U-8211 MCN (Learned Labs)
Office @ U-8211 MCN (Learned Labs) Mail @ Box 1634 Sta B 37235
Circadian, Calcium, Cyanobacteria, Transgenic mice, Cell cycle, Gene regulation, Microbiology,
structure,Signal transduction, luciferase,Bacteria,Biochemistry,Cell cycle,Diabetes,Gene regulation,Genetics,Human Genetics,Knockout,Microbiology,Mouse,Neuroscience,Phosphorylation,Polymorphism,Post-transcriptional modification,Protein Structure,Signal transduction,Structural Biology
Cellular and Molecular Biology of Biological Clocks
Organisms and even single cells have endogenous biological "clocks" that allow them to tell the time of day. Research in our laboratory is directed towards understanding the cellular and molecular bases of these fascinating timing mechanisms in a variety of organisms: cyanobacteria ("blue-green algae"), plants, and animals. To analyze the molecular nature of the clock in the prokaryotic cyanobacteria, we have developed a bioluminescent reporter strain that expresses a daily rhythm of light emission. Using this bioluminescence rhythm as a marker, clock mutants have been identified. We found that the essential clock gene, KaiC, is rhythmically expressed and forms ATP-dependent hexamers. In collaboration with the laboratory of Dr. Martin Egli, we have crystallized KaiC to determine its three-dimensional structure and discover its phosphorylation sites. The three key bacterial clock proteins (KaiA + KaiB + KaiC) will show circadian oscillations in a test tube! In collaboration with the laboratories of Drs. Phoebe Stewart and Hassane Mchaourab, we are applying electron microscopic and biophysical methods to explain how these proteins oscillate in vitro. Furthermore, we are using clock mutants of cyanobacteria to provide the first rigorous evidence for the adaptive significance of circadian clocks in fitness.
We also study the neuroscience of the circadian system of mammals. To measure circadian rhythms in brain slices in vitro, we use transgenic mice that express luciferase rhythmically. As a model system, we have also created a fibroblast cell line that is stably transfected with a luciferase reporter and glows rhythmically. Therefore, we use luminescence as a tool to monitor circadian rhythms in the brain. Future studies will focus upon understanding the signal transduction pathway of calcium to the clock and the role of clock genes in the fundamental mammalian clockwork.
We have recently extended our studies to the genetics of the human biological clock. We are examining clock gene polymorphisms in human populations to determine how the neurogenetics of the biological clock affects our ability to adapt to shiftwork cycles and how it can influence mental health (esp. depression). Because daily biological clocks control a myriad of fundamental cellular activities, including cell division, metabolism, gene expression, and ion channel, the elucidation of the timing mechanism will have ramifications for many aspects of temporal regulation, including mental health, cancer, and jet lag.
Finally, we have developed a new method for measuring protein-protein interactions based upon the resonance energy between a luciferase and a fluorescent protein. This method is called Bioluminescence Resonance Energy Transfer, or BRET. This technique has allowed us to develop novel reporters for intracellular calcium and hydrogen ions. We envision a bright future for this technique.
See our laboratory website at: http://www.cas.vanderbilt.edu/johnsonlab/
Egli, M, Pattanayek, R, Sheehan, JH, Xu, Y, Mori, T, Smith, JA, Johnson, CH. Loop-Loop Interactions Regulate KaiA-Stimulated KaiC Phosphorylation in the Cyanobacterial KaiABC Circadian Clock. Biochemistry, 52(7), 1208-20, 2013.
Shi, SQ, Ansari, TS, McGuinness, OP, Wasserman, DH, Johnson, CH. Circadian Disruption Leads to Insulin Resistance and Obesity. Curr Biol, 23, 372-381, 2013.
Xu, Y, Ma, P, Shah, P, Rokas, A, Liu, Y, Johnson, CH. Non-optimal codon usage is a mechanism to achieve circadian clock conditionality. Nature, 495(7439), 116-20, 2013.
