301
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Dunn SE, Simard AR, Bassel-Duby R, Williams RS, Michel RN. Nerve activity-dependent modulation of calcineurin signaling in adult fast and slow skeletal muscle fibers. J Biol Chem 2001; 276:45243-54. [PMID: 11555650 DOI: 10.1074/jbc.m105445200] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
This study tested the hypothesis that calcineurin signaling is modulated in skeletal muscle cells by fluctuations in nerve-mediated activity. We show that dephosphorylation of NFATc1, MEF2A, and MEF2D transcription factors by calcineurin in all muscle types is dependent on nerve activity and positively correlated with muscle usage under normal weightbearing conditions. With increased nerve-mediated activity, calcineurin dephosphorylation of these targets was found to be potentiated in a way that paralleled the higher muscle activation profiles associated with functional overload or nerve electrical stimulation conditions. We also establish that muscle activity must be sustained above native levels for calcineurin-dependent dephosphorylation of MEF2A and MEF2D to be transduced into an increase in MEF2 transcriptional function, suggesting that calcineurin cooperates with other activity-linked events to signal via these proteins. Finally, examination of individual fiber responses to overload and nerve electrical stimulation revealed that calcineurin-MEF2 signaling occurs in all fiber types but most readily in fibers that are normally least active (i.e. those expressing IIx and IIb myosin heavy chain (MHC)), suggesting that signaling via this phosphatase is also dependent upon the activation history of the muscle cell.
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Affiliation(s)
- S E Dunn
- Neuromuscular Research Laboratory, Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario P3E 2C6, Canada
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302
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Wu H, Rothermel B, Kanatous S, Rosenberg P, Naya FJ, Shelton JM, Hutcheson KA, DiMaio J, Olson EN, Bassel-Duby R, Williams R. Activation of MEF2 by muscle activity is mediated through a calcineurin-dependent pathway. EMBO J 2001; 20:6414-23. [PMID: 11707412 PMCID: PMC125719 DOI: 10.1093/emboj/20.22.6414] [Citation(s) in RCA: 294] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Gene expression in skeletal muscles of adult vertebrates is altered profoundly by changing patterns of contractile work. Here we observed that the functional activity of MEF2 transcription factors is stimulated by sustained periods of endurance exercise or motor nerve pacing, as assessed by expression in trans genic mice of a MEF2-dependent reporter gene (desMEF2-lacZ). This response is accompanied by transformation of specialized myofiber subtypes, and is blocked either by cyclosporin A, a specific chemical inhibitor of calcineurin, or by forced expression of the endogenous calcineurin inhibitory protein, myocyte-enriched calcineurin interacting protein 1. Calcineurin removes phosphate groups from MEF2, and augments the potency of the transcriptional activation domain of MEF2 fused to a heterologous DNA binding domain. Across a broad range, the enzymatic activity of calcineurin correlates directly with expression of endogenous genes that are transcriptionally activated by muscle contractions. These results delineate a molecular pathway in which calcineurin and MEF2 participate in the adaptive mechanisms by which skeletal myofibers acquire specialized contractile and metabolic properties as a function of changing patterns of muscle contraction.
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MESH Headings
- Animals
- Calcineurin/metabolism
- Cyclosporine/pharmacology
- DNA, Complementary/metabolism
- DNA-Binding Proteins/metabolism
- Dose-Response Relationship, Drug
- Enzyme Activation
- Enzyme Inhibitors/pharmacology
- Genes, Reporter
- Immunoblotting
- Kinetics
- MEF2 Transcription Factors
- Mice
- Mice, Inbred C57BL
- Mice, Transgenic
- Models, Biological
- Muscle Contraction
- Muscle, Skeletal/metabolism
- Myogenic Regulatory Factors
- Myoglobin/biosynthesis
- Physical Conditioning, Animal
- Physical Exertion
- Plasmids/metabolism
- Precipitin Tests
- Protein Binding
- Protein Structure, Tertiary
- RNA/metabolism
- RNA, Messenger/metabolism
- Time Factors
- Transcription Factors/metabolism
- Transcription, Genetic
- Transcriptional Activation
- Transfection
- beta-Galactosidase/metabolism
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Affiliation(s)
- Hai Wu
- Departments of Internal Medicine, Molecular Biology and Surgery, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA Corresponding author e-mail:
| | - Beverly Rothermel
- Departments of Internal Medicine, Molecular Biology and Surgery, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA Corresponding author e-mail:
| | - Shane Kanatous
- Departments of Internal Medicine, Molecular Biology and Surgery, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA Corresponding author e-mail:
| | - Paul Rosenberg
- Departments of Internal Medicine, Molecular Biology and Surgery, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA Corresponding author e-mail:
| | - Francisco J. Naya
- Departments of Internal Medicine, Molecular Biology and Surgery, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA Corresponding author e-mail:
| | - John M. Shelton
- Departments of Internal Medicine, Molecular Biology and Surgery, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA Corresponding author e-mail:
| | - Kelley A. Hutcheson
- Departments of Internal Medicine, Molecular Biology and Surgery, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA Corresponding author e-mail:
| | - J.Michael DiMaio
- Departments of Internal Medicine, Molecular Biology and Surgery, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA Corresponding author e-mail:
