Vesicular Protein Sorting in the Secretory and Endocytic pathway - Cellular Communication & Lysosome Biogenesis
Vesicular protein transport in the secretory and endocytic pathway is facilitated by cytoplasmic proteins called adaptors, which bind specifically to membranes and to the cytoplasmic tails of cargo proteins. They recruit a number of cytoplasmic proteins to the site of transport vesicle formation. There is a family of four homologous heterotetrameric adaptor-protein complexes: AP-1, AP-2, AP-3 and AP-4. All are ubiquitously expressed in higher eukaryotes and in addition tissue specific isoforms exist. Their precise functions in regulating protein sorting, transport vesicle formation and vesicular trafficking is poorly understood.
We are focusing on the AP-1 adaptor-protein complex, which forms the largest family of AP-complexes. It is required for protein sorting between the trans-Golgi Network and endosomes, which also influences sorting to the plasma membrane. We are using mouse ‘knock-out’ models to study their tissue specific functions. Mouse derived cell lines are established to characterize the deficiencies on a molecular level.