Edgar, R.S., E.W. Green, Y. Zhao, G. van Ooijen, M. Olmedo, X. Qin, Y. Xu, M. Pan, U.K. Valekunja, K.A. Feeney, E.S. Maywood, M.H. Hastings, N.S. Baliga, M. Merrow, A.J. Millar, C.H. Johnson, C.P. Kyriacou, J.S. Oa??Neill, A.B. Reddy. . Peroxiredoxins are conserved markers of circadian rhythms. . Nature, 485, 459-64, 2012.
Egli, M, Mori, T, Pattanayek, R, Xu, Y, Qin, X, Johnson, CH. Dephosphorylation of the core clock protein KaiC in the cyanobacterial KaiABC circadian oscillator proceeds via an ATP synthase mechanism. Biochemistry, 51(8), 1547-58, 2012.
Zhang, Y, Xie, Q, Robertson, JB, Johnson, CH. pHlash: a new genetically encoded and ratiometric luminescence sensor of intracellular pH. PLoS One, 7(8), e43072, 2012.
Gamble, KL, Motsinger-Reif, AA, Hida, A, Borsetti, HM, Servick, SV, Ciarleglio, CM, Robbins, S, Hicks, J, Carver, K, Hamilton, N, Wells, N, Summar, ML, McMahon, DG, Johnson, CH. Shift work in nurses: contribution of phenotypes and genotypes to adaptation. PLoS One, 6(4), e18395, 2011.
Johnson, CH, Stewart, PL, Egli, M. The cyanobacterial circadian system: from biophysics to bioevolution. Annu Rev Biophys, 40, 143-67, 2011.
Pattanayek, R, Williams, DR, Rossi, G, Weigand, S, Mori, T, Johnson, CH, Stewart, PL, Egli, M. Combined SAXS/EM based models of the S. elongatus post-translational circadian oscillator and its interactions with the output His-kinase SasA. PLoS One, 6(8), e23697, 2011.
Robertson, JB, Johnson, CH. Luminescence as a continuous real-time reporter of promoter activity in yeast undergoing respiratory oscillations or cell division rhythms. Methods Mol Biol, 734, 63-79, 2011.
Xie, Q, Soutto, M, Xu, X, Zhang, Y, Johnson, CH. Bioluminescence resonance energy transfer (BRET) imaging in plant seedlings and mammalian cells. Methods Mol Biol, 680, 3-28, 2011.
Johnson, CH. Circadian clocks and cell division: What's the pacemaker?. Cell Cycle, 9(19), , 2010.
Qin, X, Byrne, M, Mori, T, Zou, P, Williams, DR, McHaourab, H, Johnson, CH. Intermolecular associations determine the dynamics of the circadian KaiABC oscillator. Proc Natl Acad Sci U S A, 107(33), 14805-10, 2010.
Qin, X, Byrne, M, Xu, Y, Mori, T, Johnson, CH. Coupling of a core post-translational pacemaker to a slave transcription/translation feedback loop in a circadian system. PLoS Biol, 8(6), e1000394, 2010.
Shi, S, Hida, A, McGuinness, OP, Wasserman, DH, Yamazaki, S, Johnson, CH. Circadian clock gene Bmal1 is not essential; functional replacement with its paralog, Bmal2. Curr Biol, 20(4), 316-21, 2010.
J.L. Ditty, S.R. Mackey, C.H. Johnson, editors. Bacterial Circadian Programs. , , 333 pages, 2009.
Pattanayek, R, Mori, T, Xu, Y, Pattanayek, S, Johnson, CH, Egli, M. Structures of KaiC circadian clock mutant proteins: a new phosphorylation site at T426 and mechanisms of kinase, ATPase and phosphatase. PLoS One, 4(11), e7529, 2009.
Robertson, JB, Zhang, Y, Johnson, CH. Light-emitting diode flashlights as effective and inexpensive light sources for fluorescence microscopy. J Microsc, 236(1), 1-4, 2009.
