Is DNA repair controlled by a biological logic circuit?

Abstract

The possible utilization of biological logic circuit(s) in the integration and regulation of DNA repair is discussed. The author believes this mode of regulation likely applies to many other areas of cell biology; however, there are currently more experimental data to support its involvement in the control of DNA repair. Sequential logic processes always require a clock to orchestrate the orderly processing of events. In the proposed hypothesis, the pulses in the expression of p53 serve this function. Given the many advantages of logic type control, one would expect that in the course of ~ 3 billion years of evolution, where single cell life forms were likely the only forms of life, a biological logic type control system would have evolved to control at least some biological processes. Several other required components in addition to the 'clock' have been identified, such as; a method to temporarily inactivate repair processes when they are not required (e.g. the reversible inactivation of MGMT, a suicide repair protein, by phosphorylation); this prevents complex DNA repair systems with potentially overlapping repair functions from interfering with each other.