title: Combining ChIP-chip and expression profiling to model the MoCRZ1 mediated circuit for Ca/calcineurin signaling in the rice blast fungus.
abstract: Significant progress has been made in defining the central signaling networks in many organisms, but collectively we know little about the downstream targets of these networks and the genes they regulate. To reconstruct the regulatory circuit of calcineurin signal transduction via MoCRZ1, a Magnaporthe oryzae C2H2 transcription factor activated by calcineurin dephosphorylation, we used a combined approach of chromatin immunoprecipitation - chip (ChIP-chip), coupled with microarray expression studies. One hundred forty genes were identified as being both a direct target of MoCRZ1 and having expression concurrently differentially regulated in a calcium/calcineurin/MoCRZ1 dependent manner. Highly represented were genes involved in calcium signaling, small molecule transport, ion homeostasis, cell wall synthesis/maintenance, and fungal virulence. Of particular note, genes involved in vesicle mediated secretion necessary for establishing host associations, were also found. MoCRZ1 itself was a target, suggesting a previously unreported autoregulation control point. The data also implicated a previously unreported feedback regulation mechanism of calcineurin activity. We propose that calcium/calcineurin regulated signal transduction circuits controlling development and pathogenicity manifest through multiple layers of regulation. We present results from the ChIP-chip and expression analysis along with a refined model of calcium/calcineurin signaling in this important plant pathogen.
authors.affiliation: Department of Plant Pathology, The Ohio State University, Columbus, Ohio, USA.
authors.forename: Soonok
authors.initials: S
authors.lastname: Kim
authors.forename: Jinnan
authors.initials: J
authors.lastname: Hu
authors.forename: Yeonyee
authors.initials: Y
authors.lastname: Oh
authors.forename: Jongsun
authors.initials: J
authors.lastname: Park
authors.forename: Jinhee
authors.initials: J
authors.lastname: Choi
authors.forename: Yong-Hwan
authors.initials: YH
authors.lastname: Lee
authors.forename: Ralph A
authors.initials: RA
authors.lastname: Dean
authors.forename: Thomas K
authors.initials: TK
authors.lastname: Mitchell
mesh_terms: D019703:Calcineurin / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism; D020869:Gene Expression Profiling; D016681:Genome, Fungal; D049452:Green Fluorescent Proteins / Q000235:genetics; D020082:Magnaporthe / Q000235:genetics*; D020411:Oligonucleotide Array Sequence Analysis; D012275:Oryza / Q000382:microbiology*; D010935:Plant Diseases / Q000382:microbiology; D015398:Signal Transduction / Q000502:physiology; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D005656:Fungal Proteins; D014157:Transcription Factors; D049452:Green Fluorescent Proteins; D019703:Calcineurin; D002118:Calcium