Xu, X, Graeff, R, Xie, Q, Gamble, KL, Mori, T, Johnson, CH. Comment on "The Arabidopsis circadian clock incorporates a cADPR-based feedback loop". Science, 326(5950), 230; author reply 230, 2009.
Xu, Y, Mori, T, Qin, X, Yan, H, Egli, M, Johnson, CH. Intramolecular regulation of phosphorylation status of the circadian clock protein KaiC. PLoS One, 4(11), e7509, 2009.
Ciarleglio, CM, Ryckman, KK, Servick, SV, Hida, A, Robbins, S, Wells, N, Hicks, J, Larson, SA, Wiedermann, JP, Carver, K, Hamilton, N, Kidd, KK, Kidd, JR, Smith, JR, Friedlaender, J, McMahon, DG, Williams, SM, Summar, ML, Johnson, CH. Genetic differences in human circadian clock genes among worldwide populations. J Biol Rhythms, 23(4), 330-40, 2008.
Johnson, CH, Egli, M, Stewart, PL. Structural insights into a circadian oscillator. Science, 322(5902), 697-701, 2008.
Johnson, CH, Mori, T, Xu, Y. A cyanobacterial circadian clockwork. Curr Biol, 18(17), R816-R825, 2008.
Pattanayek, R, Williams, DR, Pattanayek, S, Mori, T, Johnson, CH, Stewart, PL, Egli, M. Structural model of the circadian clock KaiB-KaiC complex and mechanism for modulation of KaiC phosphorylation. EMBO J, 27(12), 1767-78, 2008.
Robertson, JB, Stowers, CC, Boczko, E, Johnson, CH. Real-time luminescence monitoring of cell-cycle and respiratory oscillations in yeast. Proc Natl Acad Sci U S A, 105(46), 17988-93, 2008.
Vougogiannopoulou, K, Ferandin, Y, Bettayeb, K, Myrianthopoulos, V, Lozach, O, Fan, Y, Johnson, CH, Magiatis, P, Skaltsounis, AL, Mikros, E, Meijer, L. Soluble 3'',6-substituted indirubins with enhanced selectivity toward glycogen synthase kinase -3 alter circadian period. J Med Chem, 51(20), 6421-31, 2008.
Bonneau, R, Facciotti, MT, Reiss, DJ, Schmid, AK, Pan, M, Kaur, A, Thorsson, V, Shannon, P, Johnson, MH, Bare, JC, Longabaugh, W, Vuthoori, M, Whitehead, K, Madar, A, Suzuki, L, Mori, T, Chang, DE, Diruggiero, J, Johnson, CH, Hood, L, Baliga, NS. A predictive model for transcriptional control of physiology in a free living cell. Cell, 131(7), 1354-65, 2007.
Fan, Y, Hida, A, Anderson, DA, Izumo, M, Johnson, CH. Cycling of CRYPTOCHROME proteins is not necessary for circadian-clock function in mammalian fibroblasts. Curr Biol, 17(13), 1091-100, 2007.
Johnson, CH. Bacterial circadian programs. Cold Spring Harb Symp Quant Biol, 72, 395-404, 2007.
Mori, T, Williams, DR, Byrne, MO, Qin, X, Egli, M, McHaourab, HS, Stewart, PL, Johnson, CH. Elucidating the Ticking of an In Vitro Circadian Clockwork. PLoS Biol, 5(4), e93, 2007.
Woelfle, MA, Xu, Y, Qin, X, Johnson, CH. Circadian rhythms of superhelical status of DNA in cyanobacteria. Proc Natl Acad Sci U S A, 104(47), 18819-24, 2007.
Xu, X, Hotta, CT, Dodd, AN, Love, J, Sharrock, R, Lee, YW, Xie, Q, Johnson, CH, Webb, AA. Distinct light and clock modulation of cytosolic free Ca2+ oscillations and rhythmic CHLOROPHYLL A/B BINDING PROTEIN2 promoter activity in Arabidopsis. Plant Cell, 19(11), 3474-90, 2007.
