ESCRTkomplexek

ESCRTkomplexek, or Endosomal Sorting Complex Required for Transport complexes, are protein machineries crucial for cellular membrane trafficking. These complexes are involved in a variety of essential cellular processes, including the formation of multivesicular bodies (MVBs), the budding of enveloped viruses from cells, and the repair of cellular membranes. There are three main ESCRT complexes, known as ESCRT-0, ESCRT-I, and ESCRT-II, which typically act in a sequential manner. ESCRT-0 is responsible for the initial recognition and binding of ubiquitinated cargo proteins destined for MVBs. It then recruits ESCRT-I, which in turn recruits ESCRT-II. The recruitment of these initial complexes often leads to the deformation of the endosomal membrane. A fourth component, the ESCRT-III complex, plays a more dynamic role. It assembles into spiral filaments on the cytosolic face of the endosomal membrane, constricting the neck of the budding vesicle. Finally, the AAA+ ATPase Vps4 disassembles the ESCRT-III filaments, releasing the machinery and completing the budding process. Mutations in ESCRT components are linked to various diseases, including developmental disorders and cancer, highlighting their fundamental importance in cellular homeostasis.