Journal: Journal of Experimental Botany
Article Title: Protein–protein interactions as a proxy to monitor conformational changes and activation states of the tomato resistance protein I-2
doi: 10.1093/jxb/ers021
Figure Lengend Snippet: Identification of I-2 domains required for yeast two-hybrid (Y2H) interaction with I2I-1 and I2I-2. (A) Y2H analyses show interactions of I2I-1 or I2I-2 with full-length I-2 as bait, but not with Rx and Mi-1.2. I2I-1 and I2I-2 interact with the CC-NB-ARC bait of I-2 (amino acids 1–520), but not with bait constructs containing the CC-NB-ARC domains of I-2C1 (amino acids 1–526), Rx (amino acids 1–426), or Mi-1.2 (amino acids 161–896). The baits and preys did not show autoactivity when co-expressed with the pACT2 and pAS2-1 empty vectors. The test for activation of the HIS3 marker is shown after 10 days of growth (left panel). Expression of the bait proteins was confirmed by Western blot (WB) analyses using α-Gal4BD antibody detection on total yeast protein extracts (right panel). (B) Y2H analyses of I2I-1 and I2I-2 with various I-2 baits: I-2FL (full-length: amino acids 1–1266), I-2N+ (amino acids 1–643), I-2N (amino acids 1–520), I-2N ΔMHD (amino acids 1–520, with deletion at amino acids 484–496), and I-2CC (amino acids 1–170). The different I-2 (sub)domains are indicated and coloured: orange, coiled-coil (CC); red, nucleotide-binding (NB); purple, Apaf-1, R proteins, and Ced-4 (ARC) 1; blue, ARC2; and green, leucine-rich repeat (LRR). The test for activation of the ADE2 marker is shown after 5 days of growth; the other two markers ( HIS3, LacZ ) gave identical results. +, activation of all three selectable markers; –, no activation of these markers. The smallest part of I-2 enabling interaction with I2I-1 is the CC domain and for I2I-2 the CC-NB-ARC domain.
Article Snippet: The bait used for the library screen was constructed by subcloning the Nco I/ Sac I fragment of I-2 FL in the yeast two-hybrid (Y2H) bait vector pAS2-1 (Clontech Laboratories, Palo Alto, CA, USA), resulting in bait CC-NB-ARC-LRR1-12 (amino acids 1–872).
Techniques: Construct, Activation Assay, Marker, Expressing, Western Blot, Binding Assay