies of embryonic yolk sac and cultured cells derived from yolk sac explants. These findings suggest that bHLH-EC2 plays a role in the development of multiple cell types derived from the primitive mesoderm.
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Affiliation(s)
- E E Quertermous
- Department of Medicine, Vanderbilt University Medical School, Nashville, TN 37232
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18
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Gutsch DE, Holley-Guthrie EA, Zhang Q, Stein B, Blanar MA, Baldwin AS, Kenney SC. The bZIP transactivator of Epstein-Barr virus, BZLF1, functionally and physically interacts with the p65 subunit of NF-kappa B. Mol Cell Biol 1994; 14:1939-48. [PMID: 8114725 PMCID: PMC358552 DOI: 10.1128/mcb.14.3.1939-1948.1994] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The Epstein-Barr virus (EBV) BZLF1 (Z) immediate-early transactivator initiates the switch between latent and productive infection in B cells. The Z protein, which has homology to the basic leucine zipper protein c-Fos, transactivates the promoters of several replicative cycle proteins. Transactivation efficiency of the EBV BMRF1 promoter by Z is cell type dependent. In B cells, in which EBV typically exists in a latent form, Z activates the BMRF1 promoter inefficiently. We have discovered that the p65 component of the cellular factor NF-kappa B inhibits transactivation of several EBV promoters by Z. Furthermore, the inhibitor of NF-kappa B, I kappa B alpha, can augment Z-induced transactivation in the B-cell line Raji. Using glutathione S-transferase fusion proteins and coimmunoprecipitation studies, we demonstrate a direct interaction between Z and p65. This physical interaction, which requires the dimerization domain of Z and the Rel homology domain of p65, can be demonstrated both in vitro and in vivo. Inhibition of Z transactivation function by NF-kappa B p65, or possibly by other Rel family proteins, may contribute to the inefficiency of Z transactivator function in B cells and may be a mechanism of maintaining B-cell-specific viral latency.
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Affiliation(s)
- D E Gutsch
- UNC Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill 27599-7295
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19
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Abstract
The NF-kappa B-p50 polypeptide, a member of the Rel family of transcription factors, was produced as a fusion protein containing amino-terminal peptide additions that facilitate purification and detection with a monoclonal antibody and specific radiolabeling by phosphorylation in vitro. The 32P-labeled NK-kappa B-p50 fusion polypeptide was used as the probe in Western blotting experiments and in screenings of a bacteriophage expression library to isolate cDNAs encoding interacting protein domains. As expected, cDNAs encoding proteins of the Rel family were identified. Surprisingly, the 32P-labeled NF-kappa B protein also specifically bound to proteins encoded by cDNAs for the human NF-IL6 transcription factor. The NF-kappa B-p50 and NF-IL6 proteins directly interact, and the Rel homology domain and leucine-zipper motif, respectively, are important for this interaction. Since induction of the NF-kappa B and NF-IL6 factors are important events in immune and acute-phase responses, this interaction could permit coregulation of genes.
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Affiliation(s)
- K P LeClair
- Center for Cancer Research, Massachusetts Institute of Technology, Cambridge 02139
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20
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Kaelin WG, Krek W, Sellers WR, DeCaprio JA, Ajchenbaum F, Fuchs CS, Chittenden T, Li Y, Farnham PJ, Blanar MA. Expression cloning of a cDNA encoding a retinoblastoma-binding protein with E2F-like properties. Cell 1992; 70:351-64. [PMID: 1638635 DOI: 10.1016/0092-8674(92)90108-o] [Citation(s) in RCA: 730] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
An expression vector was modified to permit the rapid synthesis of purified, 32P-labeled, glutathione S-transferase (GST)-retinoblastoma (RB) fusion proteins. The products were used to screen lambda gt11 expression libraries, from which we cloned a cDNA encoding a polypeptide (RBAP-1) capable of binding directly to a putative functional domain (the pocket) of the retinoblastoma gene product (RB). The RB "pocket" is known to bind, directly or indirectly, to the cellular transcription factor, E2F, implicated in cell growth control. We have found that RBAP-1 copurifies with E2F, interacts specifically with the adenovirus E4 ORF 6/7 protein, binds specifically and directly to a known E2F DNA recognition sequence, and contains a functional tranasactivation domain. Therefore, RBAP-1 is a species of E2F and can bind specifically to the RB pocket.
