The conserved protein SZY-20 opposes the Plk4-related kinase ZYG-1 to limit centrosome size.
Microtubules are organized by the centrosome, a dynamic organelle that exhibits changes in both size and number during the cell cycle. Here we show that SZY-20, a putative RNA-binding protein, plays a critical role in limiting centrosome size in C. elegans. SZY-20 localizes in part to centrosomes and in its absence centrosomes possess increased levels of centriolar and pericentriolar components including gamma-tubulin and the centriole duplication factors ZYG-1 and SPD-2. These enlarged centrosomes possess normal centrioles, nucleate more microtubules, and fail to properly direct a number of microtubule-dependent processes. Depletion of ZYG-1 restores normal centrosome size and function to szy-20 mutants, whereas loss of szy-20 suppresses the centrosome duplication defects in both zyg-1 and spd-2 mutants. Our results describe a pathway that determines centrosome size and implicate centriole duplication factors in this process.
Song
Mi Hye
MH
Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20894, USA. mihyesong@mail.nih.gov
Aravind
L
L
Müller-Reichert
Thomas
T
O'Connell
Kevin F
KF
D000483:Alleles; D000818:Animals; D017173:Caenorhabditis elegans; D029742:Caenorhabditis elegans Proteins / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*; D002467:Cell Nucleus / Q000378:metabolism; D002502:Centrioles / Q000648:ultrastructure; D018385:Centrosome / Q000648:ultrastructure*; D018507:Gene Expression Regulation, Developmental; D008870:Microtubules / Q000378:metabolism; D008954:Models, Biological; D008957:Models, Genetic; D009154:Mutation; D011494:Protein Kinases / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000378:metabolism / Q000502:physiology*
D029742:Caenorhabditis elegans Proteins; D016601:RNA-Binding Proteins; C534298:SZY-20 protein, C elegans; D011494:Protein Kinases; C429649:zyg-1 protein, C elegans; D017346:Protein Serine-Threonine Kinases