| Abstract Detail
Cell Walls Carter, Jamie [1], Tierney, Mary [2]. Two cell wall proteins are specifically targeted to the modified cell wall surrounding the stomatal pore in A. thaliana. Plant stomata are specialized cells that perform critical functions during respiration and photosynthesis. Stomata consist of two opposing guard cells that join to create the stomatal pore consisting of an electron dense modified cell wall. ATPRP2 and ATPRP4 are structural cell wall proteins expressed in guard cells that are characterized by a non-proline rich unique domain and a proline rich domain defined by a PPVYK repetitive motif. We show that ATPRP4 accumulates within the asymmetrical thickening known as the inner ledge, while ATPRP2 is deposited in the wall surrounding the internal airspace. While the proline rich domain of these proteins has been implicated in isodityrosine crosslinking, there is little known about the function of the unique domain. To investigate this, transgenic plants expressing chimeric constructs of ATPRP2 and ATPRP4 were analyzed. Chimeric proteins containing an ATPRP4 unique domain and an ATPRP2 crosslinking domain accumulated within the inner ledge while proteins containing an ATPRP2 unique domain and an ATPRP4 crosslinking domain were detected in the wall surrounding the internal pore. These results show that the unique domains of these proteins are sufficient for their localization in vivo. To further characterize sequences within these proteins that are important for their targeted secretion, we have generated a series of deletions within the unique domains of ATPRP2 and ATPRP4 and have introduced these constructs into Arabidopsis plants. Analysis of these transgenic lines may help to identify specific amino acid motifs that function in the polarized secretion of ATPRP2 and ATPRP4 within the stomatal cell wall, and provide a model for the directed deposition of proteins in cell wall growth.
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1 - University of Vermont, Microbiology & Molecular Genetics, 201 Stafford Hall, 95 Carrigan Dr, UVM, Burlington, Vermont, 05405, USA
2 - University of Vermont, Plant Biology
Keywords:
cell wall
stomata
Proline-rich protein
localization.
Presentation Type: Plant Biology Abstract
Session: P
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM
Number: P17003
Abstract ID:123 |
