The AvrM effector from flax rust has a structured C-terminal domain and interacts directly with the M resistance protein.
In plant immunity, recognition of pathogen effectors by plant resistance proteins leads to the activation of plant defenses and a localized cell death response. The AvrM effector from flax rust is a small secreted protein that is recognized by the M resistance protein in flax. Here, we investigate the mechanism of M-AvrM recognition and show that these two proteins directly interact in a yeast two-hybrid assay, and that this interaction correlates with the recognition specificity observed for each of the different AvrM variants. We further characterize this interaction by demonstrating that the C-terminal domain of AvrM is required for M-dependent cell death, and show that this domain also interacts with the M protein in yeast. We investigate the role of C-terminal differences among the different AvrM proteins for their involvement in this interaction and establish that M recognition is hindered by an additional 34 amino acids present at the C terminus of several AvrM variants. Structural characterization of recombinant AvrM-A protein revealed a globular C-terminal domain that dimerizes.
Catanzariti
Ann-Maree
AM
Department of Plant and Microbial Biology, 111 Koshland Hall, University of California, Berkley 94720-3102, USA.
Dodds
Peter N
PN
Ve
Thomas
T
Kobe
Bostjan
B
Ellis
Jeffrey G
JG
Staskawicz
Brian J
BJ
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000235:genetics; D001487:Basidiomycota / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D016923:Cell Death; D019597:Flax / Q000235:genetics / Q000378:metabolism / Q000382:microbiology*; D007113:Immunity, Innate; D008969:Molecular Sequence Data; D010935:Plant Diseases / Q000382:microbiology*; D010940:Plant Proteins / Q000737:chemistry / Q000378:metabolism; D011110:Polymorphism, Genetic; D011485:Protein Binding; D020798:Two-Hybrid System Techniques
D000596:Amino Acids; D010940:Plant Proteins