An MBoC Favorite: Identification of novel principles of keratin filament turnover in living cells

In celebration of MBoC's first 20 years, members of the Editorial Board, members of the ASCB Council, and others comment on their favorite MBoC papers from the past two decades.

This study examines the attributes of keratin intermediate filaments in single, live, nonmotile epithelial cells under steady-state conditions. From their substantive findings, the authors proposed a spatially and temporally defined “keratin cycle” that accounts for the genesis, maturation, and turnover of keratin filaments in the setting of live epithelial cells in culture. I suspect that, just like me, many researchers did not expect that the process of assembly to turnover of keratin filaments would be so vectorial and spatially well-defined, even if it ultimately applies only to a cell culture setting. The “keratin cycle” also provided a conceptual framework from which to examine the relationships among keratin filaments, F-actin, microtubules, and adhesion complexes. The model has been refined since, and several of the predictions it originally generated have been upheld through subsequent experimentation. Finally, this study provided an alternative view of intermediate filament dynamics at steady state, complementing similar efforts from other researchers.