Xu, X, Soutto, M, Xie, Q, Servick, S, Subramanian, C, von Arnim, AG, Johnson, CH. Imaging protein interactions with bioluminescence resonance energy transfer (BRET) in plant and mammalian cells and tissues. Proc Natl Acad Sci U S A, 104(24), 10264-9, 2007.
Izumo, M, Sato, TR, Straume, M, Johnson, CH. Quantitative analyses of circadian gene expression in mammalian cell cultures. PLoS Comput Biol, 2(10), e136, 2006.
Johnson, C.H.. Reminiscences from Pittendrigh's last Ph.D. student. Resonance, 11, 22-31, 2006.
Johnson, C.H., R. Shingles, and W.F. Ettinger. Regulation and role of Ca++ fluxes in the chloroplast. In: The Structure and Function of Plastids, Chapter 20, 23, 403-416, 2006.
Johnson, C.H., and S.S. Golden. Circadian Rhythms in Cyanobacteria. In: Nature Encyclopedia of Life Sciences, Nature Publishing Group, London: www.els.net, , , 2006.
Pattanayek, R, Williams, DR, Pattanayek, S, Xu, Y, Mori, T, Johnson, CH, Stewart, PL, Egli, M. Analysis of KaiA-KaiC protein interactions in the cyano-bacterial circadian
clock using hybrid structural methods. EMBO J, 25(9), 2017-28, 2006.
Subramanian, C, Woo, J, Cai, X, Xu, X, Servick, S, Johnson, CH, Nebenf??hr, A, von Arnim, AG. A suite of tools and application notes for in vivo protein interaction assays using bioluminescence resonance energy transfer (BRET). Plant J, 48(1), 138-52, 2006.
Woelfle, MA, Johnson, CH. No promoter left behind: global circadian gene expression in cyanobacteria. J Biol Rhythms, 21(6), 419-31, 2006.
Johnson, C.H. Testing the adaptive value of circadian systems. Methods in Enzymology, 393, 818-837, 2005.
Johnson, C.H. and C.P. Kyriacou. Clock evolution and adaptation: whence and whither?. In: Endogenous Plant Rhythms , (Chapter 10), 237-260, 2005.
Johnson, CH. Testing the adaptive value of circadian systems. Methods Enzymol, 393, 818-37, 2005.
Mittag, M, Kiaulehn, S, Johnson, CH. The circadian clock in Chlamydomonas reinhardtii. What is it for? What is it similar to. Plant Physiol, 137(2), 399-409, 2005.
Soutto M., Y. Xu, and C. H. Johnson. Bioluminescence RET (BRET): techniques and potential. In: Molecular Imaging: FRET Microscopy and Spectroscopy, , 260-271, 2005.
Johnson, C.H.. As time glows by in bacteria. Nature , 430(1), 23-24, 2004.
Johnson, C.H. and M. Egli. Visualizing a biological clockwork's cogs. Nature Structural and Molecular Biology, 11(7), 584-585, 2004.
Johnson, Carl Hirschie. Precise circadian clocks in prokaryotic cyanobacteria. Curr Issues Mol Biol, 6(2), 103-10, 2004.
Johnson, Carl Hirschie. Global orchestration of gene expression by the biological clock of cyanobacteria. Genome Biol, 5(4), 217, 2004.
Min, H, Liu, Y, Johnson, CH, Golden, SS. Phase determination of circadian gene expression in Synechococcus elongatus PCC 7942. J Biol Rhythms, 19(2), 103-12, 2004.
Pattanayek, R, Wang, J, Mori, T, Xu, Y, Johnson, CH, Egli, M. Visualizing a circadian clock protein: crystal structure of KaiC and functional
insights. Mol Cell, 15(3), 375-88, 2004.
Subramanian, C, Kim, BH, Lyssenko, NN, Xu, X, Johnson, CH, von Arnim, AG. The Arabidopsis repressor of light signaling, COP1, is regulated by nuclear exclusion: mutational analysis by bioluminescence resonance energy transfer. Proc Natl Acad Sci U S A, 101(17), 6798-802, 2004.
