Transportin Mediates Nuclear Entry of DNA in Vertebrate Systems
Open Access
- 10 September 2009
- Vol. 10 (10), 1414-1428
- https://doi.org/10.1111/j.1600-0854.2009.00968.x
Abstract
Delivery of DNA to the cell nucleus is an essential step in many types of viral infection, transfection, gene transfer by the plant pathogen Agrobacteriumtumefaciens and in strategies for gene therapy. Thus, the mechanism by which DNA crosses the nuclear pore complex (NPC) is of great interest. Using nuclei reconstituted in vitro in Xenopus egg extracts, we previously studied DNA passage through the nuclear pores using a single‐molecule approach based on optical tweezers. Fluorescently labeled DNA molecules were also seen to accumulate within nuclei. Here we find that this import of DNA relies on a soluble protein receptor of the importin family. To identify this receptor, we used different pathway‐specific cargoes in competition studies as well as pathway‐specific dominant negative inhibitors derived from the nucleoporin Nup153. We found that inhibition of the receptor transportin suppresses DNA import. In contrast, inhibition of importin β has little effect on the nuclear accumulation of DNA. The dependence on transportin was fully confirmed in assays using permeabilized HeLa cells and a mammalian cell extract. We conclude that the nuclear import of DNA observed in these different vertebrate systems is largely mediated by the receptor transportin. We further report that histones, a known cargo of transportin, can act as an adaptor for the binding of transportin to DNA.Keywords
This publication has 119 references indexed in Scilit:
- Towards reconciling structure and function in the nuclear pore complexHistochemistry and Cell Biology, 2008
- Reversibility in nucleocytoplasmic transportProceedings of the National Academy of Sciences of the United States of America, 2007
- The Nup107-160 Nucleoporin Complex Is Required for Correct Bipolar Spindle AssemblyMolecular Biology of the Cell, 2006
- Rules for Nuclear Localization Sequence Recognition by Karyopherinβ2Cell, 2006
- Regulating Access to the Genome: Nucleocytoplasmic Transport throughout the Cell CycleCell, 2003
- Proteomic analysis of the mammalian nuclear pore complexThe Journal of cell biology, 2002
- Proteomic Analysis of Nucleoporin Interacting ProteinsOnline Journal of Public Health Informatics, 2001
- The Yeast Nuclear Pore ComplexThe Journal of cell biology, 2000
- Shuttling of pre-mRNA binding proteins between nucleus and cytoplasmNature, 1992
- Nuclear protein import in permeabilized mammalian cells requires soluble cytoplasmic factors.The Journal of cell biology, 1990