Phosphoregulation of the RNA-binding protein Hu antigen R (HuR) by Cdk5 affects centrosome function

J Biol Chem. 2012 Sep 14;287(38):32277-87. doi: 10.1074/jbc.M112.353912. Epub 2012 Jul 24.

Abstract

Hu antigen R (HuR) is an mRNA-binding protein belonging to the ELAV family. It is highly expressed in cancer and involved in cell survival and proliferation. The impact of post-translational regulation of HuR and resulting cellular effects are poorly understood. In the current report, we describe a direct interaction between HuR and Cdk5 in glioma. We determined that Cdk5 specifically phosphorylates HuR at the serine 202 residue in the unique hinge region. The molecular consequences of this interaction are an altered HuR ability to bind, stabilize, and promote translation of mRNAs. At the cellular level, the anomalous HuR phosphorylation at this site evokes robust defects in centrosome duplication and cohesion as well as arrest of cell cycle progression. Subcellular fractionation and immunofluorescence technique confirm a direct integration of HuR and Cdk5 with centrosomes. We propose that HuR stores mRNA in the centrosome and that HuR phosphorylation by Cdk5 controls de novo protein synthesis in near proximity to centrosomes and, thus, impacts centrosome function.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Brain Neoplasms / metabolism
  • Cell Cycle
  • Cell Line, Tumor
  • Centrosome / ultrastructure*
  • Cyclin A / chemistry
  • Cyclin-Dependent Kinase 5 / chemistry*
  • Cytoplasm / metabolism
  • ELAV Proteins / chemistry*
  • ELAV Proteins / metabolism
  • Gene Expression Regulation, Neoplastic
  • Glioma / metabolism
  • Humans
  • Microscopy, Fluorescence / methods
  • Phosphorylation
  • RNA, Messenger / metabolism
  • Serine / chemistry

Substances

  • Cyclin A
  • ELAV Proteins
  • RNA, Messenger
  • Serine
  • Cyclin-Dependent Kinase 5
  • CDK5 protein, human