Characterization of the CLASP2 Protein Interaction Network Identifies SOGA1 as a Microtubule-Associated Protein

Mol Cell Proteomics. 2017 Oct;16(10):1718-1735. doi: 10.1074/mcp.RA117.000011. Epub 2017 May 26.


CLASP2 is a microtubule-associated protein that undergoes insulin-stimulated phosphorylation and co-localization with reorganized actin and GLUT4 at the plasma membrane. To gain insight to the role of CLASP2 in this system, we developed and successfully executed a streamlined interactome approach and built a CLASP2 protein network in 3T3-L1 adipocytes. Using two different commercially available antibodies for CLASP2 and an antibody for epitope-tagged, overexpressed CLASP2, we performed multiple affinity purification coupled with mass spectrometry (AP-MS) experiments in combination with label-free quantitative proteomics and analyzed the data with the bioinformatics tool Significance Analysis of Interactome (SAINT). We discovered that CLASP2 coimmunoprecipitates (co-IPs) the novel protein SOGA1, the microtubule-associated protein kinase MARK2, and the microtubule/actin-regulating protein G2L1. The GTPase-activating proteins AGAP1 and AGAP3 were also enriched in the CLASP2 interactome, although subsequent AGAP3 and CLIP2 interactome analysis suggests a preference of AGAP3 for CLIP2. Follow-up MARK2 interactome analysis confirmed reciprocal co-IP of CLASP2 and revealed MARK2 can co-IP SOGA1, glycogen synthase, and glycogenin. Investigating the SOGA1 interactome confirmed SOGA1 can reciprocal co-IP both CLASP2 and MARK2 as well as glycogen synthase and glycogenin. SOGA1 was confirmed to colocalize with CLASP2 and with tubulin, which identifies SOGA1 as a new microtubule-associated protein. These results introduce the metabolic function of these proposed novel protein networks and their relationship with microtubules as new fields of cytoskeleton-associated protein biology.

MeSH terms

  • 3T3 Cells / metabolism
  • Adipocytes / metabolism
  • Animals
  • Autophagy-Related Proteins
  • Computer Simulation
  • GTP-Binding Proteins / genetics
  • GTP-Binding Proteins / metabolism
  • GTPase-Activating Proteins / genetics
  • GTPase-Activating Proteins / metabolism
  • Glucosyltransferases / metabolism
  • Glycogen / metabolism
  • Glycoproteins / metabolism
  • Humans
  • Intracellular Signaling Peptides and Proteins / genetics
  • Intracellular Signaling Peptides and Proteins / metabolism*
  • Mice
  • Mice, Inbred C57BL
  • Microtubule-Associated Proteins / genetics
  • Microtubule-Associated Proteins / metabolism*
  • Protein Interaction Maps*
  • Proteomics


  • AGAP1 protein, mouse
  • Autophagy-Related Proteins
  • CLASP2 protein, mouse
  • GTPase-Activating Proteins
  • Glycoproteins
  • Intracellular Signaling Peptides and Proteins
  • Microtubule-Associated Proteins
  • glycogenin
  • suppressor of glucose by autophagy protein, mouse
  • Glycogen
  • Glucosyltransferases
  • AGAP2 protein, human
  • GTP-Binding Proteins

Associated data

  • PDB/4RH7