Reconstitution of a cellular transport process
In eukaryotic cells, vesicles enable dynamic transport processes that connect different kinds of membrane-enclosed compartments or organelles. Beginning with the formation of transport vesicles in the donor compartment, separation from the donor membrane is achieved via motor proteins like actin and myosin. Such transport processes are key to normal cellular function. Recently, research has uncovered an interaction between Rab6 (a Golgi-associated RabGTPase) and nonmusle Myosin II A (nmMyoIIA) in the Rab6 transport process. nmMyoIIA was linked to the fission, or separation, of Rab6 transport carriers at the trans-Golgi network. Scientists of the project MYOII-DRIVEN FISSION (Reconstitution of myosin IIA-driven membrane fission in vitro) successfully developed an in vitro system to mimic the MyoIIA-driven fission process. For this purpose, they used the purified components (MyoIIA, Rab6 and actin) with giant unilamellar vesicles (GUVs) and optical tweezers. Their aim was to obtain deeper insight into the factors involved in the regulation of fission in intracellular transport. The researchers were able to recruit several Rab6 effectors to the GUVs in a Rab6-GTP dependent manner. They also detected Rab6A, nmMyoIIA and actin on isolated Golgi membranes and managed to pull nanotubes using optical tweezers from these membranes. Any perturbations in intracellular transport can cause severe pathologies such as Parkinson's and Huntingdon's disease. In particular, Rab6 dysfunction has been associated with many disease states ranging from infectious diseases to cancer. Project outcomes could eventually lead to the design of personalised drug design to restore good health.
Keywords
Cellular, reconstitution, intracellular transport, Myosin II A, Rab6, fission, GUV, optical tweezer
