The law of limiting factor establishes the dependence organism functioning on the environmental conditions. The molecular basis of this adaptation determined with differentional gene's activity. The expression of more than 6000 genes in response to the deficiency in nitrogen, carbon or phosphorus in growth medium has been studied in yeast Saccharomyces cerevisiae. The model of integral yeast cell response on limiting factor was suggested on the basis of this data and the data concerning mechanisms of metabolic pathways regulation. According to this model, phosphoprotein kinase (Tor1p, Tor2p, Snf1p or Pho85p) that regulates corresponding metabolic pathway receives a signal about the limiting factor and become dominated kinase. Dominated kinase regulates activators and repressors proteins of its own metabolic pathway but it is also able to affect the activity of transcription regulators of other metabolic pathways. Proteins could be activators of one set of metabolic pathways and in the same time serve as repressors of others. That allows the regulation of cell metabolism according to the limiting factor. Dominated kinases can be involved in phosphorylation of DNA polymerases and affect the level of spontaneous mutations. Mutations that increase that viability of cells on the background of limiting factor are selected. Thus the relationship between inheritable and non-inheritable variability is not occasional and take place on the genetic level and the limiting factor is the reason for modification and inheritable variabilities.

• PMID: 16212281
• PubMed
• PubTator

Reference Type

Journal Article | Review

Authors

Sambuk EV

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