Gene Expression is a fundamental process of any living cell. In eukaryotic cells, the genetic information is transcribed into mRNA by RNA polymerase II. Already cotranscriptionally the mRNA is processed (capped, spliced, and polyadenylated). In addition, the mRNA is packaged into a mature mRNP. Since nucleoplasm and cytoplasm are separated by the nuclear envelope, the mRNP needs to be exported through the nuclear pore complexes (NPCs) into the cytoplasm. Here, the information encoded in the mRNA is translated into a polypeptide chain by the ribosomes.
These events do not occur consecutively, but are tightly interconnected. This coupling guarantees an efficient and accurate expression of the genetic information and thus provides a quality control mechanism for this fundamental cellular process.