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Schiferl J, Kingston M, Åkesson CM, Valencia BG, Rozas-Davila A, McGee D, Woods A, Chen CY, Hatfield RG, Rodbell DT, Abbott MB, Bush MB. A neotropical perspective on the uniqueness of the Holocene among interglacials. Nat Commun 2023; 14:7404. [PMID: 37973878 PMCID: PMC10654573 DOI: 10.1038/s41467-023-43231-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 11/03/2023] [Indexed: 11/19/2023] Open
Abstract
Understanding how tropical systems have responded to large-scale climate change, such as glacial-interglacial oscillations, and how human impacts have altered those responses is key to current and future ecology. A sedimentary record recovered from Lake Junín, in the Peruvian Andes (4085 m elevation) spans the last 670,000 years and represents the longest continuous and empirically-dated record of tropical vegetation change to date. Spanning seven glacial-interglacial oscillations, fossil pollen and charcoal recovered from the core showed the general dominance of grasslands, although during the warmest times some Andean forest trees grew above their modern limits near the lake. Fire was very rare until the last 12,000 years, when humans were in the landscape. Here we show that, due to human activity, our present interglacial, the Holocene, has a distinctive vegetation composition and ecological trajectory compared with six previous interglacials. Our data reinforce the view that modern vegetation assemblages of high Andean grasslands and the presence of a defined tree line are aspects of a human-modified landscape.
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Affiliation(s)
- J Schiferl
- Institute for Global Ecology, Florida Institute of Technology, Melbourne, FL, 32901, USA
| | - M Kingston
- Institute for Global Ecology, Florida Institute of Technology, Melbourne, FL, 32901, USA
| | - C M Åkesson
- Institute for Global Ecology, Florida Institute of Technology, Melbourne, FL, 32901, USA
| | - B G Valencia
- Facultad de Ciencias de La Tierra y Agua, Universidad Regional Amazónica Ikiam, Tena, Ecuador
| | - A Rozas-Davila
- Institute for Global Ecology, Florida Institute of Technology, Melbourne, FL, 32901, USA
| | - D McGee
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - A Woods
- Department of Geology and Environmental Science, University of Pittsburgh, Pittsburgh, PA, USA
| | - C Y Chen
- Chemical and Isotopic Signatures Group, Nuclear and Chemical Sciences Division, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - R G Hatfield
- Department of Geological Sciences, University of Florida, Gainesville, FL, 32611, USA
| | - D T Rodbell
- Geoscience Department, Union College, Schenectady, NY, 12308, USA
| | - M B Abbott
- Department of Geology and Environmental Science, University of Pittsburgh, Pittsburgh, PA, USA
| | - M B Bush
- Institute for Global Ecology, Florida Institute of Technology, Melbourne, FL, 32901, USA.
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Abbott MB, Furenlid LR, Wilson DW, Stevenson GD, Woolfenden JM, Barrett HH. An Implantable Synthetic SPECT Lesion: A Bridge from Phantom to Reality. J Nucl Med 2007; 48:1796-9. [DOI: 10.2967/jnumed.107.046037] [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] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Fisher DA, Wake C, Kreutz K, Yalcin K, Steig E, Mayewski P, Anderson L, Zheng J, Rupper S, Zdanowicz C, Demuth M, Waszkiewicz M, Dahl-Jensen D, Goto-Azuma K, Bourgeois JB, Koerner RM, Sekerka J, Osterberg E, Abbott MB, Finney BP, Burns SJ. Stable Isotope Records from Mount Logan, Eclipse Ice Cores and Nearby Jellybean Lake. Water Cycle of the North Pacific Over 2000 Years and Over Five Vertical Kilometres: Sudden Shifts and Tropical Connections. ACTA ACUST UNITED AC 2006. [DOI: 10.7202/013147ar] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Abstract
Three ice cores recovered on or near Mount Logan, together with a nearby lake record (Jellybean Lake), cover variously 500 to 30 000 years. This suite of records offers a unique view of the lapse rate in stable isotopes from the lower to upper troposphere. The region is climatologically important, being beside the Cordilleran pinning-point of the Rossby Wave system and the Aleutian Low. Comparison of stable isotope series over the last 2000 years and model simulations suggest sudden and persistent shifts between modern (mixed) and zonal flow regimes of water vapour transport to the Pacific Northwest. The last such shift was in A.D. 1840. Model simulations for modern and “pure” zonal flow suggest that these shifts are consistent regime changes between these flow types, with predominantly zonal flow prior to ca. A.D. 1840 and modern thereafter. The 5.4 and 0.8 km asl records show a shift at A.D. 1840 and another at A.D. 800. It is speculated that the A.D. 1840 regime shift coincided with the end of the Little Ice Age and the A.D. 800 shift with the beginning of the European Medieval Warm Period. The shifts are very abrupt, taking only a few years at most.
