title: A rod domain sequence in segment 1B triggers dimerisation of the two small Branchiostoma IF proteins B2 and A3.
abstract: Previously, we cloned two Branchiostoma IF proteins A3 and B2 and demonstrated that both can form heteropolymeric IF based on a coiled coil dimer consisting of one B2 and one A3 polypeptide. In this study we continued in the characterisation of the B2/A3 heterodimer by searching for the sequences that play an important role in the triggering of the B2/A3 heterodimer. Using a series of deletion and chimeric B2, A3 and B1 constructs and the overlay assay as a tool, we were able to identify a part of the B2 sequence (segment 1A, linker L1 and the N-terminal part of segment 1B) which retains the ability of the full length protein B2 to specifically recognize A3 in blot overlays. Moreover, inspection of this A3-competent B2 fragment identified a short sequence in segment 1B which shares with the currently known trigger-like motif of cortexillin and other coiled coil proteins potential to form multiple inter-chain ionic interactions. Thus, a common and essential feature of trigger sequences with different primary structures found so far in IF and other coiled coil proteins seems to be their ability to form multiple inter-chain ionic interactions which brings the chains close to one another and allows coiled coil formation to propagate accordingly.
authors.affiliation: SEMBID, s.r.o.-Research Center of Applied Biomedical Diagnostics, Prešov, Slovakia. sembid.pp@gmail.com
authors.forename: Anton
authors.initials: A
authors.lastname: Karabinos
authors.forename: Jürgen
authors.initials: J
authors.lastname: Schünemann
authors.forename: David A D
authors.initials: DA
authors.lastname: Parry
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D002816:Chordata, Nonvertebrate / Q000737:chemistry*; D007381:Intermediate Filament Proteins / Q000737:chemistry* / Q000378:metabolism; D008969:Molecular Sequence Data; D055503:Protein Multimerization; D017434:Protein Structure, Tertiary
chemical_list: D007381:Intermediate Filament Proteins