Subramanian, C, Xu, Y, Johnson, CH, von Arnim, AG. In vivo detection of protein-protein interaction in plant cells using BRET. Methods Mol Biol, 284, 271-86, 2004.
Woelfle, MA, Ouyang, Y, Phanvijhitsiri, K, Johnson, CH. The adaptive value of circadian clocks: an experimental assessment in cyanobacteria. Curr Biol, 14(16), 1481-6, 2004.
Xu, Y, Mori, T, Pattanayek, R, Pattanayek, S, Egli, M, Johnson, CH. Identification of key phosphorylation sites in the circadian clock protein
KaiC by crystallographic and mutagenetic analyses. Proc Natl Acad Sci U S A, 101(38), 13933-8, 2004.
Hastings, JW, Johnson, CH. Bioluminescence and chemiluminescence. Methods Enzymol, 360, 75-104, 2003.
Izumo, Mariko, Johnson, Carl Hirschie, Yamazaki, Shin. Circadian gene expression in mammalian fibroblasts revealed by real-time luminescence reporting: temperature compensation and damping. Proc Natl Acad Sci U S A, 100(26), 16089-94, 2003.
Johnson, Carl Hirschie, Elliott, Jeffrey A, Foster, Russell. Entrainment of circadian programs. Chronobiol Int, 20(5), 741-74, 2003.
Schoenhard, John A, Smith, Layton H, Painter, Corrie A, Eren, Mesut, Johnson, Carl H, Vaughan, Douglas E. Regulation of the PAI-1 promoter by circadian clock components: differential activation by BMAL1 and BMAL2. J Mol Cell Cardiol, 35, 473-81, 2003.
Xu, Yao, Kanauchi, Akihito, von Arnim, Albrecht G, Piston, David W, Johnson, Carl Hirschie. Bioluminescence resonance energy transfer: monitoring protein-protein interactions in living cells. Methods Enzymol, 360, 289-301, 2003.
Xu, Yao, Mori, Tetsuya, Johnson, Carl Hirschie. Cyanobacterial circadian clockwork: roles of KaiA, KaiB and the kaiBC promoter in regulating KaiC. EMBO J, 22, 2117-26, 2003.
Mori, T., and C.H. Johnson. Circadian control of cell division in unicellular organisms. In: Progress in Cell Cycle Research, Volume 4. L. Meijer, A. Jezequel, an dB. Ducommun, eds. (Kluwer Academic/Plenum Press, N.Y.), pp. 185-192, 2002.
Xu, Y., A. Kanauchi, D.W. Piston, and C.H. Johnson. Resonance
energy transfer as an emerging technique for monitoring protein-protein
interactions in vivo: BRET vs. FRET. In: Luminescence BioTechnology, K.
Van Dyke, C. Van Dyke and K. Woodfork, eds. (CRC Press, N.Y.), pp.
Mori, Tetsuya, Saveliev, Sergei V, Xu, Yao, Stafford, Walter F, Cox, Michael M, Inman, Ross B, Johnson, Carl H. Circadian clock protein KaiC forms ATP-dependent hexameric rings and binds DNA. Proc Natl Acad Sci U S A, 99, 17203-8, 2002.
Sai, Jiqing, Johnson, Carl Hirschie. Dark-stimulated calcium ion fluxes in the chloroplast stroma and cytosol. Plant Cell, 14, 1279-91, 2002.
Schoenhard, John A, Eren, Mesut, Johnson, Carl H, Vaughan, Douglas E. Alternative splicing yields novel BMAL2 variants: tissue distribution and functional characterization. Am J Physiol Cell Physiol, 283, C103-14, 2002.
Suzuki, Lena, Johnson, Carl Hirschie. Photoperiodic control of germination in the unicell Chlamydomonas. Naturwissenschaften, 89, 214-20, 2002.
Xu, Yao, Johnson, Carl Hirschie, Piston, David. Bioluminescence resonance energy transfer assays for protein-protein interactions in living cells. Methods Mol Biol, 183, 121-33, 2002.
