1Biochemistry 201 Regulation of Translation

A key to the understanding of normal growth and development of eukaryotic cells is the elucidation of the mechanisms by which gene expression is controlled. Much research has concentrated on the regulation of gene expression at the level of messenger RNA (mRNA) formation. It has been observed that the half-lives of most eukaryotic mRNA molecules are measured in hours or days, suggesting that, when a rapid biological response of the mammalian cell is required, regulation of gene expression may occur at the level of translation or subsequent to translation. In fact, examples of translational control are being reported with increasing frequency. Translational control has been reported to be mediated by several classes of mechanism including (1) mRNA decay, (2) cytoplasmic polyadenylation of mRNAs, (3) mRNA localization, (4) structures in mRNAs, (5) modification of translation factors and (6) alterations in the actual mechanisms of initiation of translation. 1. mRNA deca