title: Growth-related model of the GAL system in Saccharomyces cerevisiae predicts behaviour of several mutant strains.
abstract: The genetic regulatory network responds dynamically to perturbations in the intracellular and extracellular environments of an organism. The GAL system in the yeast Saccharomyces cerevisiae has evolved to utilise galactose as an alternative carbon and energy source, in the absence of glucose in the environment. This work contains a modified dynamic model for GAL system in S. cerevisiae, which includes a novel mechanism for Gal3p activation upon induction with galactose. The modification enables the model to simulate the experimental observation that in absence of galactose, oversynthesis of Gal3p can also induce the GAL system. Subsequently, the model is related to growth on galactose and glucose in a structured manner. The growth-related models are validated with experimental data for growth on individual substrates as well as mixed substrates. Finally, the model is tested for its prediction of a variety of known mutant behaviours. The exercise shows that the authors' model with a single set of parameters is able to capture the rich behaviour of the GAL system in S. cerevisiae. [Includes supplementary material].
authors.affiliation: Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai, India.
authors.forename: V R
authors.initials: VR
authors.lastname: Pannala
authors.forename: S J
authors.initials: SJ
authors.lastname: Hazarika
authors.forename: P J
authors.initials: PJ
authors.lastname: Bhat
authors.forename: S
authors.initials: S
authors.lastname: Bhartiya
authors.forename: K V
authors.initials: KV
authors.lastname: Venkatesh
mesh_terms: D049109:Cell Proliferation / Q000187:drug effects; D003470:Culture Media / Q000737:chemistry; D005690:Galactose / Q000494:pharmacology; D017353:Gene Deletion; D015966:Gene Expression Regulation, Fungal / Q000187:drug effects; D053263:Gene Regulatory Networks / Q000187:drug effects; D005947:Glucose / Q000494:pharmacology; D008954:Models, Biological; D009004:Monosaccharide Transport Proteins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D012441:Saccharomyces cerevisiae / Q000166:cytology* / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D003470:Culture Media; C106901:GAL2 protein, S cerevisiae; D009004:Monosaccharide Transport Proteins; D029701:Saccharomyces cerevisiae Proteins; D005947:Glucose; D005690:Galactose