Autoregulation - Autoregulation of Genes

Autoregulation of Genes

This is so-called "steady-state system". An example is a system in which a protein a that is a product of gene A "positively regulates it's own production by binding to a regulatory element of the gene coding for it", and the protein gets used or lost at a rate that increases as its concentration increases. This feedback loop creates two possible states "on" and "off". If an outside factor makes the concentration of a increase to some threshold level, the production of protein a is "on", i.e. a will maintain its own concentration at a certain level, until some other stimulus will lower it down below the threshold level, when concentration of a will be insufficient to make gene A express at the rate that would overcome the loss or use of the protein a. This state ("on" or "off") gets inherited after cell division, since the concentration of protein a usually remains the same after mitosis. However, the state can be easily disrupted by outside factors.