title: Quantification of noise in bifunctionality-induced post-translational modification.
abstract: We present a generic analytical scheme for the quantification of fluctuations due to bifunctionality-induced signal transduction within the members of a bacterial two-component system. The proposed model takes into account post-translational modifications in terms of elementary phosphotransfer kinetics. Sources of fluctuations due to autophosphorylation, kinase, and phosphatase activity of the sensor kinase have been considered in the model via Langevin equations, which are then solved within the framework of linear noise approximation. The resultant analytical expression of phosphorylated response regulators are then used to quantify the noise profile of biologically motivated single and branched pathways. Enhancement and reduction of noise in terms of extra phosphate outflux and influx, respectively, have been analyzed for the branched system. Furthermore, the role of fluctuations of the network output in the regulation of a promoter with random activation-deactivation dynamics has been analyzed.
authors.affiliation: Department of Chemistry, University of Calcutta, 92 A P C Road, Kolkata 700 009, India.
authors.forename: Alok Kumar
authors.initials: AK
authors.lastname: Maity
authors.forename: Arnab
authors.initials: A
authors.lastname: Bandyopadhyay
authors.forename: Sudip
authors.initials: S
authors.lastname: Chattopadhyay
authors.forename: Jyotipratim Ray
authors.initials: JR
authors.lastname: Chaudhuri
authors.forename: Ralf
authors.initials: R
authors.lastname: Metzler
authors.forename: Pinaki
authors.initials: P
authors.lastname: Chaudhury
authors.forename: Suman K
authors.initials: SK
authors.lastname: Banik
mesh_terms: D007700:Kinetics; D008954:Models, Biological; D011499:Protein Processing, Post-Translational; D015398:Signal Transduction