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Affiliation(s)
- D. A. Fisher
- Geological Survey of Canada, 601 Booth Street, Ottawa, Ontario K1A 0E8
| | - C. Wake
- Climate Change Research Center, Morse Hall, University of New Hampshire, Durham, New Hampshire 03824, United States
| | - K. Kreutz
- Climate Change Institute and Department of Earth Sciences, University of Maine, Orono, Maine 04469, United States
| | - K. Yalcin
- Climate Change Research Center, Morse Hall, University of New Hampshire, Durham, New Hampshire 03824, United States
| | - E. Steig
- Quaternary Research Center, 19 Johnson Hall, Box 1360, University of Washington, Seattle, Washington 98195, United States
| | - P. Mayewski
- Climate Change Institute and Department of Earth Sciences, University of Maine, Orono, Maine 04469, United States
| | - L. Anderson
- Department of Geosciences, University of Massachusetts-Amherst, Amherst, Massachusetts 01003, United States
| | - J. Zheng
- Geological Survey of Canada, 601 Booth Street, Ottawa, Ontario K1A 0E8
| | - S. Rupper
- Quaternary Research Center, 19 Johnson Hall, Box 1360, University of Washington, Seattle, Washington 98195, United States
| | - C. Zdanowicz
- Geological Survey of Canada, 601 Booth Street, Ottawa, Ontario K1A 0E8
| | - M. Demuth
- Geological Survey of Canada, 601 Booth Street, Ottawa, Ontario K1A 0E8
| | | | - D. Dahl-Jensen
- Niels Bohr Institute, Juliane Maries Vej 30, University of Copenhagen, DK‑2100, Copenhagen East, Danemark
| | - K. Goto-Azuma
- National Institute of Polar Research, Tokyo 173‑8515, Japan
| | - J. B. Bourgeois
- Geological Survey of Canada, 601 Booth Street, Ottawa, Ontario K1A 0E8
| | - R. M. Koerner
- Geological Survey of Canada, 601 Booth Street, Ottawa, Ontario K1A 0E8
| | - J. Sekerka
- Geological Survey of Canada, 601 Booth Street, Ottawa, Ontario K1A 0E8
| | - E. Osterberg
- Climate Change Institute and Department of Earth Sciences, University of Maine, Orono, Maine 04469, United States
| | - M. B. Abbott
- Department of Geology and Planetary Science, University of Pittsburg; Pittsburg, Pennsylvania 15260; United States
| | - B. P. Finney
- Institute of Marine Sciences, University of Alaska Fairbanks, Fairbanks, Alaska 99775, United States
| | - S. J. Burns
- Department of Geosciences, University of Massachusetts-Amherst, Amherst, Massachusetts 01003, United States
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Abstract
The underlying causes of late-Holocene climate variability in the tropics are incompletely understood. Here we report a 1,500-year reconstruction of climate history and glaciation in the Venezuelan Andes using lake sediments. Four glacial advances occurred between anno Domini (A.D.) 1250 and 1810, coincident with solar-activity minima. Temperature declines of -3.2 +/- 1.4 degrees C and precipitation increases of approximately 20% are required to produce the observed glacial responses. These results highlight the sensitivity of high-altitude tropical regions to relatively small changes in radiative forcing, implying even greater probable responses to future anthropogenic forcing.
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Affiliation(s)
- P J Polissar
- Department of Geosciences, Morrill Science Center, University of Massachusetts, Amherst, MA 01003, USA.
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Affiliation(s)
- M B Abbott
- University of California San Francisco School of Medicine, San Francisco, CA, USA
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Abbott MB, Levin RH. Anaphylactoid reactions to radiocontrast agents. Pediatr Rev 2001; 22:356. [PMID: 11581489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Affiliation(s)
- M B Abbott
- University of California San Francisco School of Medicine, San Francisco, CA, USA
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Abstract
We have investigated the binding of bepridil to calcium-saturated cardiac troponin C in a cardiac troponin C/troponin I complex. Nuclear magnetic resonance spectroscopy and [(15)N,(2)H]cardiac troponin C permitted the mapping of bepridil-induced amide proton chemical shifts. A single bepridil-binding site in the regulatory domain was found with an affinity constant of approximately 140 microM(-1). In the presence of cardiac troponin I, bepridil binding to the C domain of cardiac troponin C was not detected. The pattern of bepridil-induced chemical shifts is consistent with stabilization of more open regulatory domain conformational states. A similar pattern of chemical shift perturbations was observed for interaction of the troponin I cardiac-specific amino-terminus with the cardiac troponin C regulatory domain. These results suggest that both bepridil and the cardiac-specific amino-terminus may mediate an increase in calcium affinity by interacting with and stabilizing open regulatory domain conformations. Chemical shift mapping suggests a possible role for inactive calcium-binding site I in the modulation of calcium affinity.
