CSAP Acts as a Regulator of TTLL-Mediated Microtubule Glutamylation

Guillaume Bompard (1) , Juliette van Dijk (2) , Julien Cau (1) , Yoann Lannay (1) , Guillaume Marcellin (1) , Aleksandra Lawera (1) , Siem van Der Laan (1) , Krzysztof Rogowski (1)

1 IGH - Institut de génétique humaine
2 CRBM - Centre de recherche en Biologie cellulaire de Montpellier

Tubulin glutamylation is a reversible posttranslational modification that accumulates on stable microtubules (MTs). While abnormally high levels of this modification lead to a number of disorders such as male sterility, retinal degeneration, and neurodegeneration, very little is known about the molecular mechanisms underlying the regulation of glutamylase activity. Here, we found that CSAP forms a complex with TTLL5, and we demonstrate that the two proteins regulate their reciprocal abundance. Moreover, we show that CSAP increases TTLL5-mediated glutamylation and identify the TTLL5-interacting domain. Deletion of this domain leads to complete loss of CSAP activating function without impacting its MT binding. Binding of CSAP to TTLL5 promotes relocalization of TTLL5 toward MTs. Finally, we show that CSAP binds and activates all of the remaining autonomously active TTLL glutamylases. As such, we present CSAP as a major regulator of tubulin glutamylation and associated functions.

Mots clés: tubulin code; severing; posttranslational modification; microtubule dynamics; brain; MAPs

Domaines: Sciences du Vivant [q-bio]; Génétique

Guillaume Bompard, Juliette van Dijk, Julien Cau, Yoann Lannay, Guillaume Marcellin, et al.. CSAP Acts as a Regulator of TTLL-Mediated Microtubule Glutamylation. Cell Reports, 2018, 25 (10), pp.2866-2877.e5. ⟨10.1016/j.celrep.2018.10.095⟩. ⟨hal-01974905⟩