Transforming acidic coiled-coil protein-3 (Tacc3) acts as a negative regulator of Notch signaling through binding to CDC10/Ankyrin repeats

Biochem Biophys Res Commun. 2010 Oct 1;400(4):606-12. doi: 10.1016/j.bbrc.2010.08.111. Epub 2010 Sep 6.


We have identified the transforming acidic coiled-coil protein-3 (Tacc3) as a binding partner for Notch4/Int3 and were able to show that it binds to the intracellular domain (ICD) of all members of the Notch receptor family. Members of the Tacc family reside at the centrosomes and associates with microtubules. Recent studies suggest that Tacc3 also contributes to the regulation of gene transcription. Tacc3 specifically interacts with the Notch4/Int3 CDC10/Ankyrin repeats and to a lesser extent, with residues C-terminal to these repeats in the ICD. Dual label immunofluorescence of mouse mammary tissue shows Tacc3 co-localizes with the Notch3 ICD. Co-immunoprecipitation of endogenous Notch and Tacc3 proteins from NIH3T3 cell extracts, lung and mammary gland confirms that these two proteins interact under physiological conditions. In addition, knock down of Tacc3 in NIH3T3 cells leads to the up-regulation of Hey2, a target gene for Notch signaling. The affinity of Tacc3 binding to Notch4/Int3 ICD is similar to that between Rbpj and Notch4/Int3 ICD. Notch4/Int3 ICD-Tacc3 interaction results in the inhibition of transcription from a Hes1-Luciferase reporter vector in COS-1 cells. The inhibition was reversed in these cells by increasing the levels of Rbpj. Taken together, these results suggest that Tacc3 is a negative regulator of the Notch signaling pathway.

Publication types

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

MeSH terms

  • Animals
  • Ankyrin Repeat*
  • Basic Helix-Loop-Helix Transcription Factors / genetics
  • COS Cells
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism*
  • Chlorocebus aethiops
  • Fetal Proteins / genetics
  • Fetal Proteins / metabolism*
  • Gene Expression Regulation
  • Genes, Reporter
  • Homeodomain Proteins / genetics
  • Luciferases
  • Mice
  • Microtubule-Associated Proteins
  • NIH 3T3 Cells
  • Proto-Oncogene Proteins / metabolism*
  • Receptor, Notch4
  • Receptors, Notch / metabolism*
  • Septins / genetics
  • Septins / metabolism*
  • Signal Transduction
  • Transcription Factor HES-1
  • Two-Hybrid System Techniques


  • Basic Helix-Loop-Helix Transcription Factors
  • Carrier Proteins
  • Fetal Proteins
  • Hes1 protein, mouse
  • Homeodomain Proteins
  • Microtubule-Associated Proteins
  • Proto-Oncogene Proteins
  • Receptor, Notch4
  • Receptors, Notch
  • TACC3 protein, mouse
  • Transcription Factor HES-1
  • Notch4 protein, mouse
  • Luciferases
  • Sept7 protein, mouse
  • Septins