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Protein Interaction Maps and Model Organisms. Guang-Chao Chen IBC, Academia Sinica. Genome sizes of humans and other organisms.
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Protein Interaction Maps and Model Organisms Guang-Chao Chen IBC, Academia Sinica
Genome sizes of humans and other organisms Organism estimated size estimated gene average gene chromosome number density number Homo sapiens (human) 2900 million bases ~30,000 1 gene per 100,000 bases 46 Rattus norvegicus (rat) 2750 million bases ~30,000 1 gene per 100,000 bases 42 Mus musculus (mouse) 2500 million bases ~30,000 1 gene per 100,000 bases 40 Drosophila melanogaster 180 million bases 13,600 1 gene per 9,000 bases 8 (fruit fly) Arabidopsis thaliana 125 million bases 25,500 1 gene per 4000 bases 10 (plant) Caenorhabditis elegans 97 million bases 19,100 1 gene per 5000 bases 12 (roundworm) Saccharomyces cerevisia 12 million bases 6300 1 gene per 2000 bases 32 (yeast) Escherichia coli (bacteria) 4.7 million bases 3200 1 gene per 1400 bases 1
Conventional approaches: one or a few proteins Functional genomic approaches: tens of thousands of proteins -microarrays (gene expression profile) -large scale gene knockout (RNA-mediated interference) -large scale protein localization (GFP) -protein interaction maps
Protein interactions are crucial in many aspects of biological function.
Two directions for proteomics in protein interaction mapping. Gene (DNA) Transcription (RNA) Protein Genome Transcriptome Proteome Forward genetics Reverse genetics Reverse proteomics Classical proteomics
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Yeast mutants with cell-cycle defects Wild-type Haploid meiosis/ pat1 cdc2 cdc28 Nat Rev Genet. 2001
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expression of engrailed (en) GAL4-dependent ectopic expression of a gene (the GAL4-UAS system) Brand and Perrimon 1993 Development
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Quality control in high-throughput protein interaction networks • - Existing protein complex • Reproducibility of interactions • Evolutionary conservation • - Functional classification • - Subcellular localization • - Gene expression
Limitations of the yeast two-hybrid system • interaction in the nucleus • not suitable for membrane proteins and large-size proteins • may not undergo posttranslational modification
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