Oscillations are an important type of
cell signaling
In biology, cell signaling (cell signalling in British English) is the Biological process, process by which a Cell (biology), cell interacts with itself, other cells, and the environment. Cell signaling is a fundamental property of all Cell (biol ...
characterized by the periodic change of the system in time.
[Kruse & Jülicher. Oscillations in Biology. 2005] Oscillations can take place in a
biological system
A biological system is a complex Biological network inference, network which connects several biologically relevant entities. Biological organization spans several scales and are determined based different structures depending on what the system is ...
in a multitude of ways. Positive
feedback loops, on their own or in combination with
negative feedback
Negative feedback (or balancing feedback) occurs when some function (Mathematics), function of the output of a system, process, or mechanism is feedback, fed back in a manner that tends to reduce the fluctuations in the output, whether caused ...
are a common feature of oscillating biological systems.
[Kholodenko. Cell-signaling dynamics in time and space. 2006]
Examples
Genetic oscillation
One of the most common forms of biological oscillation is
genetic oscillation, which can take place when a
transcription factor
In molecular biology, a transcription factor (TF) (or sequence-specific DNA-binding factor) is a protein that controls the rate of transcription (genetics), transcription of genetics, genetic information from DNA to messenger RNA, by binding t ...
binds and represses its own
promoter. This type of regulatory system is able to successfully describe the
NFkB-IkB and
p53-Mdm52 biological oscillating systems.
Relaxation oscillations
Relaxation oscillation takes place in the context of a
bi-stable system. It is characterized by the periodic switching between two stable states.
References
{{reflist
Cell signaling