Rho and anillin-dependent control of mDia2 localization and function in cytokinesis.
Diaphanous-related formin, mDia, is an actin nucleation/polymerization factor functioning downstream of the small GTPase Rho. Although Rho is critically involved in cytokinesis, it remains elusive how Rho effectors and other regulators of cytoskeletons work together to accomplish this process. Here we focused on mDia2, an mDia isoform involved in cytokinesis of NIH 3T3 cells, and analyzed mechanisms of its localization in cytokinesis. We found that targeting of mDia2 to the cleavage furrow requires not only its binding to RhoA but also its diaphanous-inhibitory domain (DID). We then performed pulldown assays using a fragment containing the latter domain as a bait and identified anillin as a novel mDia2 interaction partner. The anillin-binding is competitive with the diaphanous autoregulatory domain (DAD) of mDia2 in its autoinhibitory interaction. A series of RNA interference and functional rescue experiments has revealed that, in addition to the Rho GTPase-mediated activation, the interaction between mDia2 and anillin is required for the localization and function of mDia2 in cytokinesis.
Watanabe
Sadanori
S
Department of Pharmacology, Kyoto University Faculty of Medicine, Kyoto, Japan.
Okawa
Katsuya
K
Miki
Takashi
T
Sakamoto
Satoko
S
Morinaga
Tomoko
T
Segawa
Kohei
K
Arakawa
Takatoshi
T
Kinoshita
Makoto
M
Ishizaki
Toshimasa
T
Narumiya
Shuh
S
D000818:Animals; D003285:Contractile Proteins / Q000235:genetics / Q000378:metabolism*; D048749:Cytokinesis / Q000502:physiology*; D006367:HeLa Cells; D006801:Humans; D051379:Mice; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism*; D009252:NADPH Dehydrogenase / Q000235:genetics / Q000378:metabolism*; D041681:NIH 3T3 Cells; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism*; D034622:RNA Interference; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D020741:rho GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*
D003285:Contractile Proteins; D008869:Microtubule-Associated Proteins; D020033:Protein Isoforms; D011993:Recombinant Fusion Proteins; C095886:anillin; C508552:Dia2 protein, mouse; D009252:NADPH Dehydrogenase; D020741:rho GTP-Binding Proteins