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Affiliation(s)
- E Abusamhadneh
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, College of Medicine, 231 Albert B. Sabin Way, Cincinnati, OH 45267, USA
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Abbott MB, Dong WJ, Dvoretsky A, DaGue B, Caprioli RM, Cheung HC, Rosevear PR. Modulation of cardiac troponin C-cardiac troponin I regulatory interactions by the amino-terminus of cardiac troponin I. Biochemistry 2001; 40:5992-6001. [PMID: 11352734 DOI: 10.1021/bi0100642] [Citation(s) in RCA: 38] [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: 11/30/2022]
Abstract
Multidimensional heteronuclear magnetic resonance studies of the cardiac troponin C/troponin I(1-80)/troponin I(129-166) complex demonstrated that cardiac troponin I(129-166), corresponding to the adjacent inhibitory and regulatory regions, interacts with and induces an opening of the cardiac troponin C regulatory domain. Chemical shift perturbation mapping and (15)N transverse relaxation rates for intact cardiac troponin C bound to either cardiac troponin I(1-80)/troponin I(129-166) or troponin I(1-167) suggested that troponin I residues 81-128 do not interact strongly with troponin C but likely serve to modulate the interaction of troponin I(129-166) with the cardiac troponin C regulatory domain. Chemical shift perturbations due to troponin I(129-166) binding the cardiac troponin C/troponin I(1-80) complex correlate with partial opening of the cardiac troponin C regulatory domain previously demonstrated by distance measurements using fluorescence methodologies. Fluorescence emission from cardiac troponin C(F20W/N51C)(AEDANS) complexed to cardiac troponin I(1-80) was used to monitor binding of cardiac troponin I(129-166) to the regulatory domain of cardiac troponin C. The apparent K(d) for cardiac troponin I(129-166) binding to cardiac troponin C/troponin I(1-80) was 43.3 +/- 3.2 microM. After bisphosphorylation of cardiac troponin I(1-80) the apparent K(d) increased to 59.1 +/- 1.3 microM. Thus, phosphorylation of the cardiac-specific N-terminus of troponin I reduces the apparent binding affinity of the regulatory domain of cardiac troponin C for cardiac troponin I(129-166) and provides further evidence for beta-adrenergic modulation of troponin Ca(2+) sensitivity through a direct interaction between the cardiac-specific amino-terminus of troponin I and the cardiac troponin C regulatory domain.
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Affiliation(s)
- M B Abbott
- Department of Molecular Genetics, Biochemistry, and Microbiology, College of Medicine, University of Cincinnati, Cincinnati, Ohio 45267, USA
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Abstract
OBJECTIVE To describe types of injuries, mechanisms of injury, and treatment of injuries caused by scooter use in children, and to discuss issues of injury prevention in children who use scooters. STUDY DESIGN Data were collected from 14 children seen by a general pediatrician and an orthopedic surgeon over a 3-month period in the summer of 2000. Detailed histories were obtained from patients and their families, and medical records were reviewed. RESULTS Eleven of the 14 patients suffered fractures. The injuries in the other 3 patients were a large abrasion, a laceration, and a septic knee. Half (7) of the children were injured within the first day of riding their scooter, and 13 of the 14 injuries occurred within the first month of scooter use. Only 5 patients used protective gear at the time of their injuries, and those patients were injured in unprotected parts of their bodies. CONCLUSIONS The popularity of scooters presents a new cause of pediatric injuries and a significant health hazard to children. In our study, most injuries occurred shortly after children began scooter use, and younger children suffered the most severe injuries. Additional studies are needed to determine how scooter-related injuries can be prevented or minimized. scooters, injuries.
