Capturing directed molecular motion in the nuclear pore complex of live cells.
Nuclear pore complexes (NPCs) are gateways for nucleocytoplasmic exchange. Intrinsically disordered nucleoporins (Nups) form a selective filter inside the NPC, taking a central role in the vital nucleocytoplasmic transport mechanism. How such intricate meshwork relates to function and gives rise to a transport mechanism is still unclear. Here we set out to tackle this issue in intact cells by an established combination of fluorescence correlation spectroscopy and real-time tracking of the center of mass of single NPCs. We find the dynamics of nucleoporin Nup153 to be regulated so as to produce rapid, discrete exchange between two separate positions within the NPC. A similar behavior is also observed for both karyopherinβ1 transport-receptor and cargoes destined to nuclear import. Thus, we argue that directed Nup-mediated molecular motion may represent an intrinsic feature of the overall selective gating through intact NPCs.
Center for Nanotechnology Innovation at National Enterprise for nanoScience and nanoTechnology, Istituto Italiano di Tecnologia, 56127 Pisa, Italy.
Francesco
F
Cardarelli
Luca
L
Lanzano
Enrico
E
Gratton
D000818:Animals; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D049452:Green Fluorescent Proteins / Q000378:metabolism; D022022:Nuclear Pore / Q000378:metabolism*; D028861:Nuclear Pore Complex Proteins / Q000378:metabolism; D021381:Protein Transport; D013050:Spectrometry, Fluorescence
D028861:Nuclear Pore Complex Proteins; D049452:Green Fluorescent Proteins