Cutting Edge Seminar - Dr. Alex Webb
Date:
Monday, February 22, 2010 15:00 - 16:00
Duration:
1 Hour
Categories:
Email
Contact info
Maria Eriksson
Title: Systems Analysis of Circadian Signalling
Dr. Alex Webb, Department of Plant Sciences, University of Cambridge
Place: KB3A9, KBC
Abstract
The plant circadian clock regulates many aspects of plant growth and development and provides competitive advantage (Dodd et al. 2005). This is achieved in part by the circadian oscillator regulating the transcription of up to 30% of the Arabidopsis genome. Our research focuses on the circadian modulation of signalling networks. We use physiological, modelling, reverse genetic and bioinformatic tools to determine the role of oscillations of cytosolic free Ca2+ [Ca2+]cyt in the circadian signalling network. I will describe new evidence which suggests that circadian oscillations of [Ca2+]cyt driven by cyclic adenosine diphosphate ribose (cADPR) are sensed by calmodulin-like proteins to regulate circadian oscillator function (Dodd et al., 2007 and Gardner et al., in preparation). We have used linear systems modelling to describe the circadian regulation of [Ca2+]cyt and also 3503 circadian genes. Simulations within these models and testing of hypotheses generated by the models provide insight into the nature and function of the network connections in the circadian signalling pathway. Our data suggest that dual regulation of [Ca2+]cyt by both the circadian oscillator and light participates in circadian oscillator function, possibly as part of loop comprising ADPR cyclase, cADPR and Ca2+. Our systems analyses identify that the circadian oscillator alone might not be sufficient for correct biological timing.
References
Dodd, A.N., Gardner, M.J., Hotta, C.T., Hubbard, K.E., Dalchau, N., Love, J., Assie, J.M., Robertson, F.C., Kyed Jakobsen, M., Gonçalves, J., Sanders D. and Webb A.A.R. (2007) A cADPR-based feedback loop modulates the Arabidopsis circadian clock. Science 318, 1789 -1792.
Dodd, A.N., Salathia, N., Hall, A., Kévei, E., Tóth, R., Nagy, F., Hibberd, J.M., Millar, A.J. and Webb, A.A.R. (2005) Plant circadian clocks improve growth, competitive advantage and survival. Science 309, 630 – 633.
Dr. Alex Webb, Department of Plant Sciences, University of Cambridge
Place: KB3A9, KBC
Abstract
The plant circadian clock regulates many aspects of plant growth and development and provides competitive advantage (Dodd et al. 2005). This is achieved in part by the circadian oscillator regulating the transcription of up to 30% of the Arabidopsis genome. Our research focuses on the circadian modulation of signalling networks. We use physiological, modelling, reverse genetic and bioinformatic tools to determine the role of oscillations of cytosolic free Ca2+ [Ca2+]cyt in the circadian signalling network. I will describe new evidence which suggests that circadian oscillations of [Ca2+]cyt driven by cyclic adenosine diphosphate ribose (cADPR) are sensed by calmodulin-like proteins to regulate circadian oscillator function (Dodd et al., 2007 and Gardner et al., in preparation). We have used linear systems modelling to describe the circadian regulation of [Ca2+]cyt and also 3503 circadian genes. Simulations within these models and testing of hypotheses generated by the models provide insight into the nature and function of the network connections in the circadian signalling pathway. Our data suggest that dual regulation of [Ca2+]cyt by both the circadian oscillator and light participates in circadian oscillator function, possibly as part of loop comprising ADPR cyclase, cADPR and Ca2+. Our systems analyses identify that the circadian oscillator alone might not be sufficient for correct biological timing.
References
Dodd, A.N., Gardner, M.J., Hotta, C.T., Hubbard, K.E., Dalchau, N., Love, J., Assie, J.M., Robertson, F.C., Kyed Jakobsen, M., Gonçalves, J., Sanders D. and Webb A.A.R. (2007) A cADPR-based feedback loop modulates the Arabidopsis circadian clock. Science 318, 1789 -1792.
Dodd, A.N., Salathia, N., Hall, A., Kévei, E., Tóth, R., Nagy, F., Hibberd, J.M., Millar, A.J. and Webb, A.A.R. (2005) Plant circadian clocks improve growth, competitive advantage and survival. Science 309, 630 – 633.