EML4 promotes the loading of NUDC to the spindle for mitotic progression

Cell Cycle. 2015;14(10):1529-39. doi: 10.1080/15384101.2015.1026514.

Abstract

Echinoderm microtubule-associated protein (EMAP)-like (EML) family proteins are microtubule-associated proteins that have a conserved hydrophobic EMAP-like protein (HELP) domain and multiple WD40 domains. In this study, we examined the role of EML4, which is a member of the EML family, in cell division. Time-lapse microscopy analysis demonstrated that EML4 depletion induced chromosome misalignment during metaphase and delayed anaphase initiation. Further analysis by immunofluorescence showed that EML4 was required for the organization of the mitotic spindle and for the proper attachment of kinetochores to microtubules. We searched for EML4-associating proteins by mass spectrometry analysis and found that the nuclear distribution gene C (NUDC) protein, which is a critical factor for the progression of mitosis, was associated with EML4. This interaction was mediated by the WD40 repeat of EML4 and by the C-terminus of NUDC. In the absence of EML4, NUDC was no longer able to localize to the mitotic spindle, whereas NUDC was dispensable for EML4 localization. Our results show that EML4 is critical for the loading of NUDC onto the mitotic spindle for mitotic progression.

Keywords: EML4; NUDC; cytokinesis; kinetochore; mitosis; spindle.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Cycle Proteins / antagonists & inhibitors
  • Cell Cycle Proteins / chemistry
  • Cell Cycle Proteins / genetics
  • Cell Cycle Proteins / metabolism*
  • Cold Temperature
  • HeLa Cells
  • Humans
  • Kinetochores / metabolism
  • Microscopy, Confocal
  • Microtubule-Associated Proteins / antagonists & inhibitors
  • Microtubule-Associated Proteins / genetics
  • Microtubule-Associated Proteins / metabolism*
  • Microtubules / metabolism
  • Mitosis*
  • Nuclear Proteins / chemistry
  • Nuclear Proteins / metabolism*
  • Protein Structure, Tertiary
  • RNA Interference
  • RNA, Small Interfering / metabolism
  • Serine Endopeptidases / genetics
  • Serine Endopeptidases / metabolism*
  • Spindle Apparatus / metabolism*
  • Time-Lapse Imaging

Substances

  • Cell Cycle Proteins
  • Microtubule-Associated Proteins
  • NUDC protein, human
  • Nuclear Proteins
  • RNA, Small Interfering
  • EML4 protein, human
  • Serine Endopeptidases