A microtubule-binding myosin required for nuclear anchoring and spindle assembly.
Proper spindle positioning and orientation are essential for asymmetric cell division and require microtubule-actin filament (F-actin) interactions in many systems. Such interactions are particularly important in meiosis, where they mediate nuclear anchoring, as well as meiotic spindle assembly and rotation, two processes required for asymmetric cell division. Myosin-10 proteins are phosphoinositide-binding, actin-based motors that contain carboxy-terminal MyTH4 and FERM domains of unknown function. Here we show that Xenopus laevis myosin-10 (Myo10) associates with microtubules in vitro and in vivo, and is concentrated at the point where the meiotic spindle contacts the F-actin-rich cortex. Microtubule association is mediated by the MyTH4-FERM domains, which bind directly to purified microtubules. Disruption of Myo10 function disrupts nuclear anchoring, spindle assembly and spindle-F-actin association. Thus, this myosin has a novel and critically important role during meiosis in integrating the F-actin and microtubule cytoskeletons.
Weber
Kari L
KL
Department of Zoology, University of Wisconsin, Madison, Madison, Wisconsin 53706, USA.
Sokac
Anna M
AM
Berg
Jonathan S
JS
Cheney
Richard E
RE
Bement
William M
WM
D000199:Actins / Q000378:metabolism; D000818:Animals; D002467:Cell Nucleus / Q000737:chemistry / Q000378:metabolism*; D008540:Meiosis / Q000502:physiology*; D008870:Microtubules / Q000737:chemistry / Q000378:metabolism*; D009218:Myosins / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D008941:Spindle Apparatus / Q000737:chemistry* / Q000378:metabolism*; D029867:Xenopus Proteins / Q000737:chemistry / Q000378:metabolism*; D014982:Xenopus laevis
D000199:Actins; C492069:Myo10 protein, Xenopus; D029867:Xenopus Proteins; D009218:Myosins