A lipid bilayer, called the plasma membrane, surrounds every cell. This protects the cell from the environment and keeps the insides in. Keeping material contained is important for many aspects of biology. Lipid bilayers form organelles and vesicles within the cell to contain specialized components. For example, powerful enzymes recycle old material in the cell. If not contained these enzymes would wreak havoc. To prevent this lysosomes contain the enzymes, protecting the cellular contents. Material from all over the cell can get added to lysosomes.
Vesicles move material from one place to another. Endosomes move material from the plasma membrane. Endosomes either fuze with lysosomes or recycle back to the plasma membrane. The lipid bilayer of an endosome will join with the plasma membrane. The contents of the endosome exit the cell. The endosome can contain even smaller vesicles. Outside the cell we call these vesicles exosomes.
During my PhD I discovered that exosomes can transfer proteins between kidney cells. Wilna Oosthuyzen continued this work by asking what regulates this process. She discovered that vasopressin regulates exosome uptake in collecting duct cells of the kidney.
It is very gratifying when a study builds on work I published earlier, and particularly when executed so well. I was very pleased to be able to contribute.