One of the best-studied properties of the MAPK system is its ability to convert graded input stimulus to switch-like all-or-none responses.
Also, course grades, input from high school mathematics and science teachers, and the results of statewide standardized tests will be used to establish benchmarks and to measure students' progress.
In this context, one obvious possibility is that cellular responses are directly proportional to the stimulus, that is, graded input elicits graded output.
Recent experimental work has shown that the mitogen-activated protein (MAP) kinase cascade can convert graded inputs into switch-like outputs.
Cell signaling systems that contain positive-feedback loops or double-negative feedback loops can, in principle, convert graded inputs into switch-like, irreversible responses.
Positive feedback is a ubiquitous signal transduction motif that allows systems to convert graded inputs into decisive, all-or-none outputs.
These findings indicate that MAPKK-1* phosphorylates p42 MAPK by a two-collision, distributive mechanism rather than a single-collision, processive mechanism, and provide a mechanistic basis for understanding how MAP kinase can convert graded inputs into switch-like outputs.
However, stochastic molecular processes have graded input-output functions, thus, bioengineers must select those with desirable characteristics and refine their transfer functions to build logic gates with digital-like switching behaviour.
A positive-feedback loop or double-negative feedback loops can convert graded inputs into switch-like, irreversible responses [ 51].
To understand the mechanism of bimodality observed by Birtwistle et al. [ 1], we will illustrate graded input-output response curves of the type that share their observed typical response patterns.
