Molecular Plant Advance Access originally published online on August 10, 2009
Molecular Plant 2009 2(5):977-989; doi:10.1093/mp/ssp059
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Plant Cell Wall Proteomics: Mass Spectrometry Data, a Trove for Research on Protein Structure/Function Relationships
Surfaces Cellulaires et Signalisation chez les Végétaux, UMR 5546 CNRS–UPS–Université de Toulouse, Pôle de Biotechnologie Végétale, 24 chemin de Borde-Rouge, BP 42617 Auzeville, 31326 Castanet-Tolosan, France
1 To whom correspondence should be addressed. E-mail jamet{at}scsv.ups-tlse.fr, fax +33 562 193 502, tel. +33 562 193 530.
Proteomics allows the large-scale study of protein expression either in whole organisms or in purified organelles. In particular, mass spectrometry (MS) analysis of gel-separated proteins produces data not only for protein identification, but for protein structure, location, and processing as well. An in-depth analysis was performed on MS data from etiolated hypocotyl cell wall proteomics of Arabidopsis thaliana. These analyses show that highly homologous members of multigene families can be differentiated. Two lectins presenting 93% amino acid identity were identified using peptide mass fingerprinting. Although the identification of structural proteins such as extensins or hydroxyproline/proline-rich proteins (H/PRPs) is arduous, different types of MS spectra were exploited to identify and characterize an H/PRP. Maturation events in a couple of cell wall proteins (CWPs) were analyzed using site mapping. N-glycosylation of CWPs as well as the hydroxylation or oxidation of amino acids were also explored, adding information to improve our understanding of CWP structure/function relationships. A bioinformatic tool was developed to locate by means of MS the N-terminus of mature secreted proteins and N-glycosylation.
Key Words: Cell wall protein • MALDI–TOF • mass spectrometry • post-translational modification • protein structure • proteomics