Theintermediate filaments (IFs) form major structural elements of the cytoskeleton. In vitro
analyses of these fibrous proteins reveal very different assembly properties for the nuclear
and cytoplasmic IF proteins. However, keratins in particular, the largest and most
heterogenous group of cytoplasmic IF proteins, have been difficult to analyze due to their
rapid assembly dynamics under the near-physiological conditions used for other IF proteins.
We show here that keratins, like other cytoplasmic IF proteins, go through a stage of …