GW bodies, microRNAs and the cell cycle.

GW bodies (GWBs) are cytoplasmic foci initially identified through the use of an autoimmune serum targeting the marker protein, GW182. GWBs were first considered as both storage centers for a specific subset of mRNAs and degradation sites for mRNAs. Interestingly, they are known to vary in size and number throughout the cell cycle and are largest in size and most abundant in number during the late S and G2 phases. Recent studies have linked RNA interference to GWBs, in that disruption or disassembly of GWBs was demonstrated to impair siRNA and miRNA silencing activity. As miRNAs are implicated in the regulation of cell cycle progression and cell proliferation, it is very likely that GWBs, the critical intracellular structures for miRNA function, may very well be also linked to this cellular process.