Tektins are proteins that form filamentous polymers in the walls of ciliary and fiagellar microtubules and that have biochemical and immunological properties similar to those of intermediate-filament proteins. We report here the sequence of a cDNA for tektin A1, one of the main tektins from Strongylocentrotus purpuratus sea urchin embryos. By hybridization analysis, tektin A mRNA appears maximally at ciliogenesis. The predicted structure of tektin A1 (Mr 52,955) is a series of α-helical rod segments separated by nonhelical linkers. The two halves of the rod appear homologous and are probably related by gene duplication. Comparison of tektin A1 with intermediate-filament proteins, including nuclear lamins, reveals a low amino acid homology but similar molecular motif, i.e., pattern of helical and nonhelical domains. This study indicates that tektins are unique proteins but may be evolutionarily related to intermediate-filament proteins, and suggests a structural basis for the interaction of tektins and tubulin in microtubules.
|Original language||English (US)|
|Number of pages||5|
|Journal||Proceedings of the National Academy of Sciences of the United States of America|
|State||Published - 1992|
- Basal body