Judelson lab research: promoter analysis

Spatial patterns of expression of several spore-specific promoters, as revealed using transformants expressing the GUS marker gene

Demonstration that a 7-nt "cold box" is responsible for the induction of genes during cold-induced zoosporogenesis. This sequence was identified through the testing mutagenized versions of the PinfC promoter in transgenic P. infestans.

Identification of two regions in a promoter required for sporulation-specific transcription.

EMSA assay performed using wild type and mutant versions of binding regions from zoosporogenesis-specific promoter

Schema used to identify over-represented motifs and mark high-priority candidates for functional analysis.


Home page General and contact information Howard Judelson's background education and interests The oomycetes learn more about these exciting organisms The late blight disease learn more about the problems that P. infestans causes Research Interests Ongoing research projects Other lab members Publications Opportunities for graduate study in the lab		Promoter dissection and analysis of transcriptional networks A major goal of the laboratory is to understand how Phytophthora regulates the expression of stage specific genes, such as those transcribed only during sporulation or during zoospore formation. Based on microarray and macroarray analyses, >1000 genes that show differential regulation during sporulation or zoosporogenesis were identified. Using fusions between the promoters of those genes and the beta-glucuronidase (GUS) or green fluorescent protein (GFP) reporters, we identified promoter regions required for stage-specific expression. Spatial patterns of expression of several spore-specific promoters, as revealed using transformants expressing the GUS marker gene To identify the binding sites of transcription factors, biochemical, genetic, and bioinformatic approaches are being used. For example, by making mutations in promoters we can identify stretches of DNA that are required for stage-specific expression. Demonstration that a 7-nt "cold box" is responsible for the induction of genes during cold-induced zoosporogenesis. This sequence was identified through the testing mutagenized versions of the PinfC promoter in transgenic P. infestans. Identification of two regions in a promoter required for sporulation-specific transcription. Electrophoretic Mobility Shift (EMSA) assays have helped to confirm and narrow down the precise sequences that bind transcription factors. EMSA assay performed using wild type and mutant versions of binding regions from zoosporogenesis-specific promoter Bioinformatic approaches have also been used to scan coordinately-regulated genes for putative binding sites for shared transcription factors. Schema used to identify over-represented motifs and mark high-priority candidates for functional analysis. Once protein-DNA complexes are identified, the proteins are extracted and subjected to microsequence analysis (using Edman degradation or mass spectroscopy approaches). The protein sequences can then be used to clone the genes for the transcription factors. Results of protein microsequencing Once a transcription factor has been identified, its gene can be silenced in transformants using antisense or RNAi methodology. Microarray studies can then compare wild-type versus the silenced strain, to identify the genes regulated by the transcription factors. Back to top Research areas Home page and contact info Publications Graduate Studies updated 12.31.09

Promoter dissection and analysis of transcriptional networks