Dassarma, S, Kennedy, SP, Berquist, B, Victor Ng, W, Baliga, NS, Spudich, JL, Krebs, MP, Eisen, JA, Johnson, CH, Hood, L. Genomic perspective on the photobiology of Halobacterium species NRC-1, a phototrophic, phototactic, and UV-tolerant haloarchaeon. Photosynth Res, 70(1), 3-17, 2001.
Johnson, C H. Endogenous timekeepers in photosynthetic organisms. Annu Rev Physiol, 63, 695-728, 2001.
Mori, T, Johnson, C H. Circadian programming in cyanobacteria. Semin Cell Dev Biol, 12, 271-8, 2001.
Mori, T, Johnson, C H. Independence of circadian timing from cell division in cyanobacteria. J Bacteriol, 183, 2439-44, 2001.
Xu, Y, Johnson, C H. A clock- and light-regulated gene that links the circadian oscillator to LHCB gene expression. Plant Cell, 13, 1411-25, 2001.
Mori, T, Johnson, C H. Circadian control of cell division in unicellular organisms. Prog Cell Cycle Res, 4, 185-92, 2000.
Nikaido, S S, Johnson, C H. Daily and circadian variation in survival from ultraviolet radiation in Chlamydomonas reinhardtii. Photochem Photobiol, 71(6), 758-65, 2000.
Xu, Y, Mori, T, Johnson, C H. Circadian clock-protein expression in cyanobacteria: rhythms and phase setting. EMBO J, 19(13), 3349-57, 2000.
Johnson, C H. Forty years of PRCs--what have we learned. Chronobiol Int, 16(6), 711-43, 1999.
Johnson, C H, Golden, S S. Circadian programs in cyanobacteria: adaptiveness and mechanism. Annu Rev Microbiol, 53, 389-409, 1999.
Sai, J, Johnson, C H. Different circadian oscillators control Ca(2+) fluxes and lhcb gene expression. Proc Natl Acad Sci U S A, 96(20), 11659-63, 1999.
Xu, Y, Piston, D W, Johnson, C H. A bioluminescence resonance energy transfer (BRET) system: application to interacting circadian clock proteins. Proc Natl Acad Sci U S A, 96(1), 151-6, 1999.
Johnson, C.H., M. Knight, A. Trewavas, and T. Kondo. A clockwork green: circadian programs in photosynthetic organisms. Chapter 1 in: Biological Rhythms and Photoperiodism in Plants. P. Lumsden and A. Millar, eds. (BIOS Scientific Publishers, Oxford), pp. 1-34, 1998.
Golden, SS, Johnson, CH, Kondo, T. The cyanobacterial circadian system: a clock apart. Curr Opin Microbiol, 1(6), 669-73, 1998.
Ishiura, M, Kutsuna, S, Aoki, S, Iwasaki, H, Andersson, CR, Tanabe, A, Golden, SS, Johnson, CH, Kondo, T. Expression of a gene cluster kaiABC as a circadian feedback process in cyanobacteria. Science, 281(5382), 1519-23, 1998.
Johnson, C H, Golden, S S, Kondo, T. Adaptive significance of circadian programs in cyanobacteria. Trends Microbiol, 6(10), 407-10, 1998.
Ouyang, Y, Andersson, C R, Kondo, T, Golden, S S, Johnson, C H. Resonating circadian clocks enhance fitness in cyanobacteria. Proc Natl Acad Sci U S A, 95(15), 8660-4, 1998.
Golden, Susan S., Ishiura, Masahiro, Johnson, Carl Hirschie, Kondo, Takao. CYANOBACTERIAL CIRCADIAN RHYTHMS. Annu Rev Plant Physiol Plant Mol Biol, 48, 327-354, 1997.
Jacobshagen, S, Kindle, K L, Johnson, C H. Transcription of CABII is regulated by the biological clock in Chlamydomonas reinhardtii. Plant Mol Biol, 31(6), 1173-84, 1996.
