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Mapping signaling networks through genetic interaction analysis by RNAi. Thomas Sandmann Department of Signaling and Functional Genomics, German Cancer Research Institute (DKFZ) Heidelberg. Genetic interaction maps in yeast. “DNA replication and repair subcluster ”, Collins et al, 2007.
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Mapping signaling networks through genetic interaction analysis by RNAi Thomas Sandmann Department of Signaling and Functional Genomics, German Cancer Research Institute (DKFZ) Heidelberg
Genetic interaction maps in yeast “DNA replication and repair subcluster”, Collins et al, 2007
RNAi Specificity Efficiency Reproducibility
Mapping genetic interactions using RNAi Pilot study: 96 Drosophila signaling proteins + controls Expression verified in S2 cells (RNAseq) • Specificity: • 2 independent long dsRNAs / gene • Latest design criteria • Efficiency: • qPCR validation of all reagents • Reproducibility: • 8 technical + 2 biological replicates NextRNAi, Horn, Sandmann, Boutros, Genome Biol, 2010
RNAi2 Horn, Sandmann, Fischer et al, submitted
Predicting co-RNAi phenotypes main effect of dsRNAj baseline error term interaction term measurement (growth, cells, …) main effect of dsRNAi
RNAi2 > 70.000 assays Reproducibility: Features : R=0.95 (cell number) Interactions: R=0.62 (cell number)
Genetic interaction matrix: nuclear area Nuclear area
Observing different features revealsnon-redundant sets of interactions FDR < 0.05 Significant enrichment of annotated Drosophila genetic interacions and orthologous human protein-protein interactions
Identifying pathway components Training and classification using sparse Linear Discriminant Analysis (LDA) Distance to the apexes: predicted class probabilities Circle diameter: probability of assignment to any of the three classes
Attenuation of basal Ras/MAPK activity HEK293T cells, starved O/N in in serum-free medium Drosophila S2 cells, starved O/N in serum-free medium
Cka binds to known Ras/MAPKregulators Co-IPs from Drosophila S2 cells
Conclusions Quantitative, combinatorial RNAi yields informative genetic interaction profiles in vitro. Analysis of different phenotypes reveals non-redundant sets of interactions. Cka is a novel, conserved regulator of Ras/MAPK signaling. High-throughput mapping of genetic interactions in metazoan cells
Outlook: Interaction network of chromatin biology 1400 gene, annotated or uncharacterized 2 dsRNAs / gene High-resolution fluorescence microscopy (HOECHST, Tubulin, phospho-His3) ctrl dsRNA Rho1 dsRNA Dynein light chain dsRNA
Acknowledgements Thomas Horn Bernd Fischer ElinAxelson Michael Boutros Wolfgang Huber