Biology Reference
In-Depth Information
CHAPTER NINE
Biological Robustness and the Role
of MicroRNAs: A Network Perspective
Nicol´sPel´ez
*
,
†
,
‡
and
Richard W. Carthew
†
,
‡
Contents
1. MicroRNAs and Large-Scale Networks
238
239
1.1. Network hubs and miRNAs
242
1.2. Signal flow and miRNAs
1.3. Network modules and miRNAs
242
245
1.4. How do these properties affect network robustness?
2. MicroRNAs and Circuits
245
246
2.1. Circuits are recurrent patterns in large-scale networks
2.2. Feedback loops and miRNAs
247
250
2.3. Feedforward loops and miRNAs
3. Conclusion
252
Acknowledgments
252
References
253
Abstract
Over the past decade, microRNA molecules have emerged as critical regulators
in the expression and function of animal genomes. This review discusses the
relationship between microRNA-mediated regulation and the robustness of
biochemical networks that contain microRNAs. Most biochemical networks are
robust; they are relatively insensitive to the precise values of reaction constants
and concentrations of molecules acting within the network. MicroRNAs involved
in network robustness may appear to be nonessential under favourable uniform
conditions used in conventional laboratory experiments. However, the function
of these molecules can be revealed under environmental and genetic pert-
urbations. Recent advances have revealed unexpected features of microRNA
organization in networks that help explain their promotion of robustness.
* Interdepartmental Program in Biological Sciences, Northwestern University, Evanston, Illinois, USA
{
Department of Molecular Biosciences, Northwestern University, Evanston, Illinois, USA
{
Chicago Center for Systems Biology, Chicago, Illinois, USA
