Translocation of mRNAs by molecular motors: Think complex?

In recent years, closer inspection of the dynamics of cytoplasmic mRNA transport processes has shed new light on the mechanisms by which transcripts are recognized by motor complexes and deposited at the correct site. Several studies have highlighted the significance of the motile properties of motor complexes in differential transcript localization. In yeast, mRNA cargoes may stimulate either the movement or anchorage of actin-based motors. In higher eukaryotes, emerging evidence suggests that mRNA cargoes can control their sorting by regulating the motility of motor complexes or their choice of subsets of cytoskeletal tracks. The transport machinery that is utilized by differentially localizing mRNAs appears to share some common motors and regulatory factors. A major challenge for the future is therefore to understand how motor complexes decode the information in mRNA sequences. (C) 2007 Elsevier Ltd. All rights reserved.