AtTCTP and AtCSN4 interact <i>in vitro</i> and <i>in vivo</i>.

(a) TCTP interacting proteins were co-immunoprecipitated from protein extracts prepared from inflorescences of 35S::GFP, AtTCTPg-GFP, 35S::AtTCTP-GFP and 35S::dTCTP-GFP/tctp plants using anti-GFP coupled magnetic beads. Co-immunoprecipitated proteins were detected by Western blotting using anti-CSN4 (upper panel), anti-TCTP (middle panel) or anti-GFP (lower panel) antibodies. White asterisks: CSN4 protein; black arrows: TCTP-GFP protein; black asterisks: free GFP. (b) CSN4 interacting proteins were co-immunoprecipitated from protein extracts prepared from inflorescences of Col-0, 35S::AtCSN4-GFP and 35S::AtCSN4-GFP/35S::AtTCTP plants using anti-GFP coupled magnetic beads. Co-immunoprecipitated proteins were detected by Western blotting using anti-CSN4 (upper panel) or anti-TCTP (lower panel) antibodies. White asterisks: CSN4 protein; white arrow: CSN4-GFP protein; black asterisks: TCTP protein. (c) AtCSN4-GFP (green) and AtTCTP-mCherry (red) co-localize in tobacco leaves. Bars: 50 μm. (d) Bimolecular Fluorescence complementation experiments in tobacco leaves show that AtTCTP and AtCSN4 fused with either C- or N-terminal YFP moieties, interact in vivo. Bars: 50 μm. As shown in S2 Fig, no signal was observed in the control BiFC assays in which AtTCTP or AtCSN4 fused with N- or C-terminal YFP moieties was co-infiltrated with an empty plasmid.