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Affiliation(s)
- M B Abbott
- East Bay Pediatrics, Berkeley and Orinda, California, USA
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Stein MT, Bennett FC, Abbott MB. Early delay in motor development. J Dev Behav Pediatr 2001; 22:S93-8. [PMID: 11332818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Affiliation(s)
- M T Stein
- University of California, San Diego School of Medicine, USA
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Sorsa T, Heikkinen S, Abbott MB, Abusamhadneh E, Laakso T, Tilgmann C, Serimaa R, Annila A, Rosevear PR, Drakenberg T, Pollesello P, Kilpelainen I. Binding of levosimendan, a calcium sensitizer, to cardiac troponin C. J Biol Chem 2001; 276:9337-43. [PMID: 11113122 DOI: 10.1074/jbc.m007484200] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.6] [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: 11/06/2022] Open
Abstract
Levosimendan is an inodilatory drug that mediates its cardiac effect by the calcium sensitization of contractile proteins. The target protein of levosimendan is cardiac troponin C (cTnC). In the current work, we have studied the interaction of levosimendan with Ca(2+)-saturated cTnC by heteronuclear NMR and small angle x-ray scattering. A specific interaction between levosimendan and the Ca(2+)-loaded regulatory domain of recombinant cTnC(C35S) was observed. The changes in the NMR spectra of the N-domain of full-length cTnC(C35S), due to the binding of levosimendan to the primary site, were indicative of a slow conformational exchange. In contrast, no binding of levosimendan to the regulatory domain of cTnC(A-Cys), where all the cysteine residues are mutated to serine, was detected. Moreover, it was shown that levosimendan was in fast exchange on the NMR time scale with a secondary binding site in the C-domain of both cTnC(C35S) and cTnC(A-Cys). The small angle x-ray scattering experiments confirm the binding of levosimendan to Ca(2+)-saturated cTnC but show no domain-domain closure. The experiments were run in the absence of the reducing agent dithiothreitol and the preservative sodium azide (NaN(3)), since we found that levosimendan reacts with these chemicals, commonly used for preparation of NMR protein samples.
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Affiliation(s)
- T Sorsa
- NMR Laboratory, Institute of Biotechnology, University of Helsinki, P. O. Box 56, FIN-00014 Helsinki, Finland
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Abbott MB, Gaponenko V, Abusamhadneh E, Finley N, Li G, Dvoretsky A, Rance M, Solaro RJ, Rosevear PR. Regulatory domain conformational exchange and linker region flexibility in cardiac troponin C bound to cardiac troponin I. J Biol Chem 2000; 275:20610-7. [PMID: 10801883 DOI: 10.1074/jbc.m909252199] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.8] [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
Previously, we utilized (15)N transverse relaxation rates to demonstrate significant mobility in the linker region and conformational exchange in the regulatory domain of Ca(2+)-saturated cardiac troponin C bound to the isolated N-domain of cardiac troponin I (Gaponenko, V., Abusamhadneh, E., Abbott, M. B., Finley, N., Gasmi-Seabrook, G., Solaro, R.J., Rance, M., and Rosevear, P.R. (1999) J. Biol. Chem. 274, 16681-16684). Here we show a large decrease in cardiac troponin C linker flexibility, corresponding to residues 85-93, when bound to intact cardiac troponin I. The addition of 2 m urea to the intact cardiac troponin I-troponin C complex significantly increased linker flexibility. Conformational changes in the regulatory domain of cardiac troponin C were monitored in complexes with troponin I-(1-211), troponin I-(33-211), troponin I-(1-80) and bisphosphorylated troponin I-(1-80). The cardiac specific N terminus, residues 1-32, and the C-domain, residues 81-211, of troponin I are both capable of inducing conformational changes in the troponin C regulatory domain. Phosphorylation of the cardiac specific N terminus reversed its effects on the regulatory domain. These studies provide the first evidence that the cardiac specific N terminus can modulate the function of troponin C by altering the conformational equilibrium of the regulatory domain.
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Affiliation(s)
- M B Abbott
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, College of Medicine, Cincinnati, Ohio 45267, USA
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Abstract
Cardiac troponin I(129-149) binds to the calcium saturated cardiac troponin C/troponin I(1-80) complex at two distinct sites. Binding of the first equivalent of troponin I(129-149) was found to primarily affect amide proton chemical shifts in the regulatory domain, while the second equivalent perturbed amide proton chemical shifts within the D/E linker region. Nitrogen-15 transverse relaxation rates showed that binding the first equivalent of inhibitory peptide to the regulatory domain decreased conformational exchange in defunct calcium binding site I and that addition of the second equivalent of inhibitory peptide decreased flexibility in the D/E linker region. No interactions between the inhibitory peptide and the C-domain of cardiac troponin C were detected by these methods demonstrating that the inhibitory peptide cannot displace cTnI(1-80) from the C-domain.
