Daughter centriole elongation is controlled by proteolysis.
The centrosome is the major microtubule-organizing center of most mammalian cells and consists of a pair of centrioles embedded in pericentriolar material. Before mitosis, the two centrioles duplicate and two new daughter centrioles form adjacent to each preexisting maternal centriole. After initiation of daughter centriole synthesis, the procentrioles elongate in a process that is poorly understood. Here, we show that inhibition of cellular proteolysis by Z-L3VS or MG132 induces abnormal elongation of daughter centrioles to approximately 4 times their normal length. This activity of Z-L3VS or MG132 was found to correlate with inhibition of intracellular protease-mediated substrate cleavage. Using a small interfering RNA screen, we identified a total of nine gene products that either attenuated (seven) or promoted (two) abnormal Z-L3VS-induced daughter centriole elongation. Our hits included known regulators of centriole length, including CPAP and CP110, but, interestingly, several proteins involved in microtubule stability and anchoring as well as centrosome cohesion. This suggests that nonproteasomal functions, specifically inhibition of cellular proteases, may play an important and underappreciated role in the regulation of centriole elongation. They also highlight the complexity of daughter centriole length control and provide a framework for future studies to dissect the molecular details of this process.
Korzeniewski
Nina
N
Cancer Virology Program, University of Pittsburgh Cancer Institute, Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA.
Cuevas
Rolando
R
Duensing
Anette
A
Duensing
Stefan
S
D002135:Calcium-Binding Proteins / Q000235:genetics / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D045744:Cell Line, Tumor; D002502:Centrioles / Q000378:metabolism* / Q000648:ultrastructure; D018385:Centrosome / Q000378:metabolism*; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics / Q000378:metabolism; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D015151:Immunoblotting; D007976:Leupeptins / Q000494:pharmacology; D046529:Microscopy, Electron, Transmission; D008856:Microscopy, Fluorescence; D008868:Microtubule Proteins / Q000235:genetics / Q000378:metabolism; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism; D008870:Microtubules / Q000378:metabolism / Q000648:ultrastructure; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D009842:Oligopeptides / Q000494:pharmacology; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism*; D061988:Proteasome Inhibitors; D034622:RNA Interference; D013450:Sulfones / Q000494:pharmacology; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
C467559:CCP110 protein, human; C414735:CENPJ protein, human; C509238:CEP350 protein, human; C523555:CEP97 protein, human; C541075:CHTOP protein, human; D002135:Calcium-Binding Proteins; D018797:Cell Cycle Proteins; D002868:Chromosomal Proteins, Non-Histone; D015853:Cysteine Proteinase Inhibitors; D007976:Leupeptins; D008868:Microtubule Proteins; D008869:Microtubule-Associated Proteins; D009687:Nuclear Proteins; D009842:Oligopeptides; D010750:Phosphoproteins; D061988:Proteasome Inhibitors; D013450:Sulfones; D014157:Transcription Factors; C106727:carboxybenzyl-leucyl-leucyl-leucine vinyl sulfone; C056608:caltractin; D049452:Green Fluorescent Proteins; D046988:Proteasome Endopeptidase Complex; C072553:benzyloxycarbonylleucyl-leucyl-leucine aldehyde