title: Modulation of cell adhesion and migration by the histone methyltransferase subunit mDpy-30 and its interacting proteins.
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.
authors.affiliation: Department of Pediatrics, Sichuan University, West China Second University Hospital, Chengdu, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Xia
authors.forename: Alexandra
authors.initials: A
authors.lastname: Joubert
authors.forename: Benjamin
authors.initials: B
authors.lastname: Groves
authors.forename: Kevin
authors.initials: K
authors.lastname: Vo
authors.forename: Davin
authors.initials: D
authors.lastname: Ashraf
authors.forename: Derek
authors.initials: D
authors.lastname: Djavaherian
authors.forename: Jason
authors.initials: J
authors.lastname: Awe
authors.forename: Ying
authors.initials: Y
authors.lastname: Xiong
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Cherfils
authors.forename: Dzwokai
authors.initials: D
authors.lastname: Ma
mesh_terms: D015153:Blotting, Western; D002448:Cell Adhesion / Q000235:genetics / Q000502:physiology*; D002460:Cell Line; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000235:genetics / Q000502:physiology*; D004591:Electrophoresis, Polyacrylamide Gel; D005455:Fluorescent Antibody Technique; D020662:Guanine Nucleotide Exchange Factors / Q000235:genetics / Q000378:metabolism; D006367:HeLa Cells; D000076983:Histone Methyltransferases; D011495:Histone-Lysine N-Methyltransferase / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D047468:Immunoprecipitation; D019012:Integrin beta1 / Q000235:genetics / Q000378:metabolism; D016086:Lentivirus / Q000235:genetics; D008853:Microscopy; D018613:Microscopy, Confocal; D016133:Polymerase Chain Reaction; D011485:Protein Binding; D017527:Receptor, IGF Type 2; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics / Q000378:metabolism; D020691:rab GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism; D020695:rab4 GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism; D021601:trans-Golgi Network / Q000378:metabolism; D000099193:rab11 GTP-Binding Proteins
chemical_list: D020662:Guanine Nucleotide Exchange Factors; D000076983:Histone Methyltransferases; D011495:Histone-Lysine N-Methyltransferase; D019012:Integrin beta1; D017527:Receptor, IGF Type 2; D018160:Receptors, Cytoplasmic and Nuclear; D020691:rab GTP-Binding Proteins; D020695:rab4 GTP-Binding Proteins; D000099193:rab11 GTP-Binding Proteins; C119087:ARFGEF1 protein, human; C034304:cation-dependent mannose-6-phosphate receptor