Insulin resistance is a common clinical feature of obesity and non-insulin-dependent
diabetes mellitus, and is characterized by elevated serum levels of glucose, insulin, and
lipids. The mechanism by which insulin resistance is acquired is unknown. We have
previously demonstrated that upon chronic treatment of fibroblasts with insulin, conditions
that mimic the hyperinsulinemia associated with insulin resistance, the membrane-
associated insulin receptor β subunit is proteolytically cleaved, resulting in the generation of …