Basal bodies organize the nine doublet microtubules found in cilia. Cilia are required for a variety of cellular functions, including motility and sensing stimuli. Understanding this biochemically complex organelle requires an inventory of the molecular components and the contribution each makes to the overall structure. We define a basal body proteome and determine the specific localization of basal body components in the ciliated protozoan Tetrahymena thermophila. Using a biochemical, bioinformatic, and genetic approach, we identify 97 known and candidate basal body proteins. 24 novel T. thermophila basal body proteins were identified, 19 of which were localized to the ultrastructural level, as seen by immunoelectron microscopy. Importantly, we find proteins from several structural domains within the basal body, allowing us to reveal how each component contributes to the overall organization. Thus, we present a high resolution localization map of basal body structure highlighting important new components for future functional studies.

Due to a printing error, Fig. 4 appeared as a grayscale image. It appears in color in the online version and has been reprinted in color below. Figure 4. New T. thermophila basal body components were shown to localize to discrete structural domains. Protein localizations were assigned to specifi c domains if at least 20% of all gold particles in the immunoelectron microscopy compilation images are associated with the region. New protein components are listed in Fig. 2 B and in Figs. S1-3 (available at http://www.jcb.org/cgi/content/full/jcb.200703109/DC1). Color reference and domain are listed for each new basal body component described.

Four kindreds of east Arnhem Land Australian aboriginal people from Groote Eylandt and adjacent communities display symptoms of a similar spinocerebellar degeneration (multiple-system degenerative disease). The familial pattern indicates an autosomal dominant inheritance, though with varying penetrance in different families. This condition is clinically and pathologically consistent with Machado-Joseph disease (MJD), and there is the possibility of Portuguese ancestry. These families exhibit anticipation, particularly in the case of paternal inheritance, with those with earlier age of onset presenting a clinical pattern consistent with MJD type I. There was no expansion of the CAG repeat region of the SCA1 gene in these families. The demonstration of expansion of the CAG repeat on chromosome 14q32.1 in all four families confirms the diagnosis of MJD.

No abstract