Arabidopsis plasma membrane proteomics identifies components of transport, signal transduction and membrane trafficking

• Published in: Plant and cell physiology Vol. 45; no. 11; pp. 1543 - 1556
• Main Authors: Alexandersson, E. (Lund Univ. (Sweden)), Saalbach, G, Larsson, C, Kjellbom, P
• Format: Journal Article
• Language: English
• Published: Japan Oxford University Press 01.11.2004; Oxford Publishing Limited (England)
• Subjects: AHA; ARABIDOPSIS; Arabidopsis - metabolism; Arabidopsis Proteins - analysis; Arabidopsis Proteins - metabolism; Biologi; Biological Sciences; Cell Membrane - metabolism; CELL MEMBRANES; Electrophoresis, Gel, Two-Dimensional; H+-inorganic pyrophosphatase; H+-PPiase; Keywords: Arabidopsis — Integral membrane proteins — Peripheral membrane proteins — Plasma membrane proteins — Proteome; Mass Spectrometry; Membrane Proteins - analysis; Membrane Proteins - metabolism; Natural Sciences; Naturvetenskap; NUTRIENT TRANSPORT; PIP; plasma membrane H+-ATPase; plasma membrane intrinsic protein; Protein Transport; PROTEINS; Proteomics; Signal Transduction; syntaxin; SYP; TIP; tonoplast intrinsic protein
• ISSN: 0032-0781; 1471-9053; 1471-9053
• DOI: 10.1093/pcp/pch209

In order to identify integral proteins and peripheral proteins associated with the plasma membrane, highly purified Arabidopsis plasma membranes from green tissue (leaves and petioles) were analyzed by mass spectrometry. Plasma membranes were isolated by aqueous two-phase partitioning, which yields plasma membrane vesicles with a cytoplasmic-side-in orientation and with a purity of 95%. These vesicles were turned inside-out by treatment with Brij 58 to remove soluble contaminating proteins enclosed in the vesicles and to remove loosely bound contaminating proteins. In total, 238 putative plasma membrane proteins were identified, of which 114 are predicted to have trans-membrane domains or to be glycosyl phosphatidylinositol anchored. About two-thirds of the identified integral proteins have not previously been shown to be plasma membrane proteins. Of the 238 identified proteins, 76% could be classified according to function. Major classes are proteins involved in transport (17%), signal transduction (16%), membrane trafficking (9%) and stress responses (9%). Almost a quarter of the proteins identified in the present study are functionally unclassified and more than half of these are predicted to be integral.