Mutations in α-tubulin promote basal body maturation and flagellar assembly in the absence of δ-tubulin
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- Sylvia Fromherz
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, Boulder, CO 80309-0347, USA
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- Thomas H. Giddings
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, Boulder, CO 80309-0347, USA
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- Natalia Gomez-Ospina
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, Boulder, CO 80309-0347, USA
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- Susan K. Dutcher
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, Boulder, CO 80309-0347, USA
説明
<jats:p>We have isolated suppressors of the deletion allele of δ-tubulin, uni3-1, in the biflagellate green alga Chlamydomonas reinhardtii. The deletion of δ-tubulin produces cells that assemble zero, one or two flagella and have basal bodies composed primarily of doublet rather than triplet microtubules. Flagellar number is completely restored in the suppressed strains. Most of the uni3-1 suppressors map to the TUA2 locus, which encodes α2-tubulin. Twelve independent tua2 mutations were sequenced. Amino acids D205 or A208, which are nearly invariant residues in α-tubulin, were altered. The tua2 mutations on their own have a second phenotype - they make the cells colchicine supersensitive. Colchicine supersensitivity itself is not needed for suppression and colchicine cannot phenocopy the suppression. The suppressors partially restore the assembly of triplet microtubules. These results suggest that the δ-tubulin plays two roles: it is needed for extension or stability of the triplet microtubule and also for early maturation of basal bodies. We suggest that the mutant α-tubulin promotes the early maturation of the basal body in the absence of δ-tubulin, perhaps through interactions with other partners, and this allows assembly of the flagella.</jats:p>
収録刊行物
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- Journal of Cell Science
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Journal of Cell Science 117 (2), 303-314, 2004-01-15
The Company of Biologists