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Affiliation(s)
- M B Abbott
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, College of Medicine, 231 Bethesda Ave., Cincinnati, OH 45267, USA
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Finley N, Abbott MB, Abusamhadneh E, Gaponenko V, Dong W, Gasmi-Seabrook G, Howarth JW, Rance M, Solaro RJ, Cheung HC, Rosevear PR. NMR analysis of cardiac troponin C-troponin I complexes: effects of phosphorylation. FEBS Lett 1999; 453:107-12. [PMID: 10403385 DOI: 10.1016/s0014-5793(99)00693-6] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.3] [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: 11/19/2022]
Abstract
Phosphorylation of the cardiac specific amino-terminus of troponin I has been demonstrated to reduce the Ca2+ affinity of the cardiac troponin C regulatory site. Recombinant N-terminal cardiac troponin I proteins, cardiac troponin I(33-80), cardiac troponin I(1-80), cardiac troponin I(1-80)DD and cardiac troponin I(1-80)pp, phosphorylated by protein kinase A, were used to form stable binary complexes with recombinant cardiac troponin C. Cardiac troponin I(1-80)DD, having phosphorylated Ser residues mutated to Asp, provided a stable mimetic of the phosphorylated state. In all complexes, the N-terminal domain of cardiac troponin I primarily makes contact with the C-terminal domain of cardiac troponin C. The nonphosphorylated cardiac specific amino-terminus, cardiac troponin I(1-80), was found to make additional interactions with the N-terminal domain of cardiac troponin C.
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Affiliation(s)
- N Finley
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, College of Medicine, OH 45267, USA
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Gaponenko V, Abusamhadneh E, Abbott MB, Finley N, Gasmi-Seabrook G, Solaro RJ, Rance M, Rosevear PR. Effects of troponin I phosphorylation on conformational exchange in the regulatory domain of cardiac troponin C. J Biol Chem 1999; 274:16681-4. [PMID: 10358006 DOI: 10.1074/jbc.274.24.16681] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.6] [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: 11/06/2022] Open
Abstract
Conformational exchange has been demonstrated within the regulatory domain of calcium-saturated cardiac troponin C when bound to the NH2-terminal domain of cardiac troponin I-(1-80), and cardiac troponin I-(1-80)DD, having serine residues 23 and 24 mutated to aspartate to mimic the phosphorylated form of the protein. Binding of cardiac troponin I-(1-80) decreases conformational exchange for residues 29, 32, and 34. Comparison of average transverse cross correlation rates show that both the NH2- and COOH-terminal domains of cardiac troponin C tumble with similar correlation times when bound to cardiac troponin I-(1-80). In contrast, the NH2- and COOH-terminal domains in free cardiac troponin C and cardiac troponin C bound cardiac troponin I-(1-80)DD tumble independently. These results suggest that the nonphosphorylated cardiac specific NH2 terminus of cardiac troponin I interacts with the NH2-terminal domain of cardiac troponin C.
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Affiliation(s)
- V Gaponenko
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, College of Medicine, Cincinnati, Ohio 45267, USA
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Rodbell DT, Seltzer GO, Anderson DM, Abbott MB, Enfield DB, Newman JH. An approximately 15,000-year record of El Nino-driven alluviation in southwestern ecuador. Science 1999; 283:516-20. [PMID: 9915694 DOI: 10.1126/science.283.5401.516] [Citation(s) in RCA: 572] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Debris flows have deposited inorganic laminae in an alpine lake that is 75 kilometers east of the Pacific Ocean, in Ecuador. These storm-induced events were dated by radiocarbon, and the age of laminae that are less than 200 years old matches the historic record of El Nino events. From about 15,000 to about 7000 calendar years before the present, the periodicity of clastic deposition is greater than or equal to 15 years; thereafter, there is a progressive increase in frequency to periodicities of 2 to 8.5 years. This is the modern El Nino periodicity, which was established about 5000 calendar years before the present. This may reflect the onset of a steeper zonal sea surface temperature gradient, which was driven by enhanced trade winds.
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Affiliation(s)
- DT Rodbell
- D. T. Rodbell and J. H. Newman, Department of Geology, Union College, Schenectady, NY 12308-2311, USA. G. O. Seltzer, Department of Earth Sciences, Syracuse University, Syracuse, NY 13244-1070, USA. D. M. Anderson, National Oceanic and Atmospheric Adm
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Abbott MB, Oken RL, Grossman M. Pediatrics. West J Med 1997; 166:337. [PMID: 18751076 PMCID: PMC1304230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
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Affiliation(s)
- M T Stein
- University of California, San Diego School of Medicine, USA
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