Johnson, C H, Golden, S S, Ishiura, M, Kondo, T. Circadian clocks in prokaryotes. Mol Microbiol, 21(1), 5-11, 1996.
Liu, Y, Tsinoremas, N F, Golden, S S, Kondo, T, Johnson, C H. Circadian expression of genes involved in the purine biosynthetic pathway of the cyanobacterium Synechococcus sp. strain PCC 7942. Mol Microbiol, 20(5), 1071-81, 1996.
Mori, T, Binder, B, Johnson, CH. Circadian gating of cell division in cyanobacteria growing with average doubling times of less than 24 hours. Proc Natl Acad Sci U S A, 93(19), 10183-8, 1996.
Tsinoremas, NF, Ishiura, M, Kondo, T, Andersson, CR, Tanaka, K, Takahashi, H, Johnson, CH, Golden, SS. A sigma factor that modifies the circadian expression of a subset of genes in cyanobacteria. EMBO J, 15(10), 2488-95, 1996.
Goto, K, Johnson, CH. Is the cell division cycle gated by a circadian clock? The case of Chlamydomonas reinhardtii. J Cell Biol, 129(4), 1061-9, 1995.
Johnson, C H, Knight, M R, Kondo, T, Masson, P, Sedbrook, J, Haley, A, Trewavas, A. Circadian oscillations of cytosolic and chloroplastic free calcium in plants. Science, 269(5232), 1863-5, 1995.
Liu, Y, Golden, S S, Kondo, T, Ishiura, M, Johnson, C H. Bacterial luciferase as a reporter of circadian gene expression in cyanobacteria. J Bacteriol, 177(8), 2080-6, 1995.
Liu, Y, Tsinoremas, N F, Johnson, C H, Lebedeva, N V, Golden, S S, Ishiura, M, Kondo, T. Circadian orchestration of gene expression in cyanobacteria. Genes Dev, 9(12), 1469-78, 1995.
Jacobshagen, S, Johnson, C H. Circadian rhythms of gene expression in Chlamydomonas reinhardtii: circadian cycling of mRNA abundances of cab II, and possibly of beta-tubulin and cytochrome c. Eur J Cell Biol, 64(1), 142-52, 1994.
Johnson, C H. Illuminating the clock: circadian photobiology. Semin Cell Biol, 5(5), 355-62, 1994.
Johnson, C H, Nakaoka, Y, Miwa, I. The effects of altering extracellular potassium ion concentration on the membrane potential and circadian clock of Paramecium bursaria. J Exp Biol, 197, 295-308, 1994.
Kondo, T, Tsinoremas, NF, Golden, SS, Johnson, CH, Kutsuna, S, Ishiura, M. Circadian clock mutants of cyanobacteria. Science, 266(5188), 1233-6, 1994.
Kondo, T, Strayer, CA, Kulkarni, RD, Taylor, W, Ishiura, M, Golden, SS, Johnson, CH. Circadian rhythms in prokaryotes: luciferase as a reporter of circadian gene expression in cyanobacteria. Proc Natl Acad Sci U S A, 90(12), 5672-6, 1993.
Johnson, C H, Kondo, T. Light pulses induce 'singular' behavior and shorten the period of the circadian phototaxis rhythm in the CW15 strain of Chlamydomonas. J Biol Rhythms, 7(4), 313-27, 1992.
Johnson, CH, Kondo, T, Hastings, JW. Action Spectrum for Resetting the Circadian Phototaxis Rhythm in the CW15 Strain
of Chlamydomonas: II. Illuminated Cells. Plant Physiol, 97(3), 1122-1129, 1991.
Kondo, T, Johnson, CH, Hastings, JW. Action Spectrum for Resetting the Circadian Phototaxis Rhythm in the CW15 Strain of Chlamydomonas: I. Cells in Darkness. Plant Physiol, 95(1), 197-205, 1991.
Johnson, C. H. An Atlas of Phase Response Curves for Circadian and Circatidal Rhythms. Dept. of Biology, Vanderbilt University, 715 pages, 1990.
