Identification of tubulin deglutamylase among Caenorhabditis elegans and mammalian cytosolic carboxypeptidases (CCPs)

Item Type:	Article
Title:	Identification of tubulin deglutamylase among Caenorhabditis elegans and mammalian cytosolic carboxypeptidases (CCPs)
Creators Name:	Kimura, Y. and Kurabe, N. and Ikegami, K. and Tsutsumi, K. and Konishi, Y. and Kaplan, O.I. and Kunitomo, H. and Iino, Y. and Blacque, O.E. and Setou, M.
Abstract:	Tubulin polyglutamylation is a reversible post-translational modification, serving important roles in microtubule (MT)-related processes. Polyglutamylases of the tubulin tyrosine ligase-like (TTLL) family add glutamate moieties to specific tubulin glutamate residues, whereas as yet unknown deglutamylases shorten polyglutamate chains. First we investigated regulatory machinery of tubulin glutamylation in MT-based sensory cilia of the roundworm Caenorhabditis elegans. We found that ciliary MTs were polyglutamylated by a process requiring ttll-4. Conversely, loss of ccpp-6 gene function, which encodes one of two cytosolic carboxypeptidases (CCPs), resulted in elevated levels of ciliary MT polyglutamylation. Consistent with a deglutamylase function for ccpp-6, overexpression of this gene in ciliated cells decreased polyglutamylation signals. Similarly, we confirmed that overexpression of murine CCP5, one of two sequence orthologs of nematode ccpp-6, caused a dramatic loss of MT polyglutamylation in cultured mammalian cells. Finally, using an in vitro assay for tubulin glutamylation, we found that recombinantly expressed Myc-tagged CCP5 exhibited deglutamylase biochemical activities. Together, these data from two evolutionarily divergent systems identify C. elegans CCPP-6 and its mammalian ortholog CCP5 as a tubulin deglutamylase.
Keywords:	C. Elegans, Carboxypeptidase, Microtubules, Post-Translational Modification, Tubulin, Cilia, Polyglutamylation, Animals, Mice, Caenorhabditis elegans
Source:	Journal of Biological Chemistry
ISSN:	0021-9258
Publisher:	American Society for Biochemistry and Molecular Biology
Volume:	285
Number:	30
Page Range:	22936-22941
Date:	23 July 2010
Official Publication:	https://doi.org/10.1074/jbc.C110.128280
PubMed:	View item in PubMed

Repository Staff Only: item control page