| | - Eric N. Olson
- Departments of Internal Medicine, Molecular Biology and Surgery, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA Corresponding author e-mail:
| | - Rhonda Bassel-Duby
- Departments of Internal Medicine, Molecular Biology and Surgery, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA Corresponding author e-mail:
| | - R.Sanders Williams
- Departments of Internal Medicine, Molecular Biology and Surgery, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA Corresponding author e-mail:
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303
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Ermak G, Morgan TE, Davies KJ. Chronic overexpression of the calcineurin inhibitory gene DSCR1 (Adapt78) is associated with Alzheimer's disease. J Biol Chem 2001; 276:38787-94. [PMID: 11483593 DOI: 10.1074/jbc.m102829200] [Citation(s) in RCA: 169] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The DSCR1 (Adapt78) gene was independently discovered as a resident of the "Down syndrome candidate region"and as an "adaptive response"shock or stress gene that is transiently induced during oxidative stress. Recently the DSCR1 (Adapt78) gene product was discovered to be an inhibitor of the serine/threonine phosphatase, calcineurin, and its signaling pathways. We hypothesized that DSCR1 (Adapt78) might also be involved in the development of Alzheimer's disease. To address this question we first studied DSCR1 (Adapt78) in multiple human tissues and found significant expression in brain, spinal cord, kidney, liver, mammary gland, skeletal muscle, and heart. Within the brain DSCR1 (Adapt78) is predominantly expressed in neurons within the cerebral cortex, hippocampus, substantia nigra, thalamus, and medulla oblongata. When we compared DSCR1 (Adapt78) mRNA expression in post-mortem brain samples from Alzheimer's disease patients and individuals who had died with no Alzheimer's diagnosis, we found that DSCR1 (Adapt78) mRNA levels were about twice as high in age-matched Alzheimer's patients as in controls. DSCR1 (Adapt78) mRNA levels were actually three times higher in patients with extensive neurofibrillary tangles (a hallmark of Alzheimer's disease) than in controls. In comparison, post-mortem brain samples from Down syndrome patients (who suffer Alzheimer's symptoms) also exhibited DSCR1 (Adapt78) mRNA levels two to three times higher than controls. Using a cell culture model we discovered that the amyloid beta(1-42) peptide, which is a major component of senile plaques in Alzheimer's, can directly induce increased expression of DSCR1 (Adapt78). Our findings associate DSCR1 (Adapt78) with such major hallmarks of Alzheimer's disease as amyloid protein, senile plaques, and neurofibrillary tangles.
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Affiliation(s)
- G Ermak
- Ethel Percy Andrus Gerontology Center and Division of Molecular Biology, The University of Southern California, Los Angeles, California 90089-0191, USA
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304
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Abstract
NFATc proteins transduce Ca(2+) signals to the nucleus and then pair with other proteins on DNA to generate NFAT complexes that activate transcription in response to both electrical and tyrosine kinase signaling. The four NFATc genes arose at the origin of vertebrates, implying that they have evolved for the development of vertebrate-specific functions, such as a complex nervous system, a recombinational immune system, and a vascular system with a complex heart. These speculations are borne out by studies of mice with null mutations in the different family members.
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Affiliation(s)
- I A Graef
- Department of Developmental Biology, Stanford University Medical School, Stanford, CA 94305, USA
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305
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Affiliation(s)
- R T Lee
- Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
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306
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Aronow BJ, Toyokawa T, Canning A, Haghighi K, Delling U, Kranias E, Molkentin JD, Dorn GW. Divergent transcriptional responses to independent genetic causes of cardiac hypertrophy. Physiol Genomics 2001; 6:19-28. [PMID: 11395543 DOI: 10.1152/physiolgenomics.2001.6.1.19] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
To define molecular mechanisms of cardiac hypertrophy, genes whose expression was perturbed by any of four different transgenic mouse hypertrophy models [protein kinase C-epsilon activation peptide (PsiepsilonRACK), calsequestrin (CSQ), calcineurin (CN), and Galpha(q)] were compared by DNA microarray analyses using the approximately 8,800 genes present on the Incyte mouse GEM1. The total numbers of regulated genes (tens to hundreds) correlated with phenotypic severity of the model (Galpha(q) > CN > CSQ > PsiepsilonRACK), but demonstrated that no single gene was consistently upregulated. Of the three models exhibiting pathological hypertrophy, only atrial natriuretic peptide was consistently upregulated, suggesting that transcriptional alterations are highly specific to individual genetic causes of hypertrophy. However, hierarchical-tree and K-means clustering analyses revealed that subsets of the upregulated genes did exhibit coordinate regulatory patterns that were unique or overlapping across the different hypertrophy models. One striking set consisted of apoptotic genes uniquely regulated in the apoptosis-prone Galpha(q) model. Thus, rather than identifying a single common hypertrophic cardiomyopathy gene program, these data suggest that extensive groups of genes may be useful for the prediction of specific underlying genetic determinants and condition-specific therapeutic approaches.
