Dissection of TALE-dependent gene activation reveals that they induce transcription cooperatively and in both orientations

authored by: Jana Streubel, Heidi Baum, Jan Grau, Johannes Stuttman, Jens Boch
Abstract: Plant-pathogenic Xanthomonas bacteria inject transcription activator-like effector proteins (TALEs) into host cells to specifically induce transcription of plant genes and enhance susceptibility. Although the DNA-binding mode is well-understood it is still ambiguous how TALEs initiate transcription and whether additional promoter elements are needed to support this. To systematically dissect prerequisites for transcriptional initiation the activity of one TALE was compared on different synthetic Bs4 promoter fragments. In addition, a large collection of artificial TALEs spanning the OsSWEET14 promoter was compared. We show that the presence of a TALE alone is not sufficient to initiate transcription suggesting the requirement of additional supporting promoter elements. At the OsSWEET14 promoter TALEs can initiate transcription from various positions, in a synergistic manner of multiple TALEs binding in parallel to the promoter, and even by binding in reverse orientation. TALEs are known to shift the transcriptional start site, but our data show that this shift depends on the individual position of a TALE within a promoter context. Our results implicate that TALEs function like classical enhancer-binding proteins and initiate transcription in both orientations which has consequences for in planta target gene prediction and design of artificial activators.
Organisation(s): Section Plant Biotechnology
External Organisation(s): Martin Luther University Halle-Wittenberg
Type: Article
Journal: PLoS ONE
Volume: 12
ISSN: 1932-6203
Publication date: 16.03.2017
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: General Biochemistry,Genetics and Molecular Biology, General Agricultural and Biological Sciences, General
Electronic version(s): https://doi.org/10.1371/journal.pone.0173580 (Access: Open)