Utilisateur:Mohamedtaha1984/Brouillon

Mammalian UVC Stress Granules (mUVC-SGs)

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A major advance in RNA biology was the characterization of classical Stress Granules (SGs) ([1]). Following a stress such as heat, arsenite and oxydative treatments, mRNAs is released from the translational machinery and is sequestred into transcriptionally incompetent granules containing repressed mRNAs. RNA stress granules induced by UV behave differently than SGs. Exposure of mammalian cells in culture to UVC induces the formation of discrete cytoplasmic RNA granules termed “mammalian UVC Stress Granules (mUVC-SGs). The presence of these granules seems to occur independently of importantly, does not correlate with major translation inhibition. Concomitant with the accumulation of mUVC-SGs in the cytoplasm, cells enter a quiescent state, as they are arrested in G1 phase of the cell cycle. This blockage persists as long as granules are present.

Proposed functions of mUVC-SGs

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The purpose of mUVC-SGs, that UVC induces the recruitment of a restricted subset of mRNAs and associated proteins from active polyribosomes to be stored in a repressed form. Since their formation correlates with cell cycle arrest, it is tempting to speculate that mUVC-SGs may sequester mRNAs directing the synthesis of cell cycle regulator proteins, thereby preventing their expression and thus cell proliferation.


  1. Kedersha NL, Gupta M, Li W, Miller I, Anderson P (1999) RNA-binding proteins TIA-1 and TIAR link the phosphorylation of eIF-2aplha to the assembly of mammalian stress granules. J Cell Biol 147: 1431-1442.