Novel interactors and a role for supervillin in early cytokinesis

Cytoskeleton (Hoboken). 2010 Jun;67(6):346-64. doi: 10.1002/cm.20449.

Abstract

Supervillin, the largest member of the villin/gelsolin/flightless family, is a peripheral membrane protein that regulates each step of cell motility, including cell spreading. Most known interactors bind within its amino (N)-terminus. We show here that the supervillin carboxy (C)-terminus can be modeled as supervillin-specific loops extending from gelsolin-like repeats plus a villin-like headpiece. We have identified 27 new candidate interactors from yeast two-hybrid screens. The interacting sequences from 12 of these proteins (BUB1, EPLIN/LIMA1, FLNA, HAX1, KIF14, KIFC3, MIF4GD/SLIP1, ODF2/Cenexin, RHAMM, STARD9/KIF16A, Tks5/SH3PXD2A, TNFAIP1) co-localize with and mis-localize EGFP-supervillin in mammalian cells, suggesting associations in vivo. Supervillin-interacting sequences within BUB1, FLNA, HAX1, and MIF4GD also mimic supervillin over-expression by inhibiting cell spreading. Most new interactors have known roles in supervillin-associated processes, e.g. cell motility, membrane trafficking, ERK signaling, and matrix invasion; three (KIF14, KIFC3, STARD9/KIF16A) have kinesin motor domains; and five (EPLIN, KIF14, BUB1, ODF2/cenexin, RHAMM) are important for cell division. GST fusions of the supervillin G2-G3 or G4-G6 repeats co-sediment KIF14 and EPLIN, respectively, consistent with a direct association. Supervillin depletion leads to increased numbers of bi- and multi-nucleated cells. Cytokinesis failure occurs predominately during early cytokinesis. Supervillin localizes with endogenous myosin II and EPLIN in the cleavage furrow, and overlaps with the oncogenic kinesin, KIF14, at the midbody. We conclude that supervillin, like its interactors, is important for efficient cytokinesis. Our results also suggest that supervillin and its interaction partners coordinate actin and microtubule motor functions throughout the cell cycle.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Biological Assay
  • COS Cells
  • Cattle
  • Cell Proliferation
  • Chlorocebus aethiops
  • Cytokinesis*
  • Cytoskeletal Proteins / metabolism
  • Gene Knockdown Techniques
  • Green Fluorescent Proteins / metabolism
  • HeLa Cells
  • Humans
  • Membrane Proteins / chemistry
  • Membrane Proteins / metabolism*
  • Microfilament Proteins / chemistry
  • Microfilament Proteins / metabolism*
  • Myosin Type II / metabolism
  • Protein Binding
  • Protein Structure, Secondary
  • Protein Transport
  • Recombinant Fusion Proteins / isolation & purification
  • Recombinant Fusion Proteins / metabolism

Substances

  • Cytoskeletal Proteins
  • LIMA1 protein, human
  • Membrane Proteins
  • Microfilament Proteins
  • Recombinant Fusion Proteins
  • SVIL protein, human
  • enhanced green fluorescent protein
  • Green Fluorescent Proteins
  • Myosin Type II