RNP transport in cell biology: the long and winding road

- RNA localization is highly conserved throughout evolution.
- mRNPs regulate every step of the journey from birth to death.
- mRNPs movement is a combination of diffusion and directed transport.
- RNA localization is coupled to translational control for local protein synthesis.
- mRNAs can be simultaneously transported and actively translated in neurons.

Regulation of gene expression is key determinant to cell structure and function. RNA localization, where specific mRNAs are transported to subcellular regions and then translated, is highly conserved in eukaryotes ranging from yeast to extremely specialized and polarized cells such as neurons. Messenger RNA and associated proteins (mRNP) move from the site of transcription in the nucleus to their final destination in the cytoplasm both passively through diffusion and actively via directed transport. Dysfunction of RNA localization, transport and translation machinery can lead to pathology. Single-molecule live-cell imaging techniques have revealed unique features of this journey with unprecedented resolution. In this review, we highlight key recent findings that have been made using these approaches and possible implications for spatial control of gene function.