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Affiliation(s)
- B J Aronow
- Department of Developmental Biology, Children's Hospital Research Center, Cincinnati, OH 45229, USA
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307
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Graef IA, Gastier JM, Francke U, Crabtree GR. Evolutionary relationships among Rel domains indicate functional diversification by recombination. Proc Natl Acad Sci U S A 2001; 98:5740-5. [PMID: 11344309 PMCID: PMC33283 DOI: 10.1073/pnas.101602398] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/20/2000] [Indexed: 02/07/2023] Open
Abstract
The recent sequencing of several complete genomes has made it possible to track the evolution of large gene families by their genomic structure. Following the large-scale association of exons encoding domains with well defined functions in invertebrates could be useful in predicting the function of complex multidomain proteins in mammals produced by accretion of domains. With this objective, we have determined the genomic structure of the 14 genes in invertebrates and vertebrates that contain rel domains. The sequence encoding the rel domain is defined by intronic boundaries and has been recombined with at least three structurally and functionally distinct genomic sequences to generate coding sequences for: (i) the rel/Dorsal/NFkappaB proteins that are retained in the cytoplasm by IkB-like proteins; (ii) the NFATc proteins that sense calcium signals and undergo cytoplasmic-to-nuclear translocation in response to dephosphorylation by calcineurin; and (iii) the TonEBP tonicity-responsive proteins. Remarkably, a single exon in each NFATc family member encodes the entire Ca(2+)/calcineurin sensing region, including nuclear import/export, calcineurin-binding, and substrate regions. The Rel/Dorsal proteins and the TonEBP proteins are present in Drosophila but not Caenorhabditis elegans. On the other hand, the calcium-responsive NFATc proteins are present only in vertebrates, suggesting that the NFATc family is dedicated to functions specific to vertebrates such as a recombinational immune response, cardiovascular development, and vertebrate-specific aspects of the development and function of the nervous system.
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Affiliation(s)
- I A Graef
- Department of Genetics, Howard Hughes Medical Institute, Stanford University Medical School, Stanford, CA 94305-5323, USA
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308
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Siddiq A, Miyazaki T, Takagishi Y, Kanou Y, Hayasaka S, Inouye M, Seo H, Murata Y. Expression of ZAKI-4 messenger ribonucleic acid in the brain during rat development and the effect of hypothyroidism. Endocrinology 2001; 142:1752-9. [PMID: 11316738 DOI: 10.1210/endo.142.5.8156] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
We identified ZAKI-4 (also designated as DSCR1L1) as a thyroid hormone responsive gene in cultured human skin fibroblasts. Recently it has been reported that ZAKI-4 belongs to an evolutionary conserved family of proteins that function as calcineurin inhibitor. In human, ZAKI-4 and calcineurin are highly expressed in brain, where thyroid hormones play essential roles in the development during fetal and neonatal periods. In the present study, we examined the temporal and spatial expression patterns of ZAKI-4 messenger RNA (mRNA) in control and hypothyroid rat brains. Northern blot analysis revealed that ZAKI-4 mRNA was detected in both cerebral cortex and cerebellum as early as embryonic day (E)18. In the cerebral cortex, the expression level gradually increased with age, reaching a plateau at postnatal day (P)7 and remained constant thereafter until P30. A similar pattern of increase with age was also observed in hypothyroid rats; however, the magnitude of the increase was significantly reduced. In control rats, the fold increase in ZAKI-4 mRNA level from E18 to P17 was 10.8; whereas in hypothyroid rats, it was 7.4. In cerebellum the expression level did not change with age or by thyroid status. In situ hybridization revealed that ZAKI-4 mRNA is widely expressed in neurons throughout the brain. It is noteworthy that the expression in the neurons of layer VI of the cerebral cortex was more evident in control rats than that in hypothyroid rats from P17 to P30. Though not influenced by hypothyroidism, there were several regions of the brain in which ZAKI-4 mRNA was strongly expressed. These regions were the mitral cell layer of the olfactory bulb, the substantia nigra, and the hippocampus, where calcineurin is also abundantly expressed. Therefore, it may be hypothesized that ZAKI-4 plays an important role in the development and function of the brain by modulating calcineurin function; and decrease in ZAKI-4 mRNA expression in the specific brain areas may explain, in some parts, the mechanism of abnormal brain development by hypothyroidism.
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Affiliation(s)
- A Siddiq
- Department of Teratology and Genetics, Division of Molecular and Cellular Adaptation, Research Institute of Environmental Medicine, Nagoya University, Nagoya 464-8601, Japan
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309
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Rothermel BA, McKinsey TA, Vega RB, Nicol RL, Mammen P, Yang J, Antos CL, Shelton JM, Bassel-Duby R, Olson EN, Williams RS. Myocyte-enriched calcineurin-interacting protein, MCIP1, inhibits cardiac hypertrophy in vivo. Proc Natl Acad Sci U S A 2001; 98:3328-33. [PMID: 11248078 PMCID: PMC30653 DOI: 10.1073/pnas.041614798] [Citation(s) in RCA: 242] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Signaling events controlled by calcineurin promote cardiac hypertrophy, but the degree to which such pathways are required to transduce the effects of various hypertrophic stimuli remains uncertain. In particular, the administration of immunosuppressive drugs that inhibit calcineurin has inconsistent effects in blocking cardiac hypertrophy in various animal models. As an alternative approach to inhibiting calcineurin in the hearts of intact animals, transgenic mice were engineered to overexpress a human cDNA encoding the calcineurin-binding protein, myocyte-enriched calcineurin-interacting protein-1 (hMCIP1) under control of the cardiac-specific, alpha-myosin heavy chain promoter (alpha-MHC). In unstressed mice, forced expression of hMCIP1 resulted in a 5-10% decline in cardiac mass relative to wild-type littermates, but otherwise produced no apparent structural or functional abnormalities. However, cardiac-specific expression of hMCIP1 inhibited cardiac hypertrophy, reinduction of fetal gene expression, and progression to dilated cardiomyopathy that otherwise result from expression of a constitutively active form of calcineurin. Expression of the hMCIP1 transgene also inhibited hypertrophic responses to beta-adrenergic receptor stimulation or exercise training. These results demonstrate that levels of hMCIP1 producing no apparent deleterious effects in cells of the normal heart are sufficient to inhibit several forms of cardiac hypertrophy, and suggest an important role for calcineurin signaling in diverse forms of cardiac hypertrophy. The future development of measures to increase expression or activity of MCIP proteins selectively within the heart may have clinical value for prevention of heart failure.
