Schematic representation of TC receptor-mediated uptake of TC-Cbl via clathrin-coated pits and vesicles. The empty TC receptor recycles back to the cell surface while TC undergoes proteolytic degradation and release of Cbl. After processing, Cbl is targeted to cytoplasmic methionine synthase and mitochondrial methylmalonyl-CoA mutase (MMA-CoA mutase).