Moving forward: polarised trafficking in cell migration.

Polarised vesicle trafficking has been suggested to regulate cell migration. Understanding how this takes place has been complicated by the use of disparate assays and cellular models. Although polarised trafficking does occur in cell motility it is not clear which pathways are involved. We propose a model for migrating cells where caveolar endocytosis occurs at the rear of the adherent surface, whereas clathrin-mediated endocytosis takes place in the middle-to-front region of the cell. We also suggest there is evidence to support polarised recycling of internalised cargo to the leading edge of migrating cells. Further research is required to confirm our hypothesis and a systematic evaluation of multiple pathways within individual systems and across different models is needed.