Involvement of the consensus sequence motif at coil 2b in the assembly and stability of vimentin filaments

• DOI: 10.1242/jcs.102.1.31
• Publication Date: 2021-04-25T15:21:21Z
• Authors: Panos D. Kouklis; Peter Traub; Spyros D. Georgatos
• Keywords: Coiled coil; Sequence motif; Linker; Neurofilament

Nearly all intermediate filament (IF) proteins share two sequence motifs located at the N- and C-terminal ends of their helical rod domain (‘coil 1a’ ‘coil 2b’, respectively). To examine structural role coil 2b motif, we have performed in vitro assembly studies vivo microinjection experiments employing site-specific reagents: (a) a 20-residue synthetic peptide (C-2) representing conserved motif itself (b) monoclonal antibody (anti-IFA) that recognises an epitope within sequence. We demonstrate here vimentin protofilaments, when induced to assemble presence C-2 or anti-IFA, show lower propensity polymerise yield various abberant structures. The few filaments are formed under these conditions appear much shorter than normal IFs unravelled aggregated. Furthermore, preformed exposed most converted into filamentous forms possess morphology. None effects is seen subunits coincubated with control peptides. Microinjection anti-IFA cytoplasm interphasic 3T3 cells provokes collapse juxtanuclear mass formation numerous amorphous aggregates distributed throughout cytoplasm. These not microinjected cell nucleus. Our results provide experimental evidence supporting previous suggestions for assembly. propose this region interacting other sites along molecule interactions essential proper protofilament-protofilament alignment stability.