title: The CELLULOSE-SYNTHASE LIKE C (CSLC) family of barley includes members that are integral membrane proteins targeted to the plasma membrane.
abstract: The CELLULOSE SYNTHASE-LIKE C (CSLC) family is an ancient lineage within the CELLULOSE SYNTHASE/CELLULOSE SYNTHASE-LIKE (CESA/CSL) polysaccharide synthase superfamily that is thought to have arisen before the divergence of mosses and vascular plants. As studies in the flowering plant Arabidopsis have suggested synthesis of the (1,4)-beta-glucan backbone of xyloglucan (XyG), a wall polysaccharide that tethers adjacent cellulose microfibrils to each other, as a probable function for the CSLCs, CSLC function was investigated in barley (Hordeum vulgare L.), a species with low amounts of XyG in its walls. Four barley CSLC genes were identified (designated HvCSLC1-4). Phylogenetic analysis reveals three well supported clades of CSLCs in flowering plants, with barley having representatives in two of these clades. The four barley CSLCs were expressed in various tissues, with in situ PCR detecting transcripts in all cell types of the coleoptile and root, including cells with primary and secondary cell walls. Co-expression analysis showed that HvCSLC3 was coordinately expressed with putative XyG xylosyltransferase genes. Both immuno-EM and membrane fractionation showed that HvCSLC2 was located in the plasma membrane of barley suspension-cultured cells and was not in internal membranes such as endoplasmic reticulum or Golgi apparatus. Based on our current knowledge of the sub-cellular locations of polysaccharide synthesis, we conclude that the CSLC family probably contains more than one type of polysaccharide synthase.
authors.affiliation: Plant Cell Biology Research Centre, School of Botany, University of Melbourne, Victoria 3010, Australia.
authors.forename: Fenny M
authors.initials: FM
authors.lastname: Dwivany
authors.forename: Dina
authors.initials: D
authors.lastname: Yulia
authors.forename: Rachel A
authors.initials: RA
authors.lastname: Burton
authors.forename: Neil J
authors.initials: NJ
authors.lastname: Shirley
authors.forename: Sarah M
authors.initials: SM
authors.lastname: Wilson
authors.forename: Geoffrey B
authors.initials: GB
authors.lastname: Fincher
authors.forename: Antony
authors.initials: A
authors.lastname: Bacic
authors.forename: Ed
authors.initials: E
authors.lastname: Newbigin
authors.forename: Monika S
authors.initials: MS
authors.lastname: Doblin
mesh_terms: D015153:Blotting, Western; D002462:Cell Membrane / Q000201:enzymology* / Q000648:ultrastructure; D002473:Cell Wall / Q000378:metabolism* / Q000648:ultrastructure; D019295:Computational Biology; D005936:Glucans / Q000378:metabolism; D016695:Glycosyltransferases; D001467:Hordeum / Q000145:classification / Q000201:enzymology* / Q000648:ultrastructure; D008565:Membrane Proteins / Q000378:metabolism*; D016253:Microscopy, Immunoelectron; D008969:Molecular Sequence Data; D010802:Phylogeny; D010940:Plant Proteins / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D014990:Xylans / Q000378:metabolism
chemical_list: D005936:Glucans; D008565:Membrane Proteins; D010940:Plant Proteins; D014990:Xylans; C029353:xyloglucan; D016695:Glycosyltransferases