RT Journal Article
SR Electronic
T1 The keratin-filament cycle of assembly and disassembly
JF Journal of Cell Science
JO J. Cell Sci.
FD The Company of Biologists Ltd
SP 2266
OP 2272
DO 10.1242/jcs.068080
VO 123
IS 13
A1 Kölsch, Anne
A1 Windoffer, Reinhard
A1 Würflinger, Thomas
A1 Aach, Til
A1 Leube, Rudolf E.
YR 2010
UL http://jcs.biologists.org/content/123/13/2266.abstract
AB Continuous and regulated remodelling of the cytoskeleton is crucial for many basic cell functions. In contrast to actin filaments and microtubules, it is not understood how this is accomplished for the third major cytoskeletal filament system, which consists of intermediate-filament polypeptides. Using time-lapse fluorescence microscopy of living interphase cells, in combination with photobleaching, photoactivation and quantitative fluorescence measurements, we observed that epithelial keratin intermediate filaments constantly release non-filamentous subunits, which are reused in the cell periphery for filament assembly. This cycle is independent of protein biosynthesis. The different stages of the cycle occur in defined cellular subdomains: assembly takes place in the cell periphery and newly formed filaments are constantly transported toward the perinuclear region while disassembly occurs, giving rise to diffusible subunits for another round of peripheral assembly. Remaining juxtanuclear filaments stabilize and encage the nucleus. Our data suggest that the keratin-filament cycle of assembly and disassembly is a major mechanism of intermediate-filament network plasticity, allowing rapid adaptation to specific requirements, notably in migrating cells.