Multiple levels of post-transcriptional control of expression of the poly (A)-binding Protein

Regulating gene expression at the post transcriptional level allows cells to respond quickly to external conditions without remodeling the genome. This approach is advantageous for responding to growth conditions and various cellular stresses. Control of mRNA translation and stability, at the global, as well as at a specific mRNA level are important aspects of post transcriptional regulation of gene expression. Here we have discussed some general features of these two types of post transcriptional control, and reviewed our work on the translational control of poly (A)-binding protein (PABP) expression as a model of translational control of a specific mRNA. PABP itself is an important regulator of mRNA translation and stability; therefore, its own expression is tightly regulated to modulate overall protein synthesis according to growth conditions. A terminal oligopyrimidine tract and an A rich region at the 5́ UTR of PABP mRNA, control its translation in positive and negative manners respectively according to growth conditions.