Quantitative proteomics reveals that plasma membrane microdomains from poplar cell suspension cultures are enriched in markers of signal transduction, molecular transport, and callose biosynthesis.
The plasma membrane (PM) is a highly dynamic interface that contains detergent-resistant microdomains (DRMs). The aim of this work was to determine the main functions of such microdomains in poplar through a proteomic analysis using gel-based and solution (iTRAQ) approaches. A total of 80 proteins from a limited number of functional classes were found to be significantly enriched in DRM relative to PM. The enriched proteins are markers of signal transduction, molecular transport at the PM, or cell wall biosynthesis. Their intrinsic properties are presented and discussed together with the biological significance of their enrichment in DRM. Of particular importance is the significant and specific enrichment of several callose [(1 → 3)-β-glucan] synthase isoforms, whose catalytic activity represents a final response to stress, leading to the deposition of callose plugs at the surface of the PM. An integrated functional model that connects all DRM-enriched proteins identified is proposed. This report is the only quantitative analysis available to date of the protein composition of membrane microdomains from a tree species.
Division of Glycoscience, School of Biotechnology, Royal Institute of Technology (KTH), AlbaNova University Centre, 106 91 Stockholm, Sweden.
Vaibhav
V
Srivastava
Erik
E
Malm
Gustav
G
Sundqvist
Vincent
V
Bulone
D001692:Biological Transport; D018929:Cell Culture Techniques; D002473:Cell Wall / Q000737:chemistry; D018506:Gene Expression Regulation, Plant; D005936:Glucans / Q000096:biosynthesis*; D005964:Glucosyltransferases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D007527:Isoenzymes / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D013058:Mass Spectrometry; D021962:Membrane Microdomains / Q000737:chemistry*; D058977:Molecular Sequence Annotation; D059828:Plant Cells / Q000737:chemistry* / Q000378:metabolism; D032107:Populus / Q000235:genetics / Q000378:metabolism*; D040901:Proteomics / Q000379:methods*; D015398:Signal Transduction; D013312:Stress, Physiological
D005936:Glucans; D007527:Isoenzymes; C048306:callose; D005964:Glucosyltransferases; C020570:1,3-beta-glucan synthase