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Affiliation(s)
- W G Kaelin
- Dana Farber Cancer Institute, Boston, Massachusetts
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21
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Abstract
A facile method for isolating genes that encode interacting proteins has been developed with a polypeptide probe that contains an amino-terminal extension with recognition sites for a monoclonal antibody, a specific endopeptidase, and a site-specific protein kinase. This probe, containing the basic region-leucine zipper dimerization motif of c-Fos, was used to screen a complementary DNA library. A complementary DNA that encoded a member of the basic-helix-loop-helix-zipper (bHLH-Zip) family of proteins was isolated. The complementary DNA-encoded polypeptide FIP (Fos interacting protein) bound to oligonucleotide probes that contained DNA binding motifs for other HLH proteins. When cotransfected with c-Fos, FIP stimulated transcription of an AP-1-responsive promoter.
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Affiliation(s)
- M A Blanar
- Hormone Research Institute, University of California, San Francisco 94143
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22
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German MS, Blanar MA, Nelson C, Moss LG, Rutter WJ. Two related helix-loop-helix proteins participate in separate cell-specific complexes that bind the insulin enhancer. Mol Endocrinol 1991; 5:292-9. [PMID: 1710033 DOI: 10.1210/mend-5-2-292] [Citation(s) in RCA: 129] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Cell-specific expression of the insulin gene is dependent on a conserved 8-basepair sequence, GCCATCTG, present in two copies in the 5' flanking DNA of the rat insulin 1 gene (Nir and Far elements). A protein factor with well characterized binding affinities binds to this sequence and is unique to the nuclei of insulin-producing cells. Using the Nir element as a probe to screen a hamster insulinoma cDNA expression library, we cloned two cDNA inserts that encode two related helix-loop-helix DNA-binding proteins: Syrian hamster Pan-1 (shPan-1) and Syrian hamster Pan-2 (shPan-2). These clones have minimal differences from the previously reported human E47/E12 and rat PAN (rPan) DNA-binding proteins. In vitro translated protein products of both clones bound the insulin gene promoter Nir and far elements as well as the E2 elements of the mu heavy chain and kappa light chain immunoglobulin genes. Treating insulinoma cell nuclear extract with antiserum selectively directed to each of the two shPan proteins demonstrated the presence of each form of shPan in separate DNA-binding complexes, which together form the previously described, cell-specific, Nir element-binding complex. We conclude that shPan-1 and shPan-2 are the hamster homologs of the ubiquitous E47/E12 and rPan proteins, but form parts of distinct DNA-binding complexes apparently found only in the nuclei of insulin-producing cells.
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Affiliation(s)
- M S German
- Hormone Research Institute, University of California, San Francisco 94143-0534
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23
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Abstract
Transcription of class I genes of the major histocompatibility complex (MHC) can be induced by interferons. Treatment of HeLa cells with interferon-gamma induces a DNA-binding factor, IBP-1, specific for a site within the interferon response sequence (IRS) of the H-2Kb promoter. The mol. wt of IBP-1, as estimated by photoactivated protein-DNA crosslinking analysis, is approximately 59 kd. Point-mutation of this binding site abolishes IBP-1 interaction and the ability of the MHC promoter to respond to interferon. Induction of this binding activity is rapid and closely parallels the previously reported time course of transcriptional activation of endogenous MHC class I genes. Treatment of cells with cycloheximide, a protein synthesis inhibitor, blocked the induction of the DNA-binding activity. An oligonucleotide derived from the virus- and double-stranded RNA-inducible promoter of the interferon-beta 1 gene is able to bind IBP-1. Sequences similar to the IBP-1 binding site are found upstream of many interferon-responsive genes.
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Affiliation(s)
- M A Blanar
- Biogen Research Corporation, Cambridge, MA 02142
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24
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Blanar MA, Burkly LC, Flavell RA. NF-kappa B binds within a region required for B-cell-specific expression of major histocompatibility complex class II gene E alpha d. Mol Cell Biol 1989; 9:844-6. [PMID: 2496303 PMCID: PMC362665 DOI: 10.1128/mcb.9.2.844-846.1989] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
A region upstream of the murine major histocompatibility complex gene, E alpha d, has been shown previously to be required for B-cell expression. Binding of the B-cell-specific factor, NF-kappa B, to a site within this region is indistinguishable from that observed with the kappa enhancer binding site. NF-kappa B may be responsible for E alpha d B-cell expression.
