Caenorhabditis elegansglutamylating enzymes function redundantly in male mating

Abstract

Microtubule glutamylation is an important modulator of microtubule function and has been implicated in the regulation of centriole stability, neuronal outgrowth and cilia motility. Glutamylation of the microtubules is catalyzed by a family of tubulin tyrosine ligase-like (TTLL) enzymes. Analysis of individual TTLL enzymes has led to an understanding of their specific functions, but how activities of the TTLL enzymes are coordinated to spatially and temporally regulate glutamylation remains relatively unexplored. We have undertaken an analysis of the glutamylating TTLL enzymes in C. elegans. We find that although all five TTLL enzymes are expressed in the embryo and adult worm, loss of individual enzymes does not perturb microtubule function in embryonic cell divisions. Moreover, normal dye-filling, osmotic avoidance and male mating behavior indicate the presence of functional amphid cilia and male-specific neurons. A ttll-4(tm3310); ttll-11(tm4059); ttll-5(tm3360) triple mutant, however, shows reduced male mating efficiency due to a defect in the response step, suggesting that these three enzymes function redundantly, and that glutamylation is required for proper function of the male-specific neurons.

Mutation of NEKL-4/NEK10 and TTLL genes suppress neuronal ciliary degeneration caused by loss of CCPP-1 deglutamylase function

“…The C . elegans genome encodes five TTLL glutamylases— ttll-4 , ttll-5 , ttll-9 , ttll-11 , and ttll-15 [ 6 , 28 ]. We previously showed that ttll-4 mutation suppresses the ccpp-1 Dyf defect, suggesting that TTLL-4 glutamylates microtubules in amphid and phasmid cilia [ 21 ].…”

Environmental responsiveness of tubulin glutamylation in sensory cilia is regulated by the p38 MAPK pathway

“…The avoidance behaviour towards high osmolality is one of the best-characterised sensory behaviours of C. elegans 27 . Since ttll-4 -deficient worms showed subtle defects of avoidance behaviour towards high osmolality 28 , the assay was sensitized using as low as 2 M NaCl solutions (Supplementary Fig. S9 ).…”

The Emerging Roles of Axonemal Glutamylation in Regulation of Cilia Architecture and Functions

“…Typically, three strategies are used to study tubulin glutamylation: (1) genetic perturbation of genes that encode glutamylation-modifying enzymes, (2) manipulation of the glutamylation levels of purified microtubules by recombinant enzymes in vitro , and (3) introduction of specific antibodies to mask the glutamylated motifs of microtubules. Although all of the above experiments imply that glutamylation is important for the structural integrity and functions of cilia ( Gaertig and Wloga, 2008 ; Konno et al, 2012 ; Grau et al, 2013 ; Pathak et al, 2014 ; Chawla et al, 2016 ), these conventional methods have several limitations.…”

“…Moreover, the localization of TTLL7 in cilia of transfected MDCK cells also implies that it has a role in ciliary glutamylation, although more studies are required to confirm this (Van Dijk et al, 2007). Janke et al, 2005;Van Dijk et al, 2007;Wloga et al, 2008;Vogel et al, 2010;Pathak et al, 2011;Ye et al, 2018;Lan et al, Van Dijk et al, 2007;Kashiwaya et al, 2010;Kimura et al, 2010;Lacroix et al, 2010;Rogowski et al, 2010;O'Hagan et al, 2011;Pathak et al, 2011;Ye et al, 2014;Casanova et al, 2015;Chawla et al, 2016;Ijaz et al, 2017;Kimura et al, 2018;Ye et al, 2018;Mahalingan et al,…”