Insulin signal transduction pathway (also known as glucose homeostasis) also exhibits oscillatory behavior. On a pathological basis, this topic is crucial to understanding certain disorders in the body such as diabetes, hyperglycemia and hypoglycemia. The functioning of a signal transduction pathway is based on extra-cellular signaling that in turn creates a response which causes other subsequent responses, hence creating a chain reaction, or cascade. During the course of signaling, the cell uses each response for accomplishing some kind of a purpose along the way. Insulin secretion mechanism is a common example of signal transduction pathway mechanism. Insulin is produced by the pancreas in a
Insulin the brand name Humulin. The vast majority of insulin currently used worldwide is now biosynthetic recombinant "human" insulin or its analogues. Recombinant insulin is produced either in yeast (usually "Saccharomyces cerevisiae") or "E. coli". In yeast, insulin may be engineered as a single-chain protein with a KexII endoprotease (a yeast homolog of PCI/PCII) site that separates the insulin A chain from a c-terminally truncated insulin B chain. A chemically synthesized c-terminal tail is then grafted onto insulin by reverse proteolysis using the inexpensive protease trypsin; typically the lysine on the c-terminal tail is protected with a chemical protecting group to