1. Dysfunction of the ciliary ARMC9/TOGARAM1 protein module causes Joubert syndrome
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Latour, Brooke L., Van De Weghe, Julie C., Rusterholz, Tamara D.S., Letteboer, Stef J.F., Gomez, Arianna, Shaheen, Ranad, Gesemann, Matthias, Karamzade, Arezou, Asadollahi, Mostafa, Barroso-Gil, Miguel, Chitre, Manali, Grout, Megan E., van Reeuwijk, Jeroen, van Beersum, Sylvia E.C., Miller, Caitlin V., Dempsey, Jennifer C., Morsy, Heba, Bamshad, Michael J., Nickerson, Deborah A., Neuhauss, Stephan C.F., Boldt, Karsten, Ueffing, Marius, Keramatipour, Mohammad, Sayer, John A., Alkuraya, Fowzan S., Bachmann-Gagescu, Ruxandra, Roepman, Ronald, and Doherty, Dan
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Cellular signal transduction ,Proteins ,Health care industry - Abstract
Joubert syndrome (JBTS) is a recessive neurodevelopmental ciliopathy characterized by a pathognomonic hindbrain malformation. All known JBTS genes encode proteins involved in the structure or function of primary cilia, ubiquitous antenna-like organelles essential for cellular signal transduction. Here, we used the recently identified JBTS-associated protein armadillo repeat motif-containing 9 (ARMC9) in tandem-affinity purification and yeast 2-hybrid screens to identify a ciliary module whose dysfunction underlies JBTS. In addition to the known JBTS-associated proteins CEP104 and CSPP1, we identified coiled-coil domain containing 66 (CCDC66) and TOG array regulator of axonemal microtubules 1 (TOGARAM1) as ARMC9 interaction partners. We found that TOGARAM1 variants cause JBTS and disrupt TOGARAM1 interaction with ARMC9. Using a combination of protein interaction analyses, characterization of patient-derived fibroblasts, and analysis of CRISPR/ Cas9-engineered zebrafish and hTERT-RPE1 cells, we demonstrated that dysfunction of ARMC9 or TOGARAM1 resulted in short cilia with decreased axonemal acetylation and polyglutamylation, but relatively intact transition zone function. Aberrant serum-induced ciliary resorption and cold-induced depolymerization in ARMC9 and TOGARAM1 patient cell lines suggest a role for this new JBTS-associated protein module in ciliary stability., Introduction Ciliopathies are a heterogeneous class of disorders that arise from defects in the structure or function of the primary cilium (1, 2), a highly specialized microtubule-based sensory organelle that [...]
- Published
- 2020
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