The PN2-3 Domain of Centrosomal P4.1-associated Protein Implements a Novel Mechanism for Tubulin Sequestration - CNRS - Centre national de la recherche scientifique Accéder directement au contenu
Article Dans Une Revue Journal of Biological Chemistry Année : 2009

The PN2-3 Domain of Centrosomal P4.1-associated Protein Implements a Novel Mechanism for Tubulin Sequestration

Résumé

Microtubules are cytoskeletal components involved in multiple cell functions such as mitosis, motility, or intracellular traffic. In vivo, these polymers made of alphabeta-tubulin nucleate mostly from the centrosome to establish the interphasic microtubule network or, during mitosis, the mitotic spindle. Centrosomal P4.1-associated protein (CPAP; also named CENPJ) is a centrosomal protein involved in the assembly of centrioles and important for the centrosome function. This protein contains a microtubule-destabilizing region referred to as PN2-3. Here we decrypt the microtubule destabilization activity of PN2-3 at the molecular level and show that it results from the sequestration of tubulin by PN2-3 in a non-polymerizable 1:1 complex. We also map the tubulin/PN2-3 interaction both on the PN2-3 sequence and on the tubulin surface. NMR and CD data on free PN2-3 in solution show that this is an intrinsically unstructured protein that comprises a 23-amino acid residue alpha-helix. This helix is embedded in a 76-residue region that interacts strongly with tubulin. The interference of PN2-3 with well characterized tubulin properties, namely GTPase activity, nucleotide exchange, vinblastine-induced self-assembly, and stathmin family protein binding, highlights the beta subunit surface located at the intermolecular longitudinal interface when tubulin is embedded in a microtubule as a tubulin/PN2-3 interaction area. These findings characterize the PN2-3 fragment of CPAP as a protein with an unprecedented tubulin sequestering mechanism distinct from that of stathmin family proteins.

Dates et versions

hal-02120593 , version 1 (06-05-2019)

Identifiants

Citer

Anthony Cormier, Marie-Jeanne Clément, Marcel Knossow, Sylvie Lachkar, Philippe Savarin, et al.. The PN2-3 Domain of Centrosomal P4.1-associated Protein Implements a Novel Mechanism for Tubulin Sequestration. Journal of Biological Chemistry, 2009, 284 (11), pp.6909-6917. ⟨10.1074/jbc.M808249200⟩. ⟨hal-02120593⟩
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