In cellular biology, P-bodies, or processing bodies, are distinct foci formed by phase separation within the cytoplasm of a eukaryotic cell consisting of many enzymes involved in mRNA turnover.
[1] P-bodies are highly conserved structures and have been observed in somatic cells originating from vertebrates and invertebrates, plants and yeast.
[5] P-bodies were originally proposed to be the sites of mRNA degradation in the cell and involved in decapping and digestion of mRNAs earmarked for destruction.
Their importance was recognized after experimental evidence was obtained pointing to P-bodies as the sites of mRNA degradation in the cell.
During this time, many descriptive names were used also to identify the processing bodies, including "GW-bodies" and "decapping-bodies"; however "P-bodies" was the term chosen and is now widely used and accepted in the scientific literature.
Another ambiguous point to be addressed is whether the proteins that localize to P-bodies are actively functioning in the miRNA gene silencing process or whether they are merely on standby.
[5] Notably this work provided the most compelling evidence up to this date that P-bodies might not be the sites of degradation in the cell and instead used for storage of translationally repressed mRNA.
[9] In 2018, Youn et al. took a proximity labeling approach called BioID to identify and predict the processing body proteome.