Mex67p

Mex67p is a protein found in the yeast Saccharomyces cerevisiae. It plays a crucial role in the export of messenger RNA (mRNA) from the nucleus to the cytoplasm. This process is essential for gene expression, as mRNA carries the genetic information transcribed from DNA to the ribosomes, where proteins are synthesized.

Mex67p is a member of the Nxf family of nuclear export factors, which are conserved across eukaryotes. It functions as an RNA-binding protein and interacts with other components of the mRNA export machinery, including the nuclear pore complex (NPC) and other export factors like Mtr2p. These interactions facilitate the translocation of mRNA through the NPC, a large protein channel that regulates the passage of molecules between the nucleus and the cytoplasm.

The export of mRNA is a tightly regulated process, and Mex67p is a key player in ensuring its fidelity. It binds to mature mRNA molecules and guides them to the NPC, where they are then shuttled into the cytoplasm. This mechanism prevents the export of unprocessed or aberrant RNA molecules, thereby maintaining the integrity of the transcriptome. Studies have shown that mutations in Mex67p can lead to defects in mRNA export, resulting in impaired protein synthesis and cellular dysfunction. Its importance in this fundamental cellular process highlights its significance in yeast biology.