Modulation of cell adhesion and migration by the histone methyltransferase subunit mDpy-30 and its interacting proteins

PLoS One. 2010 Jul 23;5(7):e11771. doi: 10.1371/journal.pone.0011771.

Abstract

We have previously shown that a subset of mDpy-30, an accessory subunit of the nuclear histone H3 lysine 4 methyltransferase (H3K4MT) complex, also localizes at the trans-Golgi network (TGN), where its recruitment is mediated by the TGN-localized ARF guanine nucleotide exchange factor (ArfGEF) BIG1. Depletion of mDpy-30 inhibits the endosome-to-TGN transport of internalized CIMPR receptors and concurrently promotes their accumulation at the cell protrusion. These observations suggest mDpy-30 may play a novel role at the crossroads of endosomal trafficking, nuclear transcription and adhesion/migration. Here we provide novel mechanistic and functional insight into this association. First, we demonstrate a direct interaction between mDpy-30 and BIG1 and locate the binding region in the N-terminus of BIG1. Second, we provide evidence that the depletion or overexpression of mDpy-30 enhances or inhibits cellular adhesion/migration of glioma cells in vitro, respectively. A similar increase in cell adhesion/migration is observed in cells with reduced levels of BIG1 or other H3K4MT subunits. Third, knockdown of mDpy-30, BIG1, or the RbBP5 H3K4MT subunit increases the targeting of beta1 integrin to cell protrusions, and suppression of H3K4MT activity by depleting mDpy-30 or RbBP5 leads to increased protein and mRNA levels of beta1 integrin. Moreover, stimulation of cell adhesion/migration via mDpy-30 knockdown is abolished after treating cells with a function-blocking antibody to beta1 integrin. Taken together, these data indicate that mDpy-30 and its interacting proteins function as a novel class of cellular adhesion/migration modulators partially by affecting the subcellular distribution of endosomal compartments as well as the expression of key adhesion/migration proteins such as beta1 integrin.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Blotting, Western
  • Cell Adhesion / genetics
  • Cell Adhesion / physiology*
  • Cell Line
  • Cell Line, Tumor
  • Cell Movement / genetics
  • Cell Movement / physiology*
  • Electrophoresis, Polyacrylamide Gel
  • Fluorescent Antibody Technique
  • Guanine Nucleotide Exchange Factors / genetics
  • Guanine Nucleotide Exchange Factors / metabolism
  • HeLa Cells
  • Histone Methyltransferases
  • Histone-Lysine N-Methyltransferase / genetics
  • Histone-Lysine N-Methyltransferase / metabolism*
  • Humans
  • Immunoprecipitation
  • Integrin beta1 / genetics
  • Integrin beta1 / metabolism
  • Lentivirus / genetics
  • Microscopy
  • Microscopy, Confocal
  • Polymerase Chain Reaction
  • Protein Binding
  • Receptor, IGF Type 2
  • Receptors, Cytoplasmic and Nuclear / genetics
  • Receptors, Cytoplasmic and Nuclear / metabolism
  • rab GTP-Binding Proteins / genetics
  • rab GTP-Binding Proteins / metabolism
  • rab4 GTP-Binding Proteins / genetics
  • rab4 GTP-Binding Proteins / metabolism
  • trans-Golgi Network / metabolism

Substances

  • ARFGEF1 protein, human
  • Guanine Nucleotide Exchange Factors
  • Integrin beta1
  • Receptor, IGF Type 2
  • Receptors, Cytoplasmic and Nuclear
  • cation-dependent mannose-6-phosphate receptor
  • Histone Methyltransferases
  • Histone-Lysine N-Methyltransferase
  • rab11 protein
  • rab GTP-Binding Proteins
  • rab4 GTP-Binding Proteins