Pericentrin and gamma-tubulin form a protein complex and are organized into a novel lattice at the centrosome
Autor: | Fredric S. Fay, Cynthia A. Sparks, Walter A. Carrington, Yixian Zheng, Charles A. Vidair, Aaron Isadore Young, Stephen J. Doxsey, Wendy Zimmerman, Jason B. Dictenberg |
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Rok vydání: | 1998 |
Předmět: |
Centriole
Xenopus Fluorescent Antibody Technique Centrosome cycle CHO Cells Biology Cell Fractionation 7. Clean energy Microtubules Centriole elongation 03 medical and health sciences 0302 clinical medicine Microtubule Tubulin Cricetinae Centrifugation Density Gradient Animals Antigens Cells Cultured 030304 developmental biology Microtubule nucleation Pericentriolar material Centrosome 0303 health sciences Cell Cycle Cell Biology Cell biology COS Cells Chromatography Gel CEP135 Microtubule-Associated Proteins 030217 neurology & neurosurgery Regular Articles |
Zdroj: | The Journal of Cell Biology |
ISSN: | 0021-9525 |
Popis: | Pericentrin and gamma-tubulin are integral centrosome proteins that play a role in microtubule nucleation and organization. In this study, we examined the relationship between these proteins in the cytoplasm and at the centrosome. In extracts prepared from Xenopus eggs, the proteins were part of a large complex as demonstrated by sucrose gradient sedimentation, gel filtration and coimmunoprecipitation analysis. The pericentrin-gamma-tubulin complex was distinct from the previously described gamma-tubulin ring complex (gamma-TuRC) as purified gamma-TuRC fractions did not contain detectable pericentrin. When assembled at the centrosome, the two proteins remained in close proximity as shown by fluorescence resonance energy transfer. The three- dimensional organization of the centrosome-associated fraction of these proteins was determined using an improved immunofluorescence method. This analysis revealed a novel reticular lattice that was conserved from mammals to amphibians, and was organized independent of centrioles. The lattice changed dramatically during the cell cycle, enlarging from G1 until mitosis, then rapidly disassembling as cells exited mitosis. In cells colabeled to detect centrosomes and nucleated microtubules, lattice elements appeared to contact the minus ends of nucleated microtubules. Our results indicate that pericentrin and gamma-tubulin assemble into a unique centrosome lattice that represents the higher-order organization of microtubule nucleating sites at the centrosome. |
Databáze: | OpenAIRE |
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