Dysfunction of the ciliary ARMC9/TOGARAM1 protein module causes Joubert syndrome.

TitleDysfunction of the ciliary ARMC9/TOGARAM1 protein module causes Joubert syndrome.
Publication TypeJournal Article
Year of Publication2020
AuthorsLatour, BL, Van De Weghe, JC, Rusterholz, TDs, Letteboer, SJf, Gomez, A, Shaheen, R, Gesemann, M, Karamzade, A, Asadollahi, M, Barroso-Gil, M, Chitre, M, Grout, ME, van Reeuwijk, J, van Beersum, SEc, Miller, CV, Dempsey, JC, Morsy, H, Bamshad, MJ, Nickerson, DA, Neuhauss, SCf, Boldt, K, Ueffing, M, Keramatipour, M, Sayer, JA, Alkuraya, FS, Bachmann-Gagescu, R, Roepman, R, Doherty, D
Corporate AuthorsUniversity of Washington Center for Mendelian Genomics, Genomics England Research Consortium
JournalJ Clin Invest
Date Published2020 08 03
KeywordsAbnormalities, Multiple, Acetylation, Animals, Armadillo Domain Proteins, Cerebellum, Cilia, CRISPR-Cas Systems, Disease Models, Animal, Eye Abnormalities, Humans, Kidney Diseases, Cystic, Peptides, Retina, Zebrafish, Zebrafish Proteins

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.

Alternate JournalJ Clin Invest
PubMed ID32453716
PubMed Central IDPMC7410078
Grant ListU54 HG006493 / HG / NHGRI NIH HHS / United States
U54 HD083091 / HD / NICHD NIH HHS / United States
F32 HD095599 / HD / NICHD NIH HHS / United States
P50 HD103524 / HD / NICHD NIH HHS / United States
/ DH / Department of Health / United Kingdom
K99 HD100554 / HD / NICHD NIH HHS / United States
UM1 HG006493 / HG / NHGRI NIH HHS / United States
R01 NS064077 / NS / NINDS NIH HHS / United States