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Affiliation(s)
- M A Blanar
- Biogen Research Corporation, Cambridge, Massachusetts 02142
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25
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Böttger EC, Blanar MA, Flavell RA. Cycloheximide, an inhibitor of protein synthesis, prevents gamma-interferon-induced expression of class II mRNA in a macrophage cell line. Immunogenetics 1988; 28:215-20. [PMID: 3138175 DOI: 10.1007/bf00345497] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
To characterize the mechanisms by which interferon gamma (IFN-gamma) upregulates major histocompatibility complex class II mRNA levels in mouse macrophages, we studied the effect of IFN-gamma on the transcription rate of class II genes and investigated the requirement for ongoing protein synthesis for the induction of class II mRNA expression. Nuclear run-off assays demonstrate that IFN-gamma induces class II mRNA at the transcriptional level. Treatment with cycloheximide, an inhibitor of protein synthesis, prevented the IFN-gamma-mediated accumulation of E alpha mRNA in the mouse macrophage cell line P388 D.1, indicating that induction of E alpha mRNA in P388 D.1 cells requires de novo synthesis of a protein intermediate. Our studies suggest that this putative protein factor is labile and required throughout the induction period.
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26
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Blanar MA, Boettger EC, Flavell RA. Transcriptional activation of HLA-DR alpha by interferon gamma requires a trans-acting protein. Proc Natl Acad Sci U S A 1988; 85:4672-6. [PMID: 3133656 PMCID: PMC280497 DOI: 10.1073/pnas.85.13.4672] [Citation(s) in RCA: 87] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Stimulation of the human epithelial-like cell line, HeLa, with interferon gamma (IFN-gamma) induces steady-state levels of HLA-DR alpha mRNA. Using a sensitive RNase-mapping procedure, we detect induced HLA-DR alpha mRNA as early as 8 hr after IFN-gamma treatment; maximal accumulation occurs by 48 hr. Treatment with the protein synthesis inhibitor, cycloheximide, abolishes the IFN-gamma-induced accumulation of HLA-DR alpha mRNA, indicating that de novo synthesis of a trans-acting protein factor is required for induction of this major histocompatibility complex class II gene. Nuclear run-off transcription assays revealed that IFN-gamma acts by directly stimulating the transcription rate of HLA-DR alpha. Similarly, IFN-gamma increased the transcription rate of the class I HLA-A2-encoding gene as well as that of the human invariant chain gene. IFN-gamma-induced transcription of HLA-DR alpha and of the invariant chain gene was blocked by treatment with cycloheximide, but IFN-gamma-induced transcription of HLA-A2 was unaffected. Our findings show that transcriptional induction of HLA-DR alpha and the invariant chain gene by IFN-gamma requires the action of an unidentified trans-acting protein.
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Affiliation(s)
- M A Blanar
- Biogen Research Corporation, Cambridge, MA 02142
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27
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Abstract
We analyzed the nucleotide sequence of a 1.325-kilobase region of wild-type Escherichia coli containing a functional recF gene and six Tn3 mutations that inactivate recF. The analysis shows a potentially translatable reading frame of 1071 nucleotides, which is interrupted by all six insertions. A protein of 40.5 kilodaltons would result from translation of the open reading frame, and a radioactive band of protein of an apparent molecular weight of approximately 40 kilodaltons was seen by the maxicell method using a recF+ plasmid. Putative truncated peptides were seen when two recF::Tn3 mutant plasmids were used. Differential expression of dnaN and recF from a common promoter was noted. recF332::Tn3 was transferred to the chromosome where, in hemizygous condition, it produced UV sensitivity indistinguishable from that produced by two presumed recF point mutations.
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28
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Clark AJ, Sandler SJ, Willis DK, Chu CC, Blanar MA, Lovett ST. Genes of the RecE and RecF pathways of conjugational recombination in Escherichia coli. Cold Spring Harb Symp Quant Biol 1984; 49:453-62. [PMID: 6397300 DOI: 10.1101/sqb.1984.049.01.051] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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29
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Blanar MA, Kneller D, Clark AJ, Karu AE, Cohen FE, Langridge R, Kuntz ID. A model for the core structure of the Escherichia coli RecA protein. Cold Spring Harb Symp Quant Biol 1984; 49:507-11. [PMID: 6397305 DOI: 10.1101/sqb.1984.049.01.057] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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