Chapter 1 Part 2. Nucleus Cytoplasm Plasma membrane Phospholipid bilayer.
Compartments and Information Flow between Nucleus & Cytoplasm
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Transcript of Compartments and Information Flow between Nucleus & Cytoplasm
Compartments and Information Flow between
Nucleus & CytoplasmLecture 18 BSCI 420/421 Oct 14, 2002
“Your future is ahead of you” - Yogi Berra
1. Compartments of Eukaryotic cells
2. Information flow between Nucleus and cytoplasm
Compartments of a eukaryotic cell
Compartments of an animal cell
Flow chart of Eukaryotic cell
Molecules smaller than 9 nm or 60 KDa can enter nuclei by passive diffusion thru pores.Larger must have Nuclear Localization Signals (NLS) and be actively transported in.
Importance of NLS SV40 T-antigenWith normal orMutant NLS in infected cells.T-antigen detected by fluorAnti-T
The cycle of Ran, a monomeric G protein, gives directionality to nuclear import and export . Ran GTPase activating proteinIs cytosolic and Ran Guanine nucleotide exchange factor isNuclear.
Structure of Ran-GTP & How its binding to import receptor leads to release of cargo protein
Nuclear import and export depend on receptors& Ran cycle
Nuclear transport of Dorsal TF protein determines ventral cellsFrom dorsal cells in Drosophila embryos
Toll cell surface receptors areActivated by ventral signals,which leads to phosphorylation of an Inhibitor , cactus. This causes cactus to bedegraded, exposing the NLSon Dorsal, which enters the nucleus.