Johnson, C H, Nakashima, H. Cycloheximide inhibits light-induced phase shifting of the circadian clock in Neurospora. J Biol Rhythms, 5(2), 159-67, 1990.
Broda, H, Johnson, CH, Taylor, WR, Hastings, JW. Temperature dependence of phase response curves for drug-induced phase shifts. J Biol Rhythms, 4(3), 327-33, 1989.
Johnson, C H, Hastings, J W. Circadian phototransduction: phase resetting and frequency of the circadian clock of Gonyaulax cells in red light. J Biol Rhythms, 4(4), 417-37, 1989.
Johnson, C H, Miwa, I, Kondo, T, Hastings, J W. Circadian rhythm of photoaccumulation in Paramecium bursaria. J Biol Rhythms, 4(4), 405-15, 1989.
Nicolas, MT, Nicolas, G, Johnson, CH, Bassot, JM, Hastings, JW. Characterization of the bioluminescent organelles in Gonyaulax polyedra (dinoflagellates) after fast-freeze fixation and antiluciferase immunogold staining. J Cell Biol, 105(2), 723-35, 1987.
Olesiak, W, Ungar, A, Johnson, CH, Hastings, JW. Are protein synthesis inhibition and phase shifting of the circadian clock in Gonyaulax correlated. J Biol Rhythms, 2(2), 121-38, 1987.
Johnson, C. H., and J. W. Hastings. The elusive mechanism of circadian clocks. American Scientist 74: 29-36, 1986.
Dube, F., T. Schmidt, C. H. Johnson, and D. Epel. The hierarchy of requirements for an elevated intracellular pH during early development of sea urchin embryos. CELL 40: 657-666, 1985.
Johnson, CH, Inou??, S, Flint, A, Hastings, JW. Compartmentalization of algal bioluminescence: autofluorescence of bioluminescent particles in the dinoflagellate Gonyaulax as studied with image-intensified video microscopy and flow cytometry. J Cell Biol, 100(5), 1435-46, 1985.
Nicolas, MT, Johnson, CH, Bassot, JM, Hastings, JW. Immunogold labeling of organelles in the bioluminescent dinoflagellate Gonyaulax polyedra with anti-luciferase antibody. Cell Biol Int Rep, 9(9), 797-802, 1985.
Johnson, C. H., J. F. Roeber, and J. W. Hastings. Circadian changes of enzyme concentration account for rhythm of enzyme activity in Gonyaulax. Science 223: 1428-1430, 1984.
Johnson, C. H. Changes of intracellular pH are not correlated with the circadian rhythm of Neurospora. Plant Physiol. 72: 129-133, 1983.
One Postdoctoral Position is available January 1, 2013:
Innovative Luminescence Assay for Synaptic Activity, [Ca++], and pH: My laboratory has developed a new technique for monitoring protein-protein interactions (Bioluminescence Resonance Energy Transfer, or BRET). This technique has significant advantages over two-hybrid screens or FRET methods. We developed this technique for assessing interactions among circadian clock proteins (i.e., biological clock proteins) in bacteria (PNAS 96: 151-156, 1998) and have adapted it to imaging in mammalian cells and plants (PNAS 104: 10264-10269, 2007). We have developed a BRET reporter for pH (PLoS ONE 7: e43072, 2012) and BRET reporters for [Ca++] are under development. The current position is to further develop this state-of-the art technique, and apply it as a non-invasive monitor of neural synaptic activity. Experience with imaging and standard molecular genetic techniques is desirable.
There are excellent facilities and collaborations available within the Vanderbilt University system, including other laboratories that study circadian clocks & sleep (e.g., the labs of Doug McMahon, Terry Page, and Beth Malow) and/or that are developing advanced imaging techniques (e.g., David Piston). Nashville is an exciting city with a low cost of living and many artistic opportunities (especially music) as well as close proximity to nature. For more information about my laboratory, see our website: http://www.cas.vanderbilt.edu/johnsonlab/. Interested applicants should contact Dr. Carl Johnson at: firstname.lastname@example.org.