[The molecular mechanism of insulin biosynthesis and mutant insulin gene syndrome]

The biosynthetic process of insulin in pancreatic beta cells consists of many steps including transcription of insulin gene to mRNA, translation of mRNA to preproinsulin, production of proinsulin by cleavage of signal peptide, and conversion of proinsulin to insulin and C-peptide. This process also includes intra-cellular trafficking (nucleus, cytoplasm, endoplasmic reticulum, Golgi apparatus, secretary granule, and extra-cellular secretion). The factors concerning and regulating these steps are discussed, although some of these have not been fully understood. The possible influences of insulin gene mutations (mutant insulin gene syndrome) to these steps are also discussed. Understanding of the molecular mechanism of insulin biosynthesis might be usefull to explain the defective insulin production of NIDDM.