mRNP Transport in Eukaryots: Transport of mRNP Particles in Cytoplasm

After synthesis and processing in the nucleus, mature mRNA penetrates through nuclear pores to cytoplasm. mRNP particles are formed in the nucleus and remodeled in cytoplasm, resulting in association with factors required for mRNP proper functions. In the cytoplasmic compartment, mRNP particles can include proteins participating in nuclear interactions, as well as new factors specific for cytoplasmic mRNA–protein interactions. Functions of newly synthesized mRNAs and their cytoplasmic localization are substantially diverse. Cytoskeletal and motor proteins were shown to participate in delivery of mRNP particles to their localization sites. Several families of motor proteins are known in eukaryotes, and functions of all of them were shown to be coordinated in order to compose machinery for cargo delivery to specific cytoplasmic destinations. Adapter proteins, mediators between mRNP particles and motor proteins, are also required to make this transport system functional. Unlike the well-studied system of the cytoskeletal and motor proteins, our knowledge of how mRNP particles bind motor proteins via adapter ones is still sparse.