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Affiliation(s)
- B A Rothermel
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
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310
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Leinwand LA. Calcineurin inhibition and cardiac hypertrophy: a matter of balance. Proc Natl Acad Sci U S A 2001; 98:2947-9. [PMID: 11248009 PMCID: PMC33335 DOI: 10.1073/pnas.051033698] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- L A Leinwand
- Department of Molecular, Cellular, and Developmental Biology, Porter Addition, Room A3B40, University of Colorado, Boulder, CO 80309-0347, USA.
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311
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De Windt LJ, Lim HW, Bueno OF, Liang Q, Delling U, Braz JC, Glascock BJ, Kimball TF, del Monte F, Hajjar RJ, Molkentin JD. Targeted inhibition of calcineurin attenuates cardiac hypertrophy in vivo. Proc Natl Acad Sci U S A 2001; 98:3322-7. [PMID: 11248077 PMCID: PMC30652 DOI: 10.1073/pnas.031371998] [Citation(s) in RCA: 156] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2000] [Indexed: 01/12/2023] Open
Abstract
The Ca(2+)-calmodulin-activated Ser/Thr protein phosphatase calcineurin and the downstream transcriptional effectors of calcineurin, nuclear factor of activated T cells, have been implicated in the hypertrophic response of the myocardium. Recently, the calcineurin inhibitory agents cyclosporine A and FK506 have been extensively used to evaluate the importance of this signaling pathway in rodent models of cardiac hypertrophy. However, pharmacologic approaches have rendered equivocal results necessitating more specific or genetic-based inhibitory strategies. In this regard, we have generated Tg mice expressing the calcineurin inhibitory domains of Cain/Cabin-1 and A-kinase anchoring protein 79 specifically in the heart. DeltaCain and DeltaA-kinase-anchoring protein Tg mice demonstrated reduced cardiac calcineurin activity and reduced hypertrophy in response to catecholamine infusion or pressure overload. In a second approach, adenoviral-mediated gene transfer of DeltaCain was performed in the adult rat myocardium to evaluate the effectiveness of an acute intervention and any potential species dependency. DeltaCain adenoviral gene transfer inhibited cardiac calcineurin activity and reduced hypertrophy in response to pressure overload without reducing aortic pressure. These results provide genetic evidence implicating calcineurin as an important mediator of the cardiac hypertrophic response in vivo.
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Affiliation(s)
- L J De Windt
- Divisions of Molecular Cardiovascular Biology and Cardiology, Department of Pediatrics, Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, OH 45229, USA
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312
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Casas C, Martínez S, Pritchard MA, Fuentes JJ, Nadal M, Guimerà J, Arbonés M, Flórez J, Soriano E, Estivill X, Alcántara S. Dscr1, a novel endogenous inhibitor of calcineurin signaling, is expressed in the primitive ventricle of the heart and during neurogenesis. Mech Dev 2001; 101:289-92. [PMID: 11231093 DOI: 10.1016/s0925-4773(00)00583-9] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We have demonstrated that DSCR1 acts as a negative regulator of calcineurin-mediated signaling and that its transcript is overexpressed in the Down syndrome (DS) fetal brain. To evaluate the possible involvement of DSCR1 in DS, we have cloned the mouse gene and analyzed its expression pattern in the central nervous system (CNS). Early expression of Dscr1 is detected mainly in the heart tube and in the CNS in rhombomere 4 and the pretectum. From embryonic day 14.5 onwards, Dscr1 is widely distributed in the CNS but becomes more restricted as the brain matures. We confirmed its neuronal expression pattern in the adult, preferentially in Purkinje and pyramidal cells, by double labeling with glial fibrillary acidic protein. We also show that although Dscr1 is present in trisomy in the Ts65Dn mouse, the adult brain expression pattern is not significantly altered. This expression pattern indicated that Dscr1 is a developmentally regulated gene involved in neurogenesis and cardiogenesis and suggests that it may contribute to the alterations observed in these organ systems in DS patients.
