Report of Taikichiro Mori Memorial Research Fund 2009



Research Project:

Cellular dynamics

Project Name:

Self-organisation of amino acid regulation in yeast


Kalesh Sasidharan, D3


Institute for Advanced Biosciences, Graduate school of media and governance, Keio University




My research is based on experimental and computation biology. The Mori grant has given me a good opportunity to improvise my research by equipping the lab with necessary equipments. I have purchased several computer peripherals, which are necessary for the data storage and data acquisition. Apart of that, I have upgraded my computers and storage devices to store and process huge amount of data files. My research theme, progress and final goals are given below.


Research Project Abstract


When Saccharomyces cerevisiae are grown continuously, respiration autosynchronises resulting in stable oscillatory dynamics, where small molecules mediate communication [1]. Transcriptome-wide and metabolome-wide studies indicate that the oscillation functions to temporally separate catabolic and anabolic processes. Consistent with this, the production of amino acids have distinct phase relationships with the oscillation cycle where amino acids are produced in conjunction with S-phase [1]. In addition, oscillation is highly sensitive to amino acid and Rapamycin perturbation [1]. These data indicate a role for the master amino acid regulator Gcn4p in the regulation of oscillatory dynamics, where the Gcn4p is activated by non-aminoacylated tRNAs [2]. Therefore we explore the role of non-aminoacylated tRNAs in oscillatory regulation by constructing a regulatory model of amino acid regulation then testing this experimentally to provide a mechanistic understanding of amino acid feedback on gene regulation. We will also discuss the context of our work in the emergence of coherent behavior in biochemical networks.


Full Report (PDF format)



1. Douglas B Murray, Manfred Beckmann, and Hiroaki Kitano. Regulation of yeast oscillatory dynamics. Proc Natl Acad Sci U S A, 104(7):2241_2246, Feb 2007.

2. Alan G Hinnebusch. Translational regulation of gcn4 and the general amino acid control of yeast. Annu Rev Microbiol, 59:407_450, 2005.