GTP regulates the microtubule nucleation activity of γ-tubulin

• Verfasst von: Gombos, Linda [VerfasserIn]
• Verfasst von: Neuner, Annett [VerfasserIn]
• Verfasst von: Berinski, Michael [VerfasserIn]
• Verfasst von: Fava, Luca L. [VerfasserIn]
• Verfasst von: Wade, Rebecca C. [VerfasserIn]
• Verfasst von: Sachse, Carsten [VerfasserIn]
• Verfasst von: Schiebel, Elmar [VerfasserIn]
• Titel: GTP regulates the microtubule nucleation activity of γ-tubulin
• Verf.angabe: Linda Gombos, Annett Neuner, Mykhaylo Berynskyy, Luca L. Fava, Rebecca C. Wade, Carsten Sachse and Elmar Schiebel
• E-Jahr: 2013
• Jahr: 27 October 2013
• Umfang: 11 S.
• Fussnoten: Gesehen am 17.02.2020
• Titel Quelle: Enthalten in: Nature cell biology
• Ort Quelle: New York, NY : Nature America, 1999
• Jahr Quelle: 2013
• Band/Heft Quelle: 15(2013), 11, Seite 1317-1327
• ISSN Quelle: 1476-4679
• DOI: doi:10.1038/ncb2863
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1748531921

Abstract

Both subunits of αβ-tubulin that comprise the core components of microtubules bind GTP. GTP binding to α-tubulin has a structural role, whereas β-tubulin binds and hydrolyses GTP to regulate microtubule dynamics. γ-tubulin, another member of the tubulin superfamily that seeds microtubule nucleation at microtubule-organizing centres, also binds GTP; however, the importance of this association remains elusive. To address the role of GTP binding to γ-tubulin, we systematically mutagenized the GTP contact residues in the yeast γ-tubulin Tub4. Tub4GTP-mutant proteins that exhibited greatly reduced GTP affinity still assembled into the small γ-tubulin complex. However, tub4GTP mutants were no longer viable, and had defects in interaction between γ-tubulin and αβ-tubulin, decreased microtubule nucleation and defects in microtubule organization. In vitro and in vivo data show that only γ-tubulin loaded with GTP nucleates microtubules. Our results suggest that GTP recruitment to γ-tubulin enhances its interaction with αβ-tubulin similarly to GTP recruitment to β-tubulin.