Proper recruitment of gamma-tubulin and D-TACC/Msps to embryonic Drosophila centrosomes requires Centrosomin Motif 1.
Centrosomes are microtubule-organizing centers and play a dominant role in assembly of the microtubule spindle apparatus at mitosis. Although the individual binding steps in centrosome maturation are largely unknown, Centrosomin (Cnn) is an essential mitotic centrosome component required for assembly of all other known pericentriolar matrix (PCM) proteins to achieve microtubule-organizing activity at mitosis in Drosophila. We have identified a conserved motif (Motif 1) near the amino terminus of Cnn that is essential for its function in vivo. Cnn Motif 1 is necessary for proper recruitment of gamma-tubulin, D-TACC (the homolog of vertebrate transforming acidic coiled-coil proteins [TACC]), and Minispindles (Msps) to embryonic centrosomes but is not required for assembly of other centrosome components including Aurora A kinase and CP60. Centrosome separation and centrosomal satellite formation are severely disrupted in Cnn Motif 1 mutant embryos. However, actin organization into pseudocleavage furrows, though aberrant, remains partially intact. These data show that Motif 1 is necessary for some but not all of the activities conferred on centrosome function by intact Cnn.
Department of Pharmacology, The Cecil and Ida Green Center for Reproductive Biology Sciences, The University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390-9051, USA.
Jiuli
J
Zhang
Timothy L
TL
Megraw
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D018385:Centrosome / Q000378:metabolism*; D022083:Cytoplasmic Structures / Q000378:metabolism; D029721:Drosophila Proteins / Q000737:chemistry / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000166:cytology / Q000196:embryology* / Q000378:metabolism; D004625:Embryo, Nonmammalian / Q000166:cytology / Q000378:metabolism*; D005799:Genes, Dominant; D018398:Homeodomain Proteins / Q000737:chemistry / Q000378:metabolism*; D008869:Microtubule-Associated Proteins / Q000378:metabolism*; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D021381:Protein Transport; D013329:Structure-Activity Relationship; D014404:Tubulin / Q000378:metabolism*
D029721:Drosophila Proteins; D018398:Homeodomain Proteins; D008869:Microtubule-Associated Proteins; C404402:TACC protein, Drosophila; D014404:Tubulin; C098130:cnn protein, Drosophila; C121511:msps protein, Drosophila