Rapid translocation of NTF2 through the nuclear pore of isolated nuclei and nuclear envelopes.
The mechanism by which macromolecules are translocated through the nuclear pore complex (NPC) is little understood. However, recent measurements of nuclear transport in permeabilized cells showed that molecules binding to phenylalanine-glycine-rich repeats (FG repeats) in NPC proteins were translocated much faster through the NPC than molecules not interacting with FG repeats. We have studied that substrate preference of the NPC in isolated oocyte nuclei and purified nuclear envelopes by optical single transporter recording. NTF2, the transport receptor of RanGDP, was exported approximately 30 times faster than green fluorescent protein, an inert molecule of approximately the same size. The data confirm that restricted diffusion of inert molecules and facilitated transport of FG-repeat binding proteins are basic types of translocation through the NPC, demonstrating that the functional integrity of the NPC can be conserved in isolated nuclei and nuclear envelopes and thus opening new avenues to the analysis of nucleocytoplasmic transport.
Siebrasse
Jan Peter
JP
Institut für Medizinische Physik und Biophysik, Universität Münster, Germany.
Peters
Reiner
R
D021581:Active Transport, Cell Nucleus; D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism*; D004926:Escherichia coli / Q000378:metabolism; D049452:Green Fluorescent Proteins; D006801:Humans; D007425:Intracellular Membranes / Q000378:metabolism; D007700:Kinetics; D008164:Luminescent Proteins / Q000378:metabolism; D029543:Nucleocytoplasmic Transport Proteins / Q000378:metabolism*; D009865:Oocytes / Q000378:metabolism; D038761:Photobleaching; D013997:Time Factors; D014981:Xenopus
D008164:Luminescent Proteins; D029543:Nucleocytoplasmic Transport Proteins; D049452:Green Fluorescent Proteins