Cep169, a Novel Microtubule Plus-End-Tracking Centrosomal Protein, Binds to CDK5RAP2 and Regulates Microtubule Stability

PLoS One. 2015 Oct 20;10(10):e0140968. doi: 10.1371/journal.pone.0140968. eCollection 2015.

Abstract

The centrosomal protein, CDK5RAP2, is a microcephaly protein that regulates centrosomal maturation by recruitment of a γ-tubulin ring complex (γ-TuRC) onto centrosomes. In this report, we identified a novel human centrosomal protein, Cep169, as a binding partner of CDK5RAP2, a member of microtubule plus-end-tracking proteins (+TIPs). Cep169 interacts directly with CDK5RAP2 through CM1, an evolutionarily conserved domain, and colocalizes at the pericentriolar matrix (PCM) around centrioles with CDK5RAP2. In addition, Cep169 interacts with EB1 through SxIP-motif responsible for EB1 binding, and colocalizes with CDK5RAP2 at the microtubule plus-end. EB1-binding-deficient Cep169 abolishes EB1 interaction and microtubule plus-end attachment, indicating Cep169 as a novel member of +TIPs. We further show that ectopic expression of either Cep169 or CDK5RAP2 induces microtubule bundling and acetylation in U2OS cells, and depletion of Cep169 induces microtubule depolymerization in HeLa cells, although Cep169 is not required for assembly of γ-tubulin onto centrosome by CDK5RAP2. These results show that Cep169 targets microtubule tips and regulates stability of microtubules with CDK5RAP2.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Cycle Proteins / metabolism*
  • Centrosome / metabolism*
  • HeLa Cells
  • Humans
  • Intracellular Signaling Peptides and Proteins / metabolism*
  • Microtubule-Organizing Center / metabolism*
  • Microtubules / metabolism*
  • Nerve Tissue Proteins / metabolism*
  • Protein Binding
  • Tubulin / metabolism

Substances

  • CDK5RAP2 protein, human
  • Cell Cycle Proteins
  • Intracellular Signaling Peptides and Proteins
  • NCKAP5L protein, human
  • Nerve Tissue Proteins
  • Tubulin

Grants and funding

Grant-in-Aid for Scientific Research on Priority Areas. Grants-in-Aid for Scientific Research is a competitive research sponsored by Ministry of Education, Culture, Sports, Science and Technology (MEXT) and Japan Society for the Promotion of Science (JSPS) to promote research across a wide variety of fields, ranging from the humanities and social sciences to the natural sciences. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.