Synemin Contains the Rod Domain of Intermediate Filaments

• Published in: Biochemical and biophysical research communications Vol. 213; no. 3; pp. 796 - 802
• Main Authors: Becker, B., Bellin, R.M., Sernett, S.W., Huiatt, T.W., Robson, R.M.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 24.08.1995
• Subjects: Amino Acid Sequence; Animals; Chickens; DNA, Complementary; Intermediate Filament Proteins - genetics; Intermediate Filament Proteins - metabolism; Intermediate Filaments - metabolism; Molecular Sequence Data; Muscle Proteins - genetics; Muscle Proteins - metabolism; RNA, Messenger - genetics; Sequence Homology, Amino Acid
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1006/bbrc.1995.2200

We have screened a λgt11 cDNA library from chicken gizzard muscle with polyclonal antiserum to avian synemin. Immunopositive clones were characterized and sequenced. Computer searches identified primarily intermediate filament (IF) proteins as being homologous to the synemin clones. Synemin′s sequence contained all structural features characteristic of the rod domain of IF proteins: (a) its length (approximately 310 amino acids), (b) the heptad repeat pattern of hydrophobic residues of coiled-coil proteins, (c) subdomain structure of the IF rod, by which helical subdomains (1A, 1B, 2A, and 2B) are separated by three short non-helical Linker regions, and (d) several potential intrahelical ion pairs along the sequence. We also confirmed the presence of the IF rod domain at the protein level by immunoblotting a proteolytic digest of synemin by using a monoclonal antibody specific to the rod domain of IFs.