Small RNA biology is systems biology.
During the last decade small regulatory RNA (srRNA) emerged as central players in the regulation of gene expression in all kingdoms of life. Multiple pathways for srRNA biogenesis and diverse mechanisms of gene regulation may indicate that srRNA regulation evolved independently multiple times. However, small RNA pathways share numerous properties, including the ability of a single srRNA to regulate multiple targets. Some of the mechanisms of gene regulation by srRNAs have significant effect on the abundance of free srRNAs that are ready to interact with new targets. This results in indirect interactions among seemingly unrelated genes, as well as in a crosstalk between different srRNA pathways. Here we briefly review and compare the major srRNA pathways, and argue that the impact of srRNA is always at the system level. We demonstrate how a simple mathematical model can ease the discussion of governing principles. To demonstrate these points we review a few examples from bacteria and animals.
Department of Physics, FAS Center for Systems Biology, Harvard University, Cambridge MA 02138, USA.
Daniel
D
Jost
Andrzej
A
Nowojewski
Erel
E
Levine
D000818:Animals; D001419:Bacteria / Q000235:genetics; D035683:MicroRNAs / Q000378:metabolism; D018384:Oxidative Stress; D034741:RNA, Small Interfering / Q000378:metabolism; D058727:RNA, Small Untranslated / Q000378:metabolism*; D049490:Systems Biology
D035683:MicroRNAs; D034741:RNA, Small Interfering; D058727:RNA, Small Untranslated