title: Memo mediates ErbB2-driven cell motility.
abstract: Clinical studies have revealed that cancer patients whose tumours have increased ErbB2 expression tend to have more aggressive, metastatic disease, which is associated with parameters predicting a poor outcome. The molecular basis underlying ErbB2-dependent cell motility and metastases formation, however, still remains poorly understood. In this study, we show that activation of a set of signalling molecules, including MAPK, phosphatidylinositol-3-OH kinase (PI(3)K) and Src, is required for Neu/ErbB2-dependent lamellipodia formation and for motility of breast carcinoma cells. Stimulation of these molecules, however, failed to induce efficient cell migration in the absence of Neu/ErbB2 phosphorylation at Tyr 1201 or Tyr 1227. We describe a novel molecule, Memo (mediator of ErbB2-driven cell motility), that interacts with a phospho-Tyr 1227-containing peptide, most probably through the Shc adaptor protein. After Neu/ErbB2 activation, Memo-defective cells form actin fibres and grow lamellipodia, but fail to extend microtubules towards the cell cortex. Our data suggest that Memo controls cell migration by relaying extracellular chemotactic signals to the microtubule cytoskeleton.
authors.affiliation: Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, CH-4058 Basel, Switzerland.
authors.forename: Romina
authors.initials: R
authors.lastname: Marone
authors.forename: Daniel
authors.initials: D
authors.lastname: Hess
authors.forename: David
authors.initials: D
authors.lastname: Dankort
authors.forename: William J
authors.initials: WJ
authors.lastname: Muller
authors.forename: Nancy E
authors.initials: NE
authors.lastname: Hynes
authors.forename: Ali
authors.initials: A
authors.lastname: Badache
mesh_terms: D008841:Actin Cytoskeleton / Q000378:metabolism; D002352:Carrier Proteins / Q000378:metabolism*; D002465:Cell Movement / Q000502:physiology*; D006801:Humans; D008565:Membrane Proteins / Q000302:isolation & purification / Q000378:metabolism*; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D009361:Neoplasm Invasiveness / Q000235:genetics*; D009362:Neoplasm Metastasis / Q000235:genetics*; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D010766:Phosphorylation; D011554:Pseudopodia / Q000378:metabolism; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics*; D014407:Tumor Cells, Cultured; D019061:src-Family Kinases / Q000378:metabolism
chemical_list: D002352:Carrier Proteins; D008565:Membrane Proteins; D020928:Mitogen-Activated Protein Kinases; D019869:Phosphatidylinositol 3-Kinases; D018719:Erb-b2 Receptor Tyrosine Kinases; D019061:src-Family Kinases