Evolutionarily stable and fragilemodules of yeast biochemical network

QR Microbiology;QA75 Electronic computers. Computer science

Santra, Tapesh ; Girolami, Mark

University:University of Glasgow

Department:School of Mathematics and Statistics

关键词: Molecular Evolution, Yeast, Systems biology, Protein interaction;   

Others  :  http://theses.gla.ac.uk/2644/1/2011santraPhd.pdf

来源: University of Glasgow

【 摘 要 】

Gene and protein interaction networks have evolved to preciselyspecify cell fates and functions. Here, we analysewhether the architecture of these networks affects evolvability.We find evidence to suggest that in yeast these networks aremainly acyclic, and that evolutionary changes in these parts donot affect their global dynamic properties. In contrast, feedbackloops strongly influence dynamic behaviour and are oftenevolutionarily conserved. Feedback loops are often found toreside in a clustered manner by means of coupling and nestingwith each other in the molecular interaction network of yeast.In these clusters some feedback mechanisms are biologicallyvital for the operation of the module and some provide auxiliaryfunctional assistance. We find that the biologically vitalfeedback mechanisms are highly conserved in both transcriptionregulation and protein interaction network of yeast. Inparticular, long feedback loops and oscillating modules in proteininteraction networks are found to be biologically vital andhence highly conserved. These data suggest that biochemicalnetworks evolve differentially depending on their structurewith acyclic parts being permissive to evolution while cyclicparts tend to be conserved.