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Spatiotemporally tracking of nano-biofilaments inside the nuclear pore complex core

Research Authors
Mahmoud Shaaban Mohamed, Masaharu Hazawa, Akiko Kobayashi, Laurent Guillaud, Takahiro Watanabe-Nakayama, Mizuho Nakayama, Hanbo Wang, Noriyuki Kodera, Masanobu Oshima, Toshio Ando, Richard W Wong
Research Abstract

Nuclear pore complex (NPC) is a gating nanomachine with a central selective barrier composed mainly of Nups, which contain intrinsically disordered (non-structured) regions (IDRs) with phenylalanine-glycine (FG) motifs (FG-NUPs). The NPC central FG network dynamics is poorly understood, as FG-NUPs liquid-liquid phase separation (LLPS) have evaded structural characterization. Moreover, the working mechanism of single FG-NUP-biofilaments residing at the central lumen is unknown. In general, flexible biofilaments are expected to be tangled and knotted during their motion and interaction. However, filament knotting visualization in real-time and space has yet to be visualized at the nanoscale. Here, we report a spatiotemporally tracking method for FG-NUP organization with nanoscale resolution, unveiling FG-NUP conformation in NPCs of colorectal cells and organoids at timescales of ~150 ms using high-speed atomic force microscopy (HS-AFM). Tracking of FG-NUP single filaments revealed that single filaments have a heterogeneous thickness in normal and cancer models which in turn affected the filament rotation and motion. Notably, FG-NUPs are overexpressed in various cancers. Using the FG-NUP inhibitor, trans-1,2-cyclohexanediol, we found that central plug size was significantly reduced and incompletely reversible back to filamentous structures in aggressive colon cancer cells and organoids. These data showed a model of FG-NUPs reversible self-assembly devolving into the central plug partial biogenesis. Taken together, HS-AFM enabled the tracking and manipulation of single filaments of native FG-NUPs which has remained evasive for decades.

Research Department
Research Journal
Biomaterials
Research Publisher
Elsevier
Research Rank
1
Research Vol
256
Research Website
https://www.sciencedirect.com/science/article/pii/S0142961220304440
Research Year
2020
Research Pages
120198