Nuclear entry

Vielhaber E, Eide E, Rivers A, Gao ZH, Virshup DM 2000 Nuclear entry of the circadian regulator mPERl is controlled by mammalian casein kinase I epsilon. Mol Cell Biol 20 4888-4899... 

Kosbash They are not mutually exclusive. This doesn t exclude the fact that this is dependent on prior PER—TIM interactions. The lack of temporal coordination of PER and TIM s nuclear entry could be dependent on a prior cytoplasmic association. This would be very reasonable. 

Nuclear entry of plasmids in the absence of cell division... 

Figure 12.5 Nuclear import in permeabilized cells. HeLa cells were grown on coverslips and permeabilized with digitonin as described in Wilson et al., 1999. Fluorescein-PNA-labeled plasmids (containing the SV40 enhancer, 4.2 kb) or rhodamine-labeled BSA-NLS peptide conjugates were incubated with the cells for four hours at which time they were viewed by fluorescence microscopy. With no additions, neither DNA nor protein was imported, but in the presence of nuclear and cytoplasmic extracts both substrates localized to the nuclei. While plasmids containing the SV40 enhancer were taken up by the nuclei, those lacking the sequence were excluded. The remaining panels demonstrate the need for both the import machinery (importins and Ran) and a source of adapter proteins (nuclear extract) for plasmid nuclear entry, but not for protein nuclear localization.

Dean, D.A., Dean, B.S., Muller, S. and Smith, L.C. (1999b) Sequence requirements for plasmid nuclear entry. Exp. Cell Res., 253, 713-722. 

Decomplex at ion Nuclear entry Gene expression Persistence Drug-controlled... 

Figure 14.7 Schematic representation of the process of gene delivery and expression. Extacellular environment —> tissue targetability —> cellular uptake —> intracellular trafficking —> nuclear entry —> gene expression...

Nuclear entry has been described as a formidable barrier to gene delivery [201-203]. Transport of DNA into this target organelle most likely involves the nuclear pore complex, which has an inner channel size of 9 nm, as determined by electron microscopy [204]. Molecules less than 40-45 kDa diffuse freely through the... 

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