Open AccessInteraction with a Host Ubiquitin-Conjugating Enzyme Is Required for the Pathogenicity of a Geminiviral DNA β Satellite
Author(s) -
Omid Eini,
Satish C. Dogra,
Luke A. Selth,
Ian B. Dry,
J. W. Randles,
M. Ali Rezaian
Publication year - 2009
Publication title -
molecular plant-microbe interactions
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.565
H-Index - 153
eISSN - 1943-7706
pISSN - 0894-0282
DOI - 10.1094/mpmi-22-6-0737
Subject(s) - bimolecular fluorescence complementation , biology , protein fragment complementation assay , complementation , mutant , dna , complementary dna , two hybrid screening , ubiquitin , fusion protein , ubiquitin conjugating enzyme , gene , microbiology and biotechnology , biochemistry , ubiquitin ligase , recombinant dna
DNA beta is a single-stranded satellite DNA which encodes a single gene, betaC1. To better understand the role of betaC1 in the pathogenicity of DNA beta, a yeast two-hybrid screen of a tomato cDNA library was carried out using betaC1 from Cotton leaf curl Multan virus (CLCuMV) DNA beta as the bait. A ubiquitin-conjugating enzyme, designated SlUBC3, which functionally complemented a yeast mutant deficient in ubiquitin-conjugating enzymes was identified. The authenticity and specificity of the interaction between betaC1 and SlUBC3 was confirmed both in vivo, using a bimolecular fluorescence complementation assay, and in vitro, using a protein-binding assay. Analysis of deletion mutants of the betaC1 protein showed that a myristoylation-like motif is required both for its interaction with SlUBC3 and the induction of DNA-beta-specific symptoms in host plants. The level of polyubiquitinated proteins in transgenic tobacco plants expressing betaC1 was found to be reduced compared with wild-type plants. These results are consistent with the hypothesis that interaction of betaC1 with SlUBC3 is required for DNA-beta-specific symptom induction, and that this is possibly due to downregulation of the host ubiquitin proteasome pathway.