A-kinase Anchoring Protein 79/150 Recruits Protein Kinase C to Phosphorylate Roundabout Receptors

J Biol Chem. 2015 May 29;290(22):14107-19. doi: 10.1074/jbc.M115.637470. Epub 2015 Apr 16.


Anchoring proteins direct protein kinases and phosphoprotein phosphatases toward selected substrates to control the efficacy, context, and duration of neuronal phosphorylation events. The A-kinase anchoring protein AKAP79/150 interacts with protein kinase A (PKA), protein kinase C (PKC), and protein phosphatase 2B (calcineurin) to modulate second messenger signaling events. In a mass spectrometry-based screen for additional AKAP79/150 binding partners, we have identified the Roundabout axonal guidance receptor Robo2 and its ligands Slit2 and Slit3. Biochemical and cellular approaches confirm that a linear sequence located in the cytoplasmic tail of Robo2 (residues 991-1070) interfaces directly with sites on the anchoring protein. Parallel studies show that AKAP79/150 interacts with the Robo3 receptor in a similar manner. Immunofluorescent staining detects overlapping expression patterns for murine AKAP150, Robo2, and Robo3 in a variety of brain regions, including hippocampal region CA1 and the islands of Calleja. In vitro kinase assays, peptide spot array mapping, and proximity ligation assay staining approaches establish that human AKAP79-anchored PKC selectively phosphorylates the Robo3.1 receptor subtype on serine 1330. These findings imply that anchored PKC locally modulates the phosphorylation status of Robo3.1 in brain regions governing learning and memory and reward.

Keywords: A-kinase-anchoring protein (AKAP); phosphorylation; protein kinase; protein-protein interaction; signal transduction.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • A Kinase Anchor Proteins / metabolism*
  • Animals
  • Brain / metabolism
  • Cytoplasm / metabolism
  • Gene Silencing
  • Glutathione Transferase / metabolism
  • HEK293 Cells
  • Hippocampus / metabolism
  • Humans
  • Ligands
  • Macromolecular Substances
  • Mass Spectrometry
  • Membrane Proteins / metabolism
  • Mice
  • Mice, Transgenic
  • Microscopy, Fluorescence
  • Nerve Tissue Proteins / metabolism
  • Neurons / metabolism
  • Phosphorylation
  • Protein Interaction Mapping
  • Protein Isoforms
  • Protein Kinase C / metabolism*
  • RNA, Small Interfering / metabolism
  • Receptors, Cell Surface
  • Receptors, Immunologic / metabolism*
  • Signal Transduction


  • A Kinase Anchor Proteins
  • AKAP5 protein, human
  • Akap5 protein, mouse
  • Ligands
  • Macromolecular Substances
  • Membrane Proteins
  • Nerve Tissue Proteins
  • Protein Isoforms
  • RNA, Small Interfering
  • ROBO2 protein, human
  • ROBO3 protein, human
  • Receptors, Cell Surface
  • Receptors, Immunologic
  • Robo3 protein, mouse
  • Glutathione Transferase
  • Protein Kinase C