Diauxic shift-dependent relocalization of decapping activators Dhh1 and Pat1 to polysomal complexes

Drummond, Sheona P.; Hildyard, John; Firczuk, Helena; Reamtong, Onrapak; Li, Ning; Kannambath, Shichina; Claydon, Amy J.; Beynon, Robert J.; Eyers, Claire E.; McCarthy, John E. G.

Recent years have seen recognition that a diversity of post-transcriptional control mechanisms influences the rate and regulation of eukaryotic gene expression. Yet our understanding of the interplay between the component processes of post-transcriptional gene expression is very limited. A prime example is the relationship between translation and mRNA degradation, which is not only fundamental to the correct functioning of gene expression but also a potential cause of disease if defective. It has been proposed that translational repression, as for example observed under stress conditions, is a key step in promoting mRNA decapping, thus leading to the formation of P bodies (1, 2) . P bodies, like stress granules, are RNA/protein foci that form under certain (mostly stress-related) conditions in eukaryotic cells. P bodies generally contain non-translating mRNAs as well as the mRNA decapping machinery, Lsm1-7, the 5 0 -3 0 exonuclease Xrn1 and other RNA-binding proteins (3) , although the physical nature and degree of heterogeneity of P body populations is unclear.