Research objectives and content Clathrin-coated vesicle formation leads to the receptor-mediated endocytosis of extracellular macromolecules. The mechanism which regulates the formation of such vesicles is poorly understood. Clathrin, adaptors, ATP and cytosol are all required for the formation of these vesicles. One of the cytosolic components required for coated pit invagination has been identified as rab5-rabGDI, a component previously demonstrated to be important for membrane dynamics at later stages of the endocytic pathway. The processes of transport vesicle formation and subsequent fusion therefore appear to be linked. The aim of this project is to further define the role of rab5 in clathrin-coated pit formation using biochemical and morphological approaches. These studies should yield valuable information, not only about the mechanism of clathrin coated pit assembly but may also have implications for other vesicle trafficking pathways. Training content (objective, benefit and expected impact) Only limited data are available on the regulation of clathrin-coated vesicle formation . This project will lead to a better understanding of this mechanism in elucidating the function of rab5 and interacting proteins. This will ultimately help propose a model for the formation of the clathrin-coated vesicles. This project will provide training in addressing essential question in cell biology using multidisciplinary approach. Links with industry / industrial relevance (22) The research carried out in the host laboratory is basic research into an essential cellular mechanism. At the moment there are no links with industry.