Tracking the transport of E-cadherin to and from the plasma membrane.

The epithelial to mesenchymal transition (EMT) is the breakdown of epithelial cell morphology that gives way to a more mobile, mesenchymal phenotype. Although this process is fundamental to the development of multicellular organisms, it is also a key occurrence in many diseases, including cancers of epithelial origin E-cadherin is a central component of adherens junctions (AJs), which act as structural and signaling hubs in epithelial cells that oppose EMT. The loss of E-cadherin from the plasma membrane is an early indication of EMT and a marker of poor prognosis in many cancers making the trafficking of E-cadherin an area of great interest. Recent work from the authors' laboratory has established the role of type I gamma phosphatidylinositol 4-phosphate 5-kinase (PIPKI gamma) in the trafficking of E-cadherin by studying the surface accessibility of E-cadherin in endocytosis and recycling assays. Additionally, immunofluorescence data demonstrated that cells lacking PIPKI gamma lost E-cadherin at the plasma membrane. The biochemical and microscopic techniques used to investigate the trafficking of E-cadherin are presented herein.