Proteomic analysis of the Arabidopsis thaliana cell wall.
With the completion of the Arabidopsis genome, many hypothetical proteins have been predicted without any information on their expression, subcellular localisation and function. We have performed proteomic analysis of proteins sequentially extracted from enriched Arabidopsis cell wall fractions and separated by two-dimensional gel electrophoresis (2-DE). The proteins were identified by peptide mass fingerprinting using matrix-assisted laser desorption/ionisation-time of flight (MALDI-TOF) mass spectrometry and genomic database searches. This is part of a targeted exercise to establish the entire Arabidopsis secretome database. We report evidence for new proteins of unknown function whose existence had been predicted from genomic sequences and, furthermore, localise them to the cell wall. In addition, we observed an unexpected presence in the cell wall preparations of proteins whose known biochemical activity has never been associated with this compartment hitherto. We discuss the implications of these findings and present results suggesting a possible involvement of cell wall kinases in plant responses to pathogen attack.
Chivasa
Stephen
S
Creative Gene Technology Ltd., Integrative Cell Biology Laboratory, School of Biological and Biomedical Sciences, University of Durham, Durham, UK.
Ndimba
Bongani K
BK
Simon
William J
WJ
Robertson
Duncan
D
Yu
Xiao-Lan
XL
Knox
J Paul
JP
Bolwell
Paul
P
Slabas
Antoni R
AR
D017360:Arabidopsis / Q000737:chemistry* / Q000166:cytology; D029681:Arabidopsis Proteins / Q000032:analysis / Q000302:isolation & purification*; D002473:Cell Wall / Q000737:chemistry; D015180:Electrophoresis, Gel, Two-Dimensional; D010449:Peptide Mapping; D010766:Phosphorylation; D011494:Protein Kinases / Q000302:isolation & purification / Q000378:metabolism; D021382:Protein Sorting Signals; D040901:Proteomics; D022142:Secretory Vesicles; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D029681:Arabidopsis Proteins; D021382:Protein Sorting Signals; D011494:Protein Kinases