DOC-2/DAB2 is the binding partner of myosin VI.
Myosin VI is a molecular motor that moves processively along actin filaments and is believed to play a role in cargo movement in cells. Here we found that DOC-2/DAB2, a signaling molecule inhibiting the Ras cascade, binds to myosin VI at the globular tail domain. DOC-2/DAB2 binds stoichiometrically to myosin VI with one molecule per one myosin VI heavy chain. The C-terminal 122 amino acid residues of DOC-2/DAB2, containing the Grb2 binding site, is identified to be critical for the binding to myosin VI. Actin gliding assay revealed that the binding of DOC-2/DAB2 to myosin VI can support the actin filament gliding by myosin VI, suggesting that it can function as a myosin VI anchoring molecule. The C-terminal domain but not the N-terminal domain of DOC-2/DAB2 functions as a myosin VI anchoring site. The present findings suggest that myosin VI plays a role in transporting DOC-2/DAB2, a Ras cascade signaling molecule, thus involved in Ras signaling pathways.
Pubmed ID: 11906161 RIS Download
Actin Cytoskeleton | Adaptor Proteins, Signal Transducing | Adaptor Proteins, Vesicular Transport | Adenosine Triphosphatases | Animals | Genes, Tumor Suppressor | Humans | Kinetics | Mice | Movement | Myosin Heavy Chains | Protein Structure, Tertiary | Proteins | Signal Transduction | Tumor Suppressor Proteins | Two-Hybrid System Techniques | Yeasts