INTERMEDIATE FILAMENT PROTEINS - CYTOSKELETAL ELEMENTS WITH GENE-REGULATORY FUNCTION

Intermediate filament (IFs) probably represents one of the last functionally important macromolecular protein assemblies of the eukaryotic cell whose biological role has not yet been unveiled. This chapter discusses the cellular function of IFs, which is based on some characteristic reactivities of their constituent protein subunits with nuclear components in vitro. The structure and function of the IF proteins and their oligo- and polymeric forms are compared with a variety of gene-regulatory protein factors and nuclear matrix elements and shown to have many features in common with these compounds. IF proteins are a class of regulatory DNA binding factors which, in accordance with their developmentally and tissue-specifically regulated expression, may play an important role in cell differentiation as one of their major biological functions. © 1994, Academic Press Inc.