Protein Phosphorylations As a Mode of Insulin Action

Within minutes after the interaction of insulin with its receptor, marked changes occur in the metabolic pattern of the cell. In classic target tissues, insulin inhibits catabolic pathways (e.g., glycogenolysis and lipolysis), concurrently activating anabolic pathways (such as glycogen synthesis and de novo fatty acid synthesis). These effects are due to alterations in the activity of a variety of intracellular enzymes and transcellular transport processes. Over a longer period of time, insulin also participates in regulating the expression of specific genes and, in certain cell types, insulin modulates cell division and growth.