title: Expansins.
abstract: Biochemical dissection of the "acid-growth" process of plant cell walls led to the isolation of a new class of wall loosening proteins, called expansins. These proteins affect the rheology of growing walls by permitting the microfibril matrix network to slide, thereby enabling the wall to expand. Molecular sequence analysis suggests that expansins might have a cryptic glycosyl transferase activity, but biochemical results suggest that expansins disrupt noncovalent bonding between microfibrils and the matrix. Recent discoveries of a new expansin family and gene expression in fruit meristems and cotton fibers have enlarged our view of the developmental functions of this group of wall loosening proteins.
authors.affiliation: Department of Biology, Pennsylvania State University, University Park 16802, USA.
authors.forename: M W
authors.initials: MW
authors.lastname: Shieh
authors.forename: D J
authors.initials: DJ
authors.lastname: Cosgrove
mesh_terms: D002458:Cell Fractionation; D048429:Cell Size / Q000502:physiology; D002473:Cell Wall / Q000502:physiology; D002482:Cellulose / Q000378:metabolism; D018553:Cucumis sativus / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D016695:Glycosyltransferases / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D018546:Hypocotyl / Q000166:cytology / Q000502:physiology*; D020894:Microfibrils / Q000502:physiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology
chemical_list: D010940:Plant Proteins; C095825:expansin protein, plant; D002482:Cellulose; D016695:Glycosyltransferases; C073693:xyloglucan endotransglycosylase