Entry clones containing the CaMV 35S promoter, the bait ORF and the GS-TAP tag were recombined by MultiSite Gateway LR reaction with pKCTAP as destination vector [66] , [67] . Arabidopsis cell suspension cultures (PSB-D) were transformed without callus selection as described previously [68] (link). Tandem affinity purifications were performed as described [67] , [68] (link) with the exception that the soluble protein fraction was obtained by centrifuging twice at 36,900 g for 20 min at 4°C.
Proteolysis and peptide isolation, acquisition of mass spectra by a 4800 MALDI TOF/TOF Proteomics Analyzer (AB SCIEX), and MS-based protein homology identification based on the TAIR genomic database [69] were performed as described in [39] (link). Experimental background proteins were subtracted based on approximately 40 TAP experiments on wild-type cultures and cultures expressing TAP-tagged mock GUS, RFP and GFP proteins [39] (link).
Proteolysis and peptide isolation, acquisition of mass spectra by a 4800 MALDI TOF/TOF Proteomics Analyzer (AB SCIEX), and MS-based protein homology identification based on the TAIR genomic database [69] were performed as described in [39] (link). Experimental background proteins were subtracted based on approximately 40 TAP experiments on wild-type cultures and cultures expressing TAP-tagged mock GUS, RFP and GFP proteins [39] (link).