Post-translational modifications of intermediate filament proteins: mechanisms and functions

Intermediate filaments (IFs) are cytoskeletal and nucleoskeletal structures that promote cell integrity and intracellular communication and contribute to subcellular and tissue-specific functions. Our understanding of how post-translational modifications of IF proteins (including nuclear lamins and cytoplasmic keratins, vimentin, desmin, neurofilaments and glial fibrillary acidic protein, among others) regulate IF function is increasing. Intermediate filaments (IFs) are cytoskeletal and nucleoskeletal structures that provide mechanical and stress-coping resilience to cells, contribute to subcellular and tissue-specific biological functions, and facilitate intracellular communication. IFs, including nuclear lamins and those in the cytoplasm (keratins, vimentin, desmin, neurofilaments and glial fibrillary acidic protein, among others), are functionally regulated by post-translational modifications (PTMs). Proteomic advances highlight the enormous complexity and regulatory potential of IF protein PTMs, which include phosphorylation, glycosylation, sumoylation, acetylation and prenylation, with novel modifications becoming increasingly appreciated. Future studies will need to characterize their on–off mechanisms, crosstalk and utility as biomarkers and targets for diseases involving the IF cytoskeleton.