| Abstract Detail
Cell Walls Xiao, Wei [1], Tierney, Mary [2]. Identification of primary sequences sufficient for crosslinking proline-rich proteins within the root hair cell wall of Arabidopsis thaliana. Proline-rich proteins (PRPs) represent one family of cell wall structural proteins that are expressed in a large number of plant species and are thought to function in plant development. We have previously shown that two members of this gene family, AtPRP1 and AtPRP3, are expressed in root hairs and that their protein products accumulate in different regions of the root hair cell wall. In addition, AtPRP1 and AtPRP3 null mutants exhibit distinct plant growth phenotypes. In order to investigate the biochemical interactions through which PRPs function within the cell wall, we generated transgenic arabidopsis plants expressing a nested deletion series within the crosslinking domain of ATPRP1 and ATPRP3. All of the truncated versions of ATPRP1 and ATPRP3 were found to crosslink within the root hair cell wall. These data suggest that 25 aa of the crosslinking domain, containing only 3 copies of the pentapeptide PPVKY, is sufficient for the insolubilization of ATPRP1 and ATPRP3 within the cell wall. In contrast, when a PRP with a crosslinking domain consisting of seven copies of the pentapetide PPVYK in tandem was expressed in arabidopsis the majority of the protein remained salt-extractable from the cell wall. Work from other laboratories has suggested that VYK may be a common crosslinking motif for proline/hydroxyproline-rich cell wall proteins. The work presented here indicates that the amino acid context surrounding the putative VYK crosslinking sequence within proline-rich proteins is important for their insolubilization within the plant cell wall. Future studies are designed to characterize whether the expression of these truncated versions of ATPRP1 and ATPRP3 are able to rescue the mutant phenotypes observed in atprp1 and atprp3 null mutants. Log in to add this item to your schedule
1 - The University of Vermont, Department of Plant Biology, 120B Marsh Life Science Building, Burlington, VT, 05405, USA 2 - The University of Vermont, Department of Plant Biology
Keywords: PRP crosslinking.
Presentation Type: ASPB Minisymposium Session: M13 Location: International Ballroom/Hilton Date: Monday, July 9th, 2007 Time: 11:05 AM Number: M13002 Abstract ID:659 |