Centriolar SAS-5 is required for centrosome duplication in C. elegans.
Centrosomes, the major microtubule-organizing centres (MTOCs) of animal cells, are comprised of a pair of centrioles surrounded by pericentriolar material (PCM). Early in the cell cycle, there is a single centrosome, which duplicates during S-phase to direct bipolar spindle assembly during mitosis. Although crucial for proper cell division, the mechanisms that govern centrosome duplication are not fully understood. Here, we identify the Caenorhabditis elegans gene sas-5 as essential for daughter-centriole formation. SAS-5 is a coiled-coil protein that localizes primarily to centrioles. Fluorescence recovery after photobleaching (FRAP) experiments with green fluorescent protein (GFP) fused to SAS-5 (GFP-SAS-5) demonstrated that the protein shuttles between centrioles and the cytoplasm throughout the cell cycle. Analysis of mutant alleles revealed that the presence of SAS-5 at centrioles is crucial for daughter-centriole formation and that ZYG-1, a kinase that is also essential for this process, controls the distribution of SAS-5 to centrioles. Furthermore, partial RNA-interference (RNAi)-mediated inactivation experiments suggest that both sas-5 and zyg-1 are dose-dependent regulators of centrosome duplication.
Delattre
Marie
M
Swiss Institute for Experimental Cancer Research (ISREC), CH-1066 Epalinges/Lausanne, Switzerland.
Leidel
Sebastian
S
Wani
Khursheed
K
Baumer
Karine
K
Bamat
Jeannine
J
Schnabel
Heinke
H
Feichtinger
Richard
R
Schnabel
Ralf
R
Gönczy
Pierre
P
D021581:Active Transport, Cell Nucleus / Q000235:genetics; D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D002502:Centrioles / Q000378:metabolism* / Q000648:ultrastructure; D018385:Centrosome / Q000378:metabolism* / Q000648:ultrastructure; D018628:Gene Dosage; D008854:Microscopy, Electron; D008938:Mitosis / Q000235:genetics*; D008969:Molecular Sequence Data; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism; D021381:Protein Transport / Q000235:genetics; D034622:RNA Interference / Q000502:physiology
D029742:Caenorhabditis elegans Proteins; D018797:Cell Cycle Proteins; C488496:SAS-5 protein, C elegans; D011494:Protein Kinases; C429649:zyg-1 protein, C elegans