Abstract
SummaryCilia and flagella are organelles essential for motility and sensing of environmental stimuli. Depending on the cell type, cilia acquire a defined set of functions and, accordingly, are built with an appropriate length and molecular composition. Several ciliary proteins display a high degree of conservation throughout evolution and mutations in ciliary genes are associated with various diseases such as ciliopathies and infertility. Here, we describe the role of the highly conserved ciliary protein, Bug22, in Drosophila. Previous studies in unicellular organisms have shown that Bug22 is required for proper cilia function, but its exact role in ciliogenesis has not been investigated yet. Null Bug22 mutant flies display cilia-associated phenotypes and nervous system defects. Furthermore, sperm differentiation is blocked at the individualization stage, due to impaired migration of the individualization machinery. Tubulin post-translational modifications (PTMs) such as polyglycylation, polyglutamylation or acetylation, are determinants of microtubule (MT) functions and stability in centrioles, cilia and neurons. We found defects in the timely incorporation of polyglycylation in sperm axonemal MTs of Bug22 mutants. In addition, we found that depletion of human Bug22 in RPE1 cells resulted in the appearance of longer cilia and reduced axonemal polyglutamylation. Our work identifies Bug22 as a protein that plays a conserved role in the regulation of PTMs of the ciliary axoneme.
Highlights
Cilia are specialized cell organelles that have motility and sensory functions. Their axoneme is built through nucleation of MTs from a basal body anchored at the plasma membrane, while assembly of the remaining cilia components normally relies on cargo transportation, in a process known as intraflagellar transport (IFT)
Drosophila and human body up regulated gene 22 (Bug22) are associated with cilia In Drosophila, Bug22 is encoded by the CG5343 gene, which codes for a protein with an estimated mass of,23 kDa
Our work shows that Bug22 influences the size of organelles that contain an axoneme such as centrioles and basal bodies, both in the male germline in Drosophila as well as the primary cilium of RPE1 cells
Summary
Cilia are specialized cell organelles that have motility and sensory functions. Their axoneme is built through nucleation of MTs from a basal body anchored at the plasma membrane, while assembly of the remaining cilia components normally relies on cargo transportation, in a process known as intraflagellar transport (IFT). In the last decade several high throughput studies have contributed to the identification of cilia and centrosome components (Andersen et al, 2003; Avidor-Reiss et al, 2004; Keller et al, 2005; Li et al, 2004; Pazour et al, 2005; Stolc et al, 2005). One of these components is the Basal body up regulated gene 22 (Bug22), initially identified as a basal body component in the green algae Chlamydomonas reinhardtii (Keller et al, 2005). Bug is not exclusively associated with basal bodies, and with cilia, in Chlamydomonas, Tetrahymena, Paramecia, mouse and human cells (Dawe et al, 2007; Pazour et al, 2005; Laligneet al., 2010; Ostrowski et al, 2002; Smith et al, 2005; Ishikawa et al, 2012)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
