Book contents
- Frontmatter
- Contents
- List of contributors
- Preface by HIROSHI OKAMOTO
- Introductory overview by HIROSHI OKAMOTO
- I The molecular biology of peptide hormones in the islets of Langerhans
- 1 The organization and structure of insulin genes
- 2 The regulation of insulin gene expression
- 3 The translational control of proinsulin synthesis by glucose
- 4 The structure and regulation of the glucagon gene
- 5 The structure and regulation of the somatostatin gene
- 6 The mosaic evolution of the pancreatic polypeptide gene
- 7 The structure and expression of genes of vasoactive intestinal peptide and related peptides
- 8 Pancreastatin: a novel pancreatic hormone
- 9 The processing of peptide precursors
- II Molecular aspects of diabetes mellitus
- Index
1 - The organization and structure of insulin genes
Published online by Cambridge University Press: 10 December 2009
- Frontmatter
- Contents
- List of contributors
- Preface by HIROSHI OKAMOTO
- Introductory overview by HIROSHI OKAMOTO
- I The molecular biology of peptide hormones in the islets of Langerhans
- 1 The organization and structure of insulin genes
- 2 The regulation of insulin gene expression
- 3 The translational control of proinsulin synthesis by glucose
- 4 The structure and regulation of the glucagon gene
- 5 The structure and regulation of the somatostatin gene
- 6 The mosaic evolution of the pancreatic polypeptide gene
- 7 The structure and expression of genes of vasoactive intestinal peptide and related peptides
- 8 Pancreastatin: a novel pancreatic hormone
- 9 The processing of peptide precursors
- II Molecular aspects of diabetes mellitus
- Index
Summary
Introduction
Insulin is a two-chain disulfide-linked polypeptide hormonen which is essential for normal growth and metabolic regulation in higher organisms. It is a member of a superfamily of structurally related peptides which includes relaxin (a two-chain polypeptide hormone that functions in vertebrate reproductive physiology (Bryant-Greenwood, 1982)) and insulin-like growth factors (IGF) I and II. IGF-I and -II are single-chain polypeptides which stimulate growth in vitro and in vivo and are probably required for normal fetal and postnatal growth and development (Froesch & Zapf, 1985). Insulin is also related to two invertebrate neuropeptides that have recently been isolated and characterized: prothoracicotrophic hormone of the silkworm Bombyx mori, which regulates the secretion of the molting hormone ecdysone (Nagasawa et al, 1986; Jhoti et al, 1987); and molluscan insulin-related peptide (MIP) (Smit et al, 1988), a pond snail (Lymnaea stagnalis) hormone, which is synthesized by the cerebral light-green cell and is believed to regulate, at least in part, growth of soft body parts and shell and glycogen metabolism. These invertebrate insulin-like proteins are two-chain polypeptide hormones like insulin and relaxin and in contrast to the single-chain IGFs. Although the origins and relationships of the various members of the insulin gene family have not been clarified, it seems likely that they evolved from a common ancestral protein through a process of gene duplication and diversification. Furthermore, the presence of two non-allelic insulin or relaxin genes in some vertebrate species suggests that this process is still ongoing.
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- Molecular Biology of the Islets of Langerhans , pp. 9 - 26Publisher: Cambridge University PressPrint publication year: 1990
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