New genes and new biological roles for expansins.
Expansins are extracellular proteins that loosen plant cell walls in novel ways. They are thought to function in cell enlargement, pollen tube invasion of the stigma (in grasses), wall disassembly during fruit ripening, abscission and other cell separation events. Expansins are encoded by two multigene families and each gene is often expressed in highly specific locations and cell types. Structural analysis indicates that one expansin region resembles the catalytic domain of family-45 endoglucanases but glucanase activity has not been detected. The genome projects have revealed numerous expansin-related sequences but their putative wall-loosening functions remain to be assessed.
Cosgrove
D J
DJ
Department of Biology, 208 Mueller Laboratory, Pennsylvania State University, Pennsylvania, 16802, USA. dCosgrove@psu.edu
D000595:Amino Acid Sequence; D002473:Cell Wall / Q000502:physiology*; D017343:Genes, Plant; D019684:Magnoliopsida / Q000235:genetics*; D008969:Molecular Sequence Data; D005810:Multigene Family; D010940:Plant Proteins / Q000145:classification / Q000235:genetics*; D017386:Sequence Homology, Amino Acid
D010940:Plant Proteins; C095825:expansin protein, plant