title: The biology of arabinogalactan proteins.
abstract: Arabinogalactan proteins is an umbrella term applied to a highly diverse class of cell surface glycoproteins, many of which contain glycosylphosphatidylinositol lipid anchors. The structures of protein and glycan moieties of arabinogalactan proteins are overwhelmingly diverse while the "hydroxproline contiguity hypothesis" predicts arabinogalactan modification of members of many families of extracellular proteins. Descriptive studies using monoclonal antibodies reacting with carbohydrate epitopes on arabinogalactan proteins and experimental work using beta-Yariv reagent implicate arabinogalactan proteins in many biological processes of cell proliferation and survival, pattern formation and growth, and in plant microbe interaction. Advanced structural understanding of arabinogalactan proteins and an emerging molecular genetic definition of biological roles of individual arabinogalactan protein species, in conjunction with potentially analogous extracellular matrix components of animals, stimulate hypotheses about their mode of action. Arabinogalactan proteins might be soluble signals, or might act as modulators and coreceptors of apoplastic morphogens; their amphiphilic molecular nature makes them prime candidates of mediators between the cell wall, the plasma membrane, and the cytoplasm.
authors.affiliation: Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Colney, Norwich, United Kingdom. georg.seifert@boku.ac.at
authors.forename: Georg J
authors.initials: GJ
authors.lastname: Seifert
authors.forename: Keith
authors.initials: K
authors.lastname: Roberts
mesh_terms: D017209:Apoptosis; D017360:Arabidopsis / Q000196:embryology / Q000378:metabolism* / Q000382:microbiology; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*; D019521:Body Patterning; D002455:Cell Division; D002473:Cell Wall / Q000378:metabolism; D047108:Embryonic Development; D016326:Extracellular Matrix Proteins / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*; D021962:Membrane Microdomains / Q000378:metabolism; D009088:Mucoproteins / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*; D010940:Plant Proteins / Q000737:chemistry / Q000378:metabolism / Q000502:physiology; D053205:Pollen Tube / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D029681:Arabidopsis Proteins; D016326:Extracellular Matrix Proteins; D009088:Mucoproteins; D010940:Plant Proteins; C006619:arabinogalactan proteins