The negatively charged carboxy-terminal tail of β-tubulin promotes proper chromosome segregation
| Autor: | Thomas H. Giddings, Colby P. Fees, Jeffrey K. Moore, Eileen T. O'Toole, Jayne Aiken |
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| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
Cell division Mutant macromolecular substances Spindle Apparatus Biology Microtubules Spindle pole body Chromosome segregation 03 medical and health sciences Protein Domains Microtubule Tubulin Chromosome Segregation Kinetochores Molecular Biology Cytoskeleton Kinetochore Cell Biology Articles Cell biology Spindle apparatus 030104 developmental biology Saccharomycetales biology.protein Cell Division |
| Zdroj: | Molecular Biology of the Cell |
| ISSN: | 1939-4586 1059-1524 |
| Popis: | Microtubules are essential for chromosome segregation. A study of the mechanistic contributions of tubulin proteins identifies a specific role for the negatively charged carboxy-terminal tail domain of b-tubulin in positioning kinetochores in the mitotic spindle and ensuring efficient and accurate chromosome segregation. Despite the broadly conserved role of microtubules in chromosome segregation, we have a limited understanding of how molecular features of tubulin proteins contribute to the underlying mechanisms. Here we investigate the negatively charged carboxy-terminal tail domains (CTTs) of α- and β-tubulins, using a series of mutants that alter or ablate CTTs in budding yeast. We find that ablating β-CTT causes elevated rates of chromosome loss and cell cycle delay. Complementary live-cell imaging and electron tomography show that β-CTT is necessary to properly position kinetochores and organize microtubules within the assembling spindle. We identify a minimal region of negatively charged amino acids that is necessary and sufficient for proper chromosome segregation and provide evidence that this function may be conserved across species. Our results provide the first in vivo evidence of a specific role for tubulin CTTs in chromosome segregation. We propose that β-CTT promotes the ordered segregation of chromosomes by stabilizing the spindle and contributing to forces that move chromosomes toward the spindle poles. |
| Databáze: | OpenAIRE |
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