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Actin-mediated Delivery of Astral Microtubules Instructs Kar9p Asymmetric Loading to the Bud-Ward Spindle Pole

In Saccharomyces cerevisiae, Kar9p, one player in spindle alignment, guides the bud-ward spindle pole by linking astral microtubule plus ends to Myo2p-based transport along actin cables generated by the formins Bni1p and Bnr1p and the polarity determinant Bud6p. Initially, Kar9p labels both poles bu...

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Autores principales: