[Nielsen et al., 2001: Curr Biol 11:529-533], based on studies in Drosophila, have proposed that β tubulin in axonemal microtubules must contain a specific acidic seven amino acid sequence in its carboxyl terminus. In mammals, the two βIV isotypes (βIVa and βIVb) contain that sequence. In order to test the application of this hypothesis to mammals, we have examined the expression of β tubulin isotypes in four different ciliated tissues (trachea, ependyma, uterine tube, and testis) using isotype-specific antibodies and indirect immunofluorescence. We find that βIV tubulin is present in all ciliated cell types examined, but so is β1 tubulin. Taken together with recent studies that show that β1 and βIV tubulin are both present in the cilia of vestibular hair cells, olfactory neurons, and nasal respiratory epithelial cells, we propose that both β1 tubulin and βIV tubulin may be required for axonemal structures in mammals.
All Science Journal Classification (ASJC) codes
- Structural Biology
- Cell Biology