A bacterial effector acts as a plant transcription factor and induces a cell size regulator.
Pathogenicity of many Gram-negative bacteria relies on the injection of effector proteins by type III secretion into eukaryotic cells, where they modulate host signaling pathways to the pathogen's benefit. One such effector protein injected by Xanthomonas into plants is AvrBs3, which localizes to the plant cell nucleus and causes hypertrophy of plant mesophyll cells. We show that AvrBs3 induces the expression of a master regulator of cell size, upa20, which encodes a transcription factor containing a basic helix-loop-helix domain. AvrBs3 binds to a conserved element in the upa20 promoter via its central repeat region and induces gene expression through its activation domain. Thus, AvrBs3 and likely other members of this family provoke developmental reprogramming of host cells by mimicking eukaryotic transcription factors.
Kay
Sabine
S
Institute of Biology, Department of Genetics, Martin-Luther-University Halle-Wittenberg, Weinbergweg 10, D-06120 Halle (Saale), Germany.
Hahn
Simone
S
Marois
Eric
E
Hause
Gerd
G
Bonas
Ulla
U
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D051792:Basic Helix-Loop-Helix Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D002212:Capsicum / Q000166:cytology / Q000235:genetics* / Q000382:microbiology*; D049108:Cell Enlargement; D048429:Cell Size; D047369:Chromatin Immunoprecipitation; D018506:Gene Expression Regulation, Plant; D020868:Gene Silencing; D008969:Molecular Sequence Data; D018515:Plant Leaves / Q000166:cytology / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D011401:Promoter Regions, Genetic; D014026:Nicotiana / Q000235:genetics; D014158:Transcription, Genetic; D016959:Xanthomonas campestris / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity
D001426:Bacterial Proteins; D051792:Basic Helix-Loop-Helix Proteins; D010940:Plant Proteins