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Affiliation(s)
- C Casas
- Down Syndrome Research Group, Medical and Molecular Genetics Center - IRO, Avia. de Castelldefels, km. 2.7, L'Hospitalet de Llobregat, 08907, Barcelona, Spain
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313
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Cruz M, Fox DS, Heitman J. Calcineurin is required for hyphal elongation during mating and haploid fruiting in Cryptococcus neoformans. EMBO J 2001; 20:1020-32. [PMID: 11230126 PMCID: PMC145507 DOI: 10.1093/emboj/20.5.1020] [Citation(s) in RCA: 121] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2000] [Revised: 12/04/2000] [Accepted: 01/17/2001] [Indexed: 11/13/2022] Open
Abstract
Cryptococcus neoformans is a fungal pathogen that causes meningitis in immunocompromised patients. Its growth is sensitive to the immunosuppressants FK506 and cyclosporin, which inhibit the Ca2+- calmodulin-activated protein phosphatase calcineurin. Calcineurin is required for growth at 37 degrees C and virulence of C.neoformans. We found that calcineurin is also required for mating. FK506 blocks mating of C.neoformans via FKBP12-dependent inhibition of calcineurin, and mutants lacking calcineurin are bilaterally sterile. Calcineurin is not essential for the initial fusion event, but is required for hyphal elongation and survival of the heterokaryon produced by cell fusion. It is also required for hyphal elongation in diploid strains and during asexual haploid fruiting of MATalpha cells in response to nitrogen limitation. Because mating and haploid fruiting produce infectious basidiospores, our studies suggest a second link between calcineurin and virulence of C.neoformans. Calcine urin regulates filamentation and 37 degrees C growth via distinct pathways. Together with studies revealing that calcineurin mediates neurite extension and neutrophil migration in mammals, our findings indicate that calcineurin plays a conserved role in the control of cell morphology.
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Affiliation(s)
- M.Cristina Cruz
- Departments of
Genetics, Pharmacology and Cancer Biology, Microbiology and Medicine, The Howard Hughes Medical Institute, Duke University Medical Center, Durham, NC 27710, USA Corresponding author e-mail:
| | - Deborah S. Fox
- Departments of
Genetics, Pharmacology and Cancer Biology, Microbiology and Medicine, The Howard Hughes Medical Institute, Duke University Medical Center, Durham, NC 27710, USA Corresponding author e-mail:
| | - Joseph Heitman
- Departments of
Genetics, Pharmacology and Cancer Biology, Microbiology and Medicine, The Howard Hughes Medical Institute, Duke University Medical Center, Durham, NC 27710, USA Corresponding author e-mail:
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314
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Affiliation(s)
- G R Crabtree
- Department of Developmental Biology and Department of Pathology, Stanford University Medical School, California 94305, USA.
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315
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Frey N, Richardson JA, Olson EN. Calsarcins, a novel family of sarcomeric calcineurin-binding proteins. Proc Natl Acad Sci U S A 2000; 97:14632-7. [PMID: 11114196 PMCID: PMC18970 DOI: 10.1073/pnas.260501097] [Citation(s) in RCA: 226] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The calcium- and calmodulin-dependent protein phosphatase calcineurin has been implicated in the transduction of signals that control the hypertrophy of cardiac muscle and slow fiber gene expression in skeletal muscle. To identify proteins that mediate the effects of calcineurin on striated muscles, we used the calcineurin catalytic subunit in a two-hybrid screen for cardiac calcineurin-interacting proteins. From this screen, we discovered a member of a novel family of calcineurin-interacting proteins, termed calsarcins, which tether calcineurin to alpha-actinin at the z-line of the sarcomere of cardiac and skeletal muscle cells. Calsarcin-1 and calsarcin-2 are expressed in developing cardiac and skeletal muscle during embryogenesis, but calsarcin-1 is expressed specifically in adult cardiac and slow-twitch skeletal muscle, whereas calsarcin-2 is restricted to fast skeletal muscle. Calsarcins represent a novel family of sarcomeric proteins that link calcineurin with the contractile apparatus, thereby potentially coupling muscle activity to calcineurin activation.
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Affiliation(s)
- N Frey
- Departments of Molecular Biology and Pathology, University of Texas Southwestern Medical Center, 6000 Harry Hines Boulevard, Dallas, TX 75390-9148, USA
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316
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Yang J, Rothermel B, Vega RB, Frey N, McKinsey TA, Olson EN, Bassel-Duby R, Williams RS. Independent signals control expression of the calcineurin inhibitory proteins MCIP1 and MCIP2 in striated muscles. Circ Res 2000; 87:E61-8. [PMID: 11110780 DOI: 10.1161/01.res.87.12.e61] [Citation(s) in RCA: 252] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Calcineurin, a calcium/calmodulin-regulated protein phosphatase, modulates gene expression in cardiac and skeletal muscles during development and in remodeling responses such as cardiac hypertrophy that are evoked by environmental stresses or disease. Recently, we identified two genes encoding proteins (MCIP1 and MCIP2) that are enriched in striated muscles and that interact with calcineurin to inhibit its enzymatic activity. In the present study, we show that expression of MCIP1 is regulated by calcineurin activity in hearts of mice with cardiac hypertrophy, as well as in cultured skeletal myotubes. In contrast, expression of MCIP2 in the heart is not altered by activated calcineurin but responds to thyroid hormone, which has no effect on MCIP1. A approximately 900-bp intragenic segment located between exons 3 and 4 of the MCIP1 gene functions as an alternative promoter that responds to calcineurin. This region includes a dense cluster of 15 consensus binding sites for NF-AT transcription factors. Because MCIP proteins can inhibit calcineurin, these results suggest that MCIP1 participates in a negative feedback circuit to diminish potentially deleterious effects of unrestrained calcineurin activity in cardiac and skeletal myocytes. Inhibitory effects of MCIP2 on calcineurin activity may be pertinent to gene switching events driven by thyroid hormone in striated muscles. The full text of this article is available at http://www. circresaha.org.
