Journal article
Nanomechanical interactions of phenylalanine-glycine nucleoporins studied by single molecule force-volume spectroscopy.
- Lim RY M.E. Müller Institute for Structural Biology, Biozentrum, University of Basel, Klingelbergstrasse 70, Basel 4056, Switzerland. roderick.lim@unibas.ch
- Köser J
- Huang NP
- Schwarz-Herion K
- Aebi U
- 2007-04-21
Published in:
- Journal of structural biology. - 2007
English
Phenylalanine-glycine (FG)-repeat nucleoporins (Nups) form the major components of the selective gating mechanism in the nuclear pore complex (NPC). Hence, a primary requirement is to understand how they vacillate between preventing the access of passively diffusing molecules and promoting the translocation of receptor-bound cargo into the NPC. To shed light on such behavior, we have studied the nanomechanical properties of a cysteine-modified FG-rich C-terminal domain of hNup153 (i.e., cNup153) and its interactions with importin-beta. This is carried out using single molecule force spectroscopy (SMFS) with the atomic force microscope (AFM). In the absence of importin-beta, cNup153 is highly flexible and can be reversibly stretched and relaxed without any change to its intrinsic entropic elasticity, indicating a lack of intra-FG interactions, i.e., natively unfolded. Importin-beta-modified AFM tips reveal complex binding topologies with cNup153, and provide evidence for binding promiscuity in FG-receptor interactions. These differences suggest that cooperativity between FG-domains arises from FG-receptor interactions instead of FG-FG interactions. On a technical note, this work highlights an improved SMFS technique which involves pre-passivating the underlying substrate surface with polyethylene glycol to reduce undesirable AFM tip-surface effects. A high yield of acceptable data is subsequently obtained from the low surface coverage of target molecules by implementing SMFS measurements in force-volume (FV) mode.
- Language
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- English
- Open access status
- closed
- Identifiers
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- DOI 10.1016/j.jsb.2007.01.018
- PMID 17446086
- Persistent URL
- https://sonar.ch/global/documents/205488
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