Interaction of Skp1 with CENP-E at the midbody is essential for cytokinesis

Biochem Biophys Res Commun. 2006 Jun 23;345(1):394-402. doi: 10.1016/j.bbrc.2006.04.062. Epub 2006 Apr 25.

Abstract

Centromere-associated protein E (CENP-E) is a kinesin-related microtubule motor protein that is essential for chromosome congression during mitosis. Our previous studies show that microtubule motor CENP-E represents a link between attachment of spindle microtubules and the mitotic checkpoint signaling cascade. However, the molecular function of CENP-E at the midbody had remained elusive. Here we show that CENP-E interacts with Skp1 at the midbody and participates in cytokinesis. CENP-E interacts with Skp1 in vitro and in vivo via its coiled-coil domain. Our yeast two-hybrid assays mapped the binding interfaces to the central stalk region of CENP-E (955-1571 aa) and the C-terminal 33 amino acids of Skp1, respectively. Our immunocytochemical studies revealed that CENP-E targets to the midbody prior to Skp1 and the midbody localization of CENP-E becomes diminished as Skp1 arrives at the midbody. Suppression of Skp1 in mitotic HeLa cells by siRNA resulted in accumulation of telophase cells with elongated inter-cell bridges and with midbodies stretched 2-3 times longer than that of normal cells. These Skp1-eliminated or -suppressed cells accumulate higher level of CENP-E, suggesting that spatiotemporal regulation of CENP-E degradation at the midbody is essential for cytokinesis. Over-expression of Skp1 lacking the CENP-E-binding domain confirmed that Skp1-CENP-E interaction is essential for faithful cytokinesis. We hypothesize that CENP-E degradation is essential for faithful mitotic exit and the proteolysis of CENP-E is mediated by SCF via a direct Skp1 link.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Cycle Proteins / metabolism*
  • Centrosome / metabolism*
  • Chromosomal Proteins, Non-Histone / metabolism*
  • Cytokinesis / physiology*
  • Molecular Motor Proteins / physiology*
  • Protein Binding
  • Protein Interaction Mapping
  • S-Phase Kinase-Associated Proteins / metabolism*

Substances

  • Cell Cycle Proteins
  • Chromosomal Proteins, Non-Histone
  • Molecular Motor Proteins
  • S-Phase Kinase-Associated Proteins
  • centromere protein E