Neuronal apoptosis inhibitory protein (NAIP) localizes to the cytokinetic machinery during cell division

Sci Rep. 2017 Jan 6:7:39981. doi: 10.1038/srep39981.

Abstract

The neuronal apoptosis inhibitory protein (NAIP) is a constituent of the inflammasome and a key component of the innate immune system. Here we use immunofluorescence to position NAIP within the cytokinetic apparatus, contiguous to chromosomal passenger complex (CPC), Centralspindlin, PRC1 and KIF4A. During metaphase, NAIP accumulates in the mitotic spindle poles and is shown in spindle microtubules; in anaphase NAIP is detected in the middle of the central spindle. At the end of cytokinesis, NAIP is localized in the outlying region of the stem body, the center of the intercellular bridge formed between daughter cells prior to cellular abscission. We also describe the sustained presence of NAIP mRNA and protein throughout the cell cycle with a significant increase observed in the G2/M phase. Consistent with a role for NAIP in cytokinesis, NAIP overexpression in HeLa cells promotes the acquisition of a multinuclear phenotype. Conversely, NAIP siRNA gene silencing results in an apoptotic lethal phenotype. Our confocal and super resolution stimulated-emission-depletion (STED) examination of mammalian cell cytokinesis demonstrate a potential new role for NAIP in addition to anti-apoptotic and innate immunology functions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Cycle Proteins / metabolism
  • Cell Survival
  • Cytokinesis*
  • HeLa Cells
  • Humans
  • Kinesins / metabolism
  • Microscopy, Confocal
  • Mitosis
  • Neuronal Apoptosis-Inhibitory Protein / genetics*
  • Neuronal Apoptosis-Inhibitory Protein / metabolism*
  • Phenotype
  • Spindle Apparatus / metabolism*
  • Spindle Poles / metabolism
  • Up-Regulation

Substances

  • Cell Cycle Proteins
  • NAIP protein, human
  • Neuronal Apoptosis-Inhibitory Protein
  • PRC1 protein, human
  • KIF4A protein, human
  • Kinesins

Grants and funding