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Affiliation(s)
- J Yang
- Departments of Internal Medicine and Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390-8573, USA
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317
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Shiffman D, Mikita T, Tai JT, Wade DP, Porter JG, Seilhamer JJ, Somogyi R, Liang S, Lawn RM. Large scale gene expression analysis of cholesterol-loaded macrophages. J Biol Chem 2000; 275:37324-32. [PMID: 10973959 DOI: 10.1074/jbc.m004732200] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
We conducted large scale gene expression analysis of the response of macrophages to exposure to oxidized low density lipoprotein (Ox-LDL). Much of the vessel wall lesion of atherosclerosis is composed of macrophages that have become engorged with cholesterol. These resulting "foam cells" contribute to the progression of vascular disease through several pathways. As a potential model of foam cell formation, we treated THP-1 cells with 12-O-tetradecanoylphorbol 13-acetate to differentiate them into a macrophage-like phenotype and subsequently treated them with oxidized low density lipoprotein for various time periods. RNA from Ox-LDL treated and time-matched control untreated cells was hybridized to microarrays containing 9808 human genes. 268 genes were found to be at least 2-fold regulated at one or more time points. These regulation patterns were classified into seven clusters of expression profiles. The data is discussed in terms of the overall pattern of gene expression, the thematic classification of the responding genes, and the clustering of functional groups in distinct expression patterns. The magnitude and the temporal patterns of gene expression identified known and novel molecular components of the cellular response that are implicated in the growth, survival, migratory, inflammatory, and matrix remodeling activity of vessel wall macrophages. In particular, the role of nuclear receptors in mediating the gene expression modulation by Ox-LDL is highlighted.
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Affiliation(s)
- D Shiffman
- CV Therapeutics Inc. and Incyte Genomics Inc., Palo Alto, California 94304, USA
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318
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Frey N, McKinsey TA, Olson EN. Decoding calcium signals involved in cardiac growth and function. Nat Med 2000; 6:1221-7. [PMID: 11062532 DOI: 10.1038/81321] [Citation(s) in RCA: 264] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Calcium is central in the regulation of cardiac contractility, growth and gene expression. Variations in the amplitude, frequency and compartmentalization of calcium signals are decoded by calcium/calmodulin-dependent enzymes, ion channels and transcription factors. Understanding the circuitry for calcium signaling creates opportunities for pharmacological modification of cardiac function.
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Affiliation(s)
- N Frey
- Department of Molecular Biology, The University of Texas Southwestern Medical Center, 6000 Harry Hines Boulevard, Dallas, Texas 75390-9148, USA
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319
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Strippoli P, Petrini M, Lenzi L, Carinci P, Zannotti M. The murine DSCR1-like (Down syndrome candidate region 1) gene family: conserved synteny with the human orthologous genes. Gene 2000; 257:223-32. [PMID: 11080588 DOI: 10.1016/s0378-1119(00)00407-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A recently recognized gene family, conserved from yeast to humans, includes Down syndrome candidate region 1 gene (DSCR1), Adapt78 (recognized as the hamster ortholog of the DSCR1 isoform 4), ZAKI-4 (renamed DSCR1-like 1, DSCR1L1) and DSCR1L2 (a novel gene on human chromosome 1), along with yeast and C. elegans single members (Strippoli P., Lenzi L., Petrini M., Carinci P., Zannotti M., 2000. A new gene family including DSCR1 (Down Syndrome Candidate Region 1) and ZAKI-4: characterization from yeast to human and identification of DSCR1-like 2, a novel human member. Genomics 64, 252-263). The proposed family labels were a putative single-strand nucleic acid binding domain similar to the RNA recognition motif, and a unique, highly-conserved serine-proline motif. We have used a bioinformatics-driven molecular biology approach to characterize the murine members of DSCR1-like gene family. Systematic expressed-sequence-tags (EST) database search and reverse-transcription polymerase chain rection (RT-PCR) product sequencing allowed identification of the murine DSCR1, DSCR1L1 and DSCR1L2. The sequences of the respective protein products are of 198, 197 and 241 amino acids, respectively, and are very similar to the corresponding human proteins. The very broad expression pattern of the murine DSCR1 genes is similar to that of the human genes. Using a radiation hybrid panel, we mapped the murine DSCR1-like family members. The murine DSCR1 ortholog is located on the chromosome 16, in a region corresponding to that on human chromosome 21 just upstream of the Down syndrome candidate region. DSCR1L1 and DSCR1L2 murine genes are also located in chromosomal segments of chromosome 17 and 4, respectively, exactly corresponding to those containing the respective human homologs on chromosomes 6 and 1. Description of the mouse orthologs for DSCR1-like genes will allow knockout mice to be obtained for specific family members.
