ABSTRACT
INTRODUCTION There has been an extensive research effort to develop vectors that efficiently introduce foreign genes into cells. These efforts have lead to the development of a number of viral and non-viral vectors. Following cellular uptake, genes must be transported to the nucleus for efficient gene expression. Among many other factors, it is believed that efficient gene expression depends on the type of promoters used. After transcription, the mRNA must undergo extensive processing before becoming functional, i.e., 5' capping, splicing, and 3' end processing i.e., cleavage and polyadenylation. Once processing is complete, the mature mRNA is exported into the cytoplasm where it undergoes translation. Recently, significant progress has been made in our understanding of mRNA export mechanisms. It is now clear that efficient gene expression will require the optimization of the transgene mRNA export.
