The Type III Effector HsvG of the Gall-Forming Pantoea agglomerans Mediates Expression of the Host Gene HSVGT

Autor: Gal Nissan, Shulamit Manulis-Sasson, Laura Chalupowicz, Doron Teper, Adva Yeheskel, Metsada Pasmanik-Chor, Guido Sessa, Isaac Barash
Jazyk: angličtina
Rok vydání: 2012
Předmět:
Zdroj: Molecular Plant-Microbe Interactions, Vol 25, Iss 2, Pp 231-240 (2012)
Druh dokumentu: article
ISSN: 1943-7706
0894-0282
DOI: 10.1094/MPMI-06-11-0173
Popis: The type III effector HsvG of the gall-forming Pantoea agglomerans pv. gypsophilae is a DNA-binding protein that is imported to the host nucleus and involved in host specificity. The DNA-binding region of HsvG was delineated to 266 amino acids located within a secondary structure region near the N-terminus of the protein but did not display any homology to canonical DNA-binding motifs. A binding site selection procedure was used to isolate a target gene of HsvG, named HSVGT, in Gypsophila paniculata. HSVGT is a predicted acidic protein of the DnaJ family with 244 amino acids. It harbors characteristic conserved motifs of a eukaryotic transcription factor, including a bipartite nuclear localization signal, zinc finger, and leucine zipper DNA-binding motifs. Quantitative real-time polymerase chain reaction analysis demonstrated that HSVGT transcription is specifically induced in planta within 2 h after inoculation with the wild-type P. agglomerans pv. gypsophilae compared with the hsvG mutant. Induction of HSVGT reached a peak of sixfold at 4 h after inoculation and progressively declined thereafter. Gel-shift assay demonstrated that HsvG binds to the HSVGT promoter, indicating that HSVGT is a direct target of HsvG. Our results support the hypothesis that HsvG functions as a transcription factor in gypsophila.
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