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MESH Headings
- Adaptor Proteins, Signal Transducing
- Amino Acid Sequence
- Animals
- Blotting, Northern
- Chromosome Mapping
- DNA, Complementary/chemistry
- DNA, Complementary/genetics
- DNA-Binding Proteins
- Databases, Factual
- Embryo, Mammalian/metabolism
- Evolution, Molecular
- Expressed Sequence Tags
- Gene Expression
- Gene Expression Regulation, Developmental
- Intracellular Signaling Peptides and Proteins
- Male
- Mice
- Molecular Sequence Data
- Multigene Family/genetics
- Muscle Proteins/genetics
- Phylogeny
- Proteins/genetics
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Radiation Hybrid Mapping
- Sequence Alignment
- Sequence Analysis, DNA
- Sequence Homology, Amino Acid
- Tissue Distribution
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Affiliation(s)
- P Strippoli
- Istituto di Istologia ed Embriologia GeneraleVia Belmeloro, 8-40126 (BO), Bologna, Italy
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320
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Abstract
In response to increased ventricular wall tension or neurohumoral stimuli, the myocardium undergoes an adaptive hypertrophy response that temporarily augments pump function. Although initially beneficial, sustained cardiac hypertrophy can lead to decompensation and cardiomyopathy. Recent studies have focused on characterizing the molecular mechanisms that underlie cardiac hypertrophy. An increasing number of signal transduction pathways have been identified as important regulators of the hypertrophic response, including the low-molecular weight GTPases (Ras, RhoA, and Rac), mitogen-activated protein kinases, protein kinase C, and calcineurin. This review will discuss an emerging body of evidence that implicates the calcium-calmodulin-activated protein phosphatase calcineurin as a physiological regulator of the cardiac hypertrophic response. Although the sufficiency of calcineurin to promote cardiomyocyte hypertrophy in vivo and in vitro is established, its overall necessity as a hypertrophic mediator is currently an area of ongoing debate. The use of the calcineurin-inhibitory agents cyclosporine A and FK506 have suggested a necessary role for calcineurin in many, but not all, animal models of hypertrophy or cardiomyopathy. The evidence implicating a role for calcineurin signaling in the heart will be weighed against a growing body of literature suggesting necessary roles for a diverse array of intracellular signaling pathways, highlighting the multifactorial nature of the hypertrophic program.
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Affiliation(s)
- J D Molkentin
- Department of Pediatrics, University of Cincinnati, Division of Molecular Cardiovascular Biology, Children's Hospital Medical Center, Cincinnati, Ohio, USA.
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321
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Miskin JE, Abrams CC, Dixon LK. African swine fever virus protein A238L interacts with the cellular phosphatase calcineurin via a binding domain similar to that of NFAT. J Virol 2000; 74:9412-20. [PMID: 11000210 PMCID: PMC112370 DOI: 10.1128/jvi.74.20.9412-9420.2000] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The African swine fever virus protein A238L inhibits activation of NFAT transcription factor by binding calcineurin and inhibiting its phosphatase activity. NFAT controls the expression of many immunomodulatory proteins. Here we describe a 14-amino-acid region of A238L that is needed and sufficient for binding to calcineurin. By introducing mutations within this region, we have identified a motif (PxIxITxC/S) required for A238L binding to calcineurin; a similar motif is found in NFAT proteins. Peptides corresponding to this domain of A238L bind calcineurin but do not inhibit its phosphatase activity. Binding of A238L to calcineurin stabilizes the A238L protein in cells. Although A238L-mediated suppression of NF-kappaB-dependent gene expression occurs by a different mechanism, the A238L-calcineurin interaction may be required to stabilize A238L.
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Affiliation(s)
- J E Miskin
- Institute for Animal Health, Pirbright Laboratory, Pirbright, Surrey GU24 0NF, United Kingdom
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322
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Görlach J, Fox DS, Cutler NS, Cox GM, Perfect JR, Heitman J. Identification and characterization of a highly conserved calcineurin binding protein, CBP1/calcipressin, in Cryptococcus neoformans. EMBO J 2000; 19:3618-29. [PMID: 10899116 PMCID: PMC313974 DOI: 10.1093/emboj/19.14.3618] [Citation(s) in RCA: 146] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Calcineurin is the conserved target of the immunosuppressants cyclosporin A and FK506. Using the yeast two-hybrid system, we identified a novel calcineurin binding protein, CBP1, from the pathogenic fungus Cryptococcus neoformans. We show that CBP1 binds to calcineurin in vitro and in vivo, and FKBP12-FK506 inhibits CBP1 binding to calcineurin. Cryptococcus neoformans cbp1 mutant strains exhibit modest defects in growth under stress conditions and virulence, similar to but less severe than the phenotypes of calcineurin mutants. Saccharomyces cerevisiae mutants lacking the CBP1 homolog RCN1 are, like calcineurin mutants, sensitive to lithium cation stress. CBP1 shares a central peptide sequence motif, SPPxSPP, with related proteins in S.CEREVISIAE:, Schizosaccharomyces pombe, Drosophila melanogaster, Caenorhabditis elegans and humans, and peptides containing this motif altered calcineurin activity in vitro. Interestingly, the human CBP1 homolog DSCR1 is encoded by the Down's syndrome candidate region interval on chromosome 21, is highly expressed in the heart and central nervous system, and may play a role in calcineurin functions in heart development, neurite extension and memory.
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Affiliation(s)
- J Görlach
- Departments of Genetics, Medicine, Microbiology, Pharmacology and Cancer Biology, and The Howard Hughes Medical Institute, Duke University Medical Center, Durham, NC 27710, USA
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323
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Abstract
The protein phosphatase calcineurin mediates many cellular responses to calcium signals. Using a genetic screen in yeast, we identified a new family of proteins conserved in fungi and animals that inhibit calcineurin function when overexpressed. Overexpression of the yeast protein Rcn1p or the human homologs DSCR1 or ZAKI-4 inhibited two independent functions of calcineurin in yeast: The activation of the transcription factor Tcn1p and the inhibition of the H+/Ca2+ exchanger Vcx1p. Purified recombinant Rcn1p and DSCR1 bound calcineurin in vitro and inhibited its protein phosphatase activity. Signaling via calmodulin, calcineurin, and Tcn1p induced Rcn1p expression, suggesting that Rcn1p operates as an endogenous feedback inhibitor of calcineurin. Surprisingly, rcn1 null mutants exhibited phenotypes similar to those of Rcn1p-overexpressing cells. This effect may be due to lower expression of calcineurin in rcn1 mutants during signaling conditions. Thus, Rcn1p levels may fine-tune calcineurin signaling in yeast. The structural and functional conservation between Rcn1p and DSCR1 suggests that the mammalian Rcn1p-related proteins, termed calcipressins, will modulate calcineurin signaling in humans and potentially contribute to disorders such as Down Syndrome.
