Live imaging of single nuclear pores reveals unique assembly kinetics and mechanism in interphase.
In metazoa, new nuclear pore complexes (NPCs) form at two different cell cycle stages: at the end of mitosis concomitant with the reformation of the nuclear envelope and during interphase. However, the mechanisms of these assembly processes may differ. In this study, we apply high resolution live cell microscopy to analyze the dynamics of single NPCs in living mammalian cells during interphase. We show that nuclear growth and NPC assembly are correlated and occur at a constant rate throughout interphase. By analyzing the kinetics of individual NPC assembly events, we demonstrate that they are initiated by slow accumulation of the membrane nucleoporin Pom121 followed by the more rapid association of the soluble NPC subcomplex Nup107-160. This inverse order of recruitment and the overall much slower kinetics compared with postmitotic NPC assembly support the conclusion that the two processes occur by distinct molecular mechanisms.
Dultz
Elisa
E
European Molecular Biology Laboratory, Cell Biology and Biophysics Unit, D-69117 Heidelberg, Germany.
Ellenberg
Jan
J
D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism / Q000648:ultrastructure; D007399:Interphase; D007700:Kinetics; D008565:Membrane Proteins / Q000378:metabolism; D022022:Nuclear Pore / Q000378:metabolism / Q000648:ultrastructure*; D028861:Nuclear Pore Complex Proteins / Q000378:metabolism; D009687:Nuclear Proteins / Q000378:metabolism; D051381:Rats
D008565:Membrane Proteins; D028861:Nuclear Pore Complex Proteins; D009687:Nuclear Proteins; C088025:Nup107 protein, rat; C553332:Nup160 protein, rat; C082264:Pom121 protein, rat