Functional analysis of a human homologue of the Drosophila actin binding protein anillin suggests a role in cytokinesis.
We have characterized a human homologue of anillin, a Drosophila actin binding protein. Like Drosophila anillin, the human protein localizes to the nucleus during interphase, the cortex following nuclear envelope breakdown, and the cleavage furrow during cytokinesis. Anillin also localizes to ectopic cleavage furrows generated between two spindles in fused PtK(1) cells. Microinjection of antianillin antibodies slows cleavage, leading to furrow regression and the generation of multinucleate cells. GFP fusions that contain the COOH-terminal 197 amino acids of anillin, which includes a pleckstrin homology (PH) domain, form ectopic cortical foci during interphase. The septin Hcdc10 localizes to these ectopic foci, whereas myosin II and actin do not, suggesting that anillin interacts with the septins at the cortex. Robust cleavage furrow localization requires both this COOH-terminal domain and additional NH(2)-terminal sequences corresponding to an actin binding domain defined by in vitro cosedimentation assays. Endogenous anillin and Hcdc10 colocalize to punctate foci associated with actin cables throughout mitosis and the accumulation of both proteins at the cell equator requires filamentous actin. These results indicate that anillin is a conserved cleavage furrow component important for cytokinesis. Interactions with at least two other furrow proteins, actin and the septins, likely contribute to anillin function.
Cell Biology Program, European Molecular Biology Laboratory, Heidelberg, Germany D-69117, USA. karen.oegema@embl-heidelerg.de
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Oegema
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Savoian
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Mitchison
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Field
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D001798:Blood Proteins; D002451:Cell Compartmentation; D018797:Cell Cycle Proteins / Q000302:isolation & purification; D002455:Cell Division; D017124:Conserved Sequence; D003285:Contractile Proteins / Q000235:genetics* / Q000302:isolation & purification; D004330:Drosophila / Q000235:genetics*; D019143:Evolution, Molecular; D006801:Humans; D008840:Microfilament Proteins / Q000235:genetics* / Q000302:isolation & purification; D008969:Molecular Sequence Data; D010750:Phosphoproteins; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000302:isolation & purification; D058112:Septins; D017386:Sequence Homology, Amino Acid
D001798:Blood Proteins; D018797:Cell Cycle Proteins; D003285:Contractile Proteins; D008840:Microfilament Proteins; D010750:Phosphoproteins; D011993:Recombinant Fusion Proteins; C095886:anillin; C039077:platelet protein P47; C113158:SEPTIN7 protein, human; D058112:Septins