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324
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Abstract
Ca(2+) signaling plays a central role in hypertrophic growth of cardiac and skeletal muscle in response to mechanical load and a variety of signals. However, the mechanisms whereby alterations in Ca(2+) in the cytoplasm activate the hypertrophic response and result in longterm changes in muscle gene expression are unclear. The Ca(2+), calmodulin-dependent protein phosphatase calcineurin has been proposed to control cardiac and skeletal muscle hypertrophy by acting as a Ca(2+) sensor that couples prolonged changes in Ca(2+) levels to reprogramming of muscle gene expression. Calcineurin also controls the contractile and metabolic properties of skeletal muscle by activating the slow muscle fiber-specific gene program, which is dependent on Ca(2+) signaling. Transcription factors of the NFAT and MEF2 families serve as endpoints for the signaling pathways whereby calcineurin controls muscle hypertrophy and fiber-type. We consider these findings in the context of a model for Ca(2+)-regulated gene expression in muscle cells and discuss potential implications of these findings for pharmacologic modification of cardiac and skeletal muscle function. BioEssays 22:510-519, 2000.
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Affiliation(s)
- E N Olson
- Department of Molecular Biology, University of Texas, Southwestern Medical Center at Dallas, Texas.
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325
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Wu H, Naya FJ, McKinsey TA, Mercer B, Shelton JM, Chin ER, Simard AR, Michel RN, Bassel-Duby R, Olson EN, Williams RS. MEF2 responds to multiple calcium-regulated signals in the control of skeletal muscle fiber type. EMBO J 2000; 19:1963-73. [PMID: 10790363 PMCID: PMC305686 DOI: 10.1093/emboj/19.9.1963] [Citation(s) in RCA: 349] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Different patterns of motor nerve activity drive distinctive programs of gene transcription in skeletal muscles, thereby establishing a high degree of metabolic and physiological specialization among myofiber subtypes. Recently, we proposed that the influence of motor nerve activity on skeletal muscle fiber type is transduced to the relevant genes by calcineurin, which controls the functional activity of NFAT (nuclear family of activated T cell) proteins. Here we demonstrate that calcineurin-dependent gene regulation in skeletal myocytes is mediated also by MEF2 transcription factors, and is integrated with additional calcium-regulated signaling inputs, specifically calmodulin-dependent protein kinase activity. In skeletal muscles of transgenic mice, both NFAT and MEF2 binding sites are necessary for properly regulated function of a slow fiber-specific enhancer, and either forced expression of activated calcineurin or motor nerve stimulation up-regulates a MEF2-dependent reporter gene. These results provide new insights into the molecular mechanisms by which specialized characteristics of skeletal myofiber subtypes are established and maintained.
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MESH Headings
- Animals
- Base Sequence
- Calcineurin/genetics
- Calcineurin/metabolism
- Calcium/physiology
- Calcium Signaling
- Calcium-Calmodulin-Dependent Protein Kinase Type 4
- Calcium-Calmodulin-Dependent Protein Kinases/genetics
- Calcium-Calmodulin-Dependent Protein Kinases/metabolism
- Cell Line
- DNA/genetics
- DNA/metabolism
- DNA-Binding Proteins/genetics
- DNA-Binding Proteins/metabolism
- DNA-Binding Proteins/physiology
- Electric Stimulation
- Enhancer Elements, Genetic/genetics
- MEF2 Transcription Factors
- Mice
- Mice, Transgenic
- Motor Neurons/physiology
- Muscle Fibers, Fast-Twitch/cytology
- Muscle Fibers, Fast-Twitch/enzymology
- Muscle Fibers, Fast-Twitch/metabolism
- Muscle Fibers, Skeletal/cytology
- Muscle Fibers, Skeletal/enzymology
- Muscle Fibers, Skeletal/metabolism
- Muscle Fibers, Slow-Twitch/cytology
- Muscle Fibers, Slow-Twitch/enzymology
- Muscle Fibers, Slow-Twitch/metabolism
- Muscle, Skeletal/cytology
- Muscle, Skeletal/enzymology
- Muscle, Skeletal/innervation
- Muscle, Skeletal/metabolism
- Myogenic Regulatory Factors
- NFATC Transcription Factors
- Nuclear Proteins
- Organ Specificity
- Phosphorylation
- Protein Binding
- Transcription Factors/genetics
- Transcription Factors/metabolism
- Transcription Factors/physiology
- Transcriptional Activation
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Affiliation(s)
- H Wu
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
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326
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The Effects of Bioenergetic Stress and Redox Balance on the Expression of Genes Critical to Mitochondrial Function. ACTA ACUST UNITED AC 2000. [DOI: 10.1016/s1568-1254(00)80017-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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