ABSTRACT
The cytoskeleton of eukaryotic cells is a highly dynamic, interlinked
network composed of actin filaments, microtubules, and intermedi-
ate filaments. Despite their common filamentous nature, all three
systems differ greatly in structure and mechanical properties, and
a better understanding of their individual and synergistic contri-
butions to overall cell function is a main objective in cell biological
research. Atomic force microscopy (AFM) has been instrumental in
investigating the structure and function of cytoskeletal components,
because its high spatial resolution allows imaging and manipulating
the cytoskeleton at the single-filament level. Importantly, because
AFM scanning can be performed in aqueous solutions, the cytoskele-
ton can be studied under physiological conditions and even in the
context of living cells. Recent developments in high-speed AFM
scanning have made it furthermore possible to observe dynamic
rearrangement of cytoskeletal elements processes directly in real
time. Using the atomic force microscope tip as a nanosurgery tool,
single filaments can also be manipulated to test their mechanical
properties. Here I review a range of AFM applications for studying
the structure and function of cytoskeletal filaments, including high-
resolution scanning of native cytoskeletons in living and de-roofed
cells and the imaging and nanomanipulation of single cytoskeletal
filaments assembled in vitro.
