Fig. 4
A balanced enzymatic activity between CCP5 and TTLL5/TTLL6 is critical for maintaining a proper level of axoneme polyglutamylation. Axoneme polyglutamylation was detected by antibody GT335 or polyE. GT335 antibody detects all polyglutamate side chains independently of their length (≥1 glutamates) while polyE antibody is specific to long side chains (≥3 glutamates). a Depletion of CCP5 increased axoneme polyglutamylation and cilia length. Quantification in right panels. b–d Depletion of CCP5 corrected FIP5- (b, siNC: n = 54, siFIP5: n = 42, siFIP5 + siCCP5: n = 49 cilia), TTLL5- (c, n = 50 cilia for each group), or TTLL6- (d, n = 50 cilia for each group) knockdown-induced defective axoneme polyglutamylation as detected by GT335 antibody. Quantification in right panels. e Depletion of CCP5 could not restore long-chain axoneme glutamylation as detected by polyE antibody. Quantification in right panel (n = 50 cilia for each group). f Depletion of CCP5 restored axoneme polyglutamylation in ARL13B-deficient cells as detected by GT335 antibody. Quantification in right panel. Scale bars: 2 μm. Center values represent mean. Error bars represent s.d. N values: cilia number accessed from at least six fields. Statistical significance was determined using unpaired Student’s t test. ** p < 0.01
