Arabidopsis plasma membrane proteomics identifies components of transport, signal transduction and membrane trafficking.
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 transmembrane 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.
Alexandersson
Erik
E
Department of Plant Biochemistry, Center for Chemistry and Chemical Engineering, Lund University, P.O. Box 124, SE-22100 Lund, Sweden. erik.alexandersson@plantbio.lu.se
Saalbach
Gerhard
G
Larsson
Christer
C
Kjellbom
Per
P
D017360:Arabidopsis / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000032:analysis* / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism*; D015180:Electrophoresis, Gel, Two-Dimensional; D013058:Mass Spectrometry; D008565:Membrane Proteins / Q000032:analysis* / Q000378:metabolism; D021381:Protein Transport; D040901:Proteomics; D015398:Signal Transduction
D029681:Arabidopsis Proteins; D008565:Membrane Proteins