Pluto Bioinformatics

GSE134660: The Dynamics of Cytoplasmic mRNA Metabolism

Bulk RNA sequencing

For all but a few mRNAs, the dynamics of metabolism are unknown. Here, we developed an experimental and analytical framework for examining these dynamics for mRNAs from thousands of genes. mRNAs of mouse fibroblasts exit the nucleus with diverse intragenic and intergenic poly(A)-tail lengths. Once in the cytoplasm, they have a broad (1000-fold) range of deadenylation rates, which correspond to cytoplasmic lifetimes. Indeed, degradation appears to occur primarily through deadenylation-linked mechanisms, with little contribution from endonucleolytic cleavage or deadenylation-independent decapping. Most mRNA molecules degrade only after their tail lengths fall below 25 nt. Decay rates of short-tailed mRNAs vary broadly (1000-fold) and are more rapid for short-tailed mRNAs that had previously undergone more rapid deadenylation. This coupling helps clear rapidly deadenylated mRNAs, enabling the large range in deadenylation rates to impart a similarly large range in stabilities. SOURCE: Timothy,J,Eisen (teisen@wi.mit.edu) - David Bartel Whitehead Institute for Biomedical Research