Article

P-Bodies React to Stress and Nonsense

Department of Biochemistry and Molecular Biology, The University of Texas M.D. Anderson Cancer Center, Houston, 77030, USA.
Cell (Impact Factor: 33.12). 07/2006; 125(6):1036-8. DOI: 10.1016/j.cell.2006.06.003
Source: PubMed

ABSTRACT P-bodies are specialized cytoplasmic compartments where translational repression and mRNA turnover may occur. Findings in this issue of Cell provide evidence that P-bodies are sites of "mRNA purgatory." Bhattacharyya et al. (2006) reveal that normal mRNA can be released from P-bodies and translated into protein in response to stress. Meanwhile, Sheth and Parker (2006) report that aberrant mRNAs are targeted to P-bodies to undergo rapid decay.

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    • "P-bodies contain translation repressors, mRNA degradation enzymes, and cofactors such as decapping holoenzyme and XRN1 exoribonuclease (Franks and Lykke-Andersen, 2008; Parker and Sheth, 2007), while SGs contain translation initiation machinery components (Anderson and Kedersha, 2008). Contrary to SGs, a limited number of p-bodies can be detected in cells under normal conditions , but both granule types increase in size and number upon stress-limiting translation initiation, such as heat (Bruno and Wilkinson, 2006; Weber et al., 2008). Although the mRNA decay machinery concentrates in p-bodies, it is still debated whether they are actual sites of mRNA decapping and degradation . "
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    • "Distinct classes of ribonucleoprotein (RNP) granules appear to function in specific aspects of RNA metabolism (Anderson and Kedersha, 2006). Cytoplasmic processing bodies, termed P bodies, are involved in mRNA degradation, nonsense-mediated RNA decay (NMD), siRNA-and micro- RNA (miRNA)-mediated gene silencing in mammalian cells (Sheth and Parker, 2003; Cougot et al., 2004; Jakymiw et al., 2005; Liu et al., 2005a, 2005b; Sen and Blau, 2005; Bruno and Wilkinson, 2006; Parker and Sheth, 2007). Consistently, P bodies contain components involved in 5' to 3' mRNA degradation, including the decapping complex DCAP1/ DCAP2, decapping coactivators (e.g. "
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    • "They consist of translation repressors, mRNA decapping proteins, and a 5–3 exonuclease. P-bodies are particularly important for translational repression during cellular stress, when repression of many mRNAs is crucial to halt growth and enhance cell survival (Bruno and Wilkinson, 2006; Sheth and Parker, 2006; Buchan et al., 2008; Gallo et al., 2008; Nissan and Parker, 2008). P-bodies are critical for the formation of stress granules, which are comprised of aggregates of untranslating mRNAs, a subset of translation initiation factors, the 40S ribosome subunit, and poly(A)-binding proteins, such as Pab1 and Pub1 (Anderson and Kedersha, 2008, 2009; Buchan et al., 2008). "
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