title: DOC-2/DAB2 is the binding partner of myosin VI.
abstract: 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.
authors.affiliation: Department of Physiology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, Massachusetts 01655-0127, USA.
authors.forename: Akira
authors.initials: A
authors.lastname: Inoue
authors.forename: Osamu
authors.initials: O
authors.lastname: Sato
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Homma
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Ikebe
mesh_terms: D008841:Actin Cytoskeleton / Q000502:physiology / Q000648:ultrastructure; D048868:Adaptor Proteins, Signal Transducing; D033942:Adaptor Proteins, Vesicular Transport; D000251:Adenosine Triphosphatases / Q000378:metabolism; D000818:Animals; D051017:Apoptosis Regulatory Proteins; D016147:Genes, Tumor Suppressor; D006801:Humans; D007700:Kinetics; D051379:Mice; D009068:Movement; D018995:Myosin Heavy Chains / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D011506:Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D025521:Tumor Suppressor Proteins; D020798:Two-Hybrid System Techniques; D015003:Yeasts / Q000235:genetics
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D033942:Adaptor Proteins, Vesicular Transport; D051017:Apoptosis Regulatory Proteins; C102885:DAB2 protein, human; D011506:Proteins; D025521:Tumor Suppressor Proteins; C089785:myosin VI; D000251:Adenosine Triphosphatases; D018995:Myosin Heavy Chains