E. Cohen
2010
Citations
9
Influential Citations
87
Citations
Quality indicators
Journal
Advances in Insect Physiology
Abstract
Abstract Chitin is an abundant extracellular amino-sugar polymer that in association with other external biomacromolecules (carbohydrates, proteins) is an essential structural component in forming cell walls in fungi as well as exoskeletons and peritrophic membranes in arthropods. Chitin synthesis and degradation in insects are cyclical dynamic events, and since being crucial for facilitating growth and development, are strictly coordinated and regulated. Chitin formation and hydrolysis are complex, multi-faceted, interconnected and highly harmonized intracellular and extracellular cascades of biochemical and biophysical transformations. The list of processes, many of which are still poorly understood, include transcriptional, translational and post-translational modifications relative to the catalytic machinery; cellular movement of clustered catalytic units to and their eventual fixed spatial integration into plasma membranes; chitin polymerization and translocation of polymers across the cell membrane barrier; coalescence of nascent external chitin chains forming crystallites that subsequently associate with assorted proteins to form fibrillar supramacromolecular structures. Cloned and sequenced genes encoding the anabolic chitin synthase, and the catabolic chitinase, β- N -acetylglucosaminidase and chitin deacetylase combined with purification and characterization of the expressed enzymes as well as crystallographic and inhibition studies were instrumental in elucidating the intricate mechanisms of catalysis relative to chitin polymerization and degradation. The powerful tools of RNAi knockout methodologies were harnessed for functional analysis of a variety of chitin-related genes. Chitin research carries practical aspect as the physiologically crucial synthesis and hydrolysis of the polymer have been regarded as suitable, attractive and largely selective targets for interference and for producing effective pharmaceuticals and safe biopesticides.