Pathological circadian rhythm states driven by CK2 and noise

Circadian rhythm maintains sleep-wake cycle in living systems. Disruption of this rhythm may cause diseases. We propose an extended Drosophila circadian rhythm model incorporating cross-talk of CK2 with Per protein. We studied the model using stochastic simulation algorithm, and the behavior of the amplitude, time period and permutation entropy us identify three distinct circadian states namely, active, weak activity, active, weak activity and rhythmic death all driven by CK2. These states may correspond to distinct pathological cellular states of the living system. Noise, an important factor, has ability to switch normal circadian rhythm to any of the three aforementioned circadian states. Fluctuations in systems size, can help us in deterning the extent of noise present. We also highlighted that disruption in circadian rhythm may lead to various diseases including cancer. We present various cellular pathways driven by per mutant genes and their pathological states.\n\nStatement of significanceCircadian rhythm, which is one of the most important biological rhythm, regulates and intervenes various cellular processes. Significant changes in the rhythmic dynamics may lead to pathological states which may trigger various diseases. In this work, the impact of CK2 via per gene mutants on rhythmic dynamics is investigated, and found three distinct states, namely, active, weak activity and rhythmic death driven by CK2 which may correspond to various cellular states. Noise due to intrinsic random molecular events and cellular size variability is found to have the capability of regulating and controlling rhythmic properties, and can trigger to the three rhythmic states. We then listed various possible pathways which are regulated by per gene mutants and corresponding various possible pathological states.