Sfr1, a Tetrahymena thermophila Sfi1 repeat protein, modulates the production of cortical row basal bodies

Westley Heydeck, Alexander J. Stemm-Wolf, Janin Knop, Christina C. Poh, Mark Winey

Research output: Contribution to journalArticlepeer-review

3 Scopus citations


Basal bodies are essential microtubule-based structures that template, anchor, and orient cilia at the cell surface. Cilia act primarily in the generation of directional fluid flow and sensory reception, both of which are utilized for a broad spectrum of cellular processes. Although basal bodies contribute to vital cell functions, the molecular contributors of their assembly and maintenance are poorly understood. Previous studies of the ciliate Tetrahymena thermophila revealed important roles for two centrin family members in basal body assembly, separation of new basal bodies, and stability. Here, we characterize the basal body function of a centrin-binding protein, Sfr1, in Tetrahymena. Sfr1 is part of a large family of 13 proteins in Tetrahymena that contain Sfi1 repeats (SFRs), a motif originally identified in Saccharomyces cerevisiae Sfi1 that binds centrin. Sfr1 is the only SFR protein in Tetrahymena that localizes to all cortical row and oral apparatus basal bodies. In addition, Sfr1 resides predominantly at the microtubule scaffold from the proximal cartwheel to the distal transition zone. Complete genomic knockout of SFR1 (sfr1Δ) causes a significant increase in both cortical row basal body density and the number of cortical rows, contributing to an overall overproduction of basal bodies. Reintroduction of Sfr1 into sfr1Δ mutant cells leads to a marked reduction of cortical row basal body density and the total number of cortical row basal bodies. Therefore, Sfr1 directly modulates cortical row basal body production. This study reveals an inhibitory role for Sfr1, and potentially centrins, in Tetrahymena basal body production.

Original languageEnglish (US)
Article numbere00257-16
Issue number6
StatePublished - Nov 1 2016


  • Basal body
  • Centrin
  • Centriole
  • Ciliates
  • Sfi1 repeat
  • Tetrahymena

ASJC Scopus subject areas

  • Microbiology
  • Molecular Biology


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