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13 Cards in this Set
- Front
- Back
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Who worked with C. elegans?
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Robert Horvitz - MIT
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Details of C. elegans?
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-roundworms
-easy to grow -translucent -code for each cell -stable mutants -apoptosis was discovered here -10 rounds of division 959 cells in hermaphrodite, 1031 in male |
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Details of microRNA?
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-heterochronic mutatnts - different timing
-doesn't code for proteins -inhibits translation of other mRNA |
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Which cells do not have nuclei? Why?
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Skin, RBC, lens fiber
b/c big different in refractive indices |
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Nuclear Pore details?
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-site of mRNA protein exchange
-allows < 62.5 kD to diffuse anything >62.5 kD must enter via ATP-dependent transport |
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What are histones important for?
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packaging DNA
- <20 kD nuclear protein |
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What are non-histones important for?
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transcription factors, regulatory in nature
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Where can nucleoplasmins be found?
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X. laevis eggs
-10% of proteins |
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Explain the experiment with nucleoplasmin.
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Extract nuclear proteins --> gel filtration --> nucleoplasmins --iodinization--> inject with 125-I --> after SDS gels at time 0 mins --> find bands at cytoplasm at 65 and 33 kDa
Extract nuclear proteins --> gel filtration --> nucleoplasmins --iodinization--> inject with 125-I --> after SDS gels at time 30 mins --> find bands at nucleus at 65 and 33 kDa therefore, nucleoplasmins are a pentamer of 33 kDa |
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Can a monomeric unit translate?
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Yes
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What is important for translocation?
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tail has the targetting info
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Where does translocation occur?
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Nuclear pore.
- label nuclear pore with gold particles and cool to 4 degrees celsius (on outside) --> after heating to 22-27 degrees celsius --> gold particles are on the inside of the nucleus |
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What are lamins? Details?
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-intermediate filaments
- three classes: A, B, C -line the nucleus -connect DNA to the envelope -when phosphorylated (by MPF) --> breaks down --> cannot hold chromosomes together --> chromosomes separate -regular nuclear dissolution during mitosis |
