Centrocortin cooperates with centrosomin to organize Drosophila embryonic cleavage furrows.
In the Drosophila early embryo, the centrosome coordinates assembly of cleavage furrows. Currently, the molecular pathway that links the centrosome and the cortical microfilaments is unknown. In centrosomin (cnn) mutants, in which the centriole forms but the centrosome pericentriolar material (PCM) fails to assemble, actin microfilaments are not organized into furrows at the syncytial cortex [6]. Although CNN is required for centrosome assembly and function, little is known of its molecular activities. Here, we show the novel protein Centrocortin (CEN), which associates with centrosomes and also with cleavage furrows in early embryos, is required for cleavage furrow assembly. CEN binds to CNN within CNN Motif 2 (CM2), a conserved 60 amino acid domain at CNN's C terminus. The cnn(B4) allele, which contains a missense mutation at a highly conserved residue within CM2, blocks the binding of CEN and disrupts cleavage furrow assembly. Together, these findings show that the C terminus of CNN coordinates cleavage furrow formation through binding to CEN, thereby providing a molecular link between the centrosome and cleavage furrow assembly.
Department of Pharmacology and The Cecil and Ida Green Center for Reproductive Biology Sciences, The University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390-9051, USA.
Ling-Rong
LR
Kao
Timothy L
TL
Megraw
D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D018385:Centrosome / Q000378:metabolism / Q000648:ultrastructure; D017124:Conserved Sequence; D004330:Drosophila / Q000196:embryology* / Q000648:ultrastructure; D029721:Drosophila Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D004625:Embryo, Nonmammalian / Q000502:physiology* / Q000648:ultrastructure; D047108:Embryonic Development / Q000502:physiology*; D018398:Homeodomain Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D009154:Mutation; D017434:Protein Structure, Tertiary; D015398:Signal Transduction / Q000235:genetics
C544116:CEN protein, Drosophila; D029721:Drosophila Proteins; D018398:Homeodomain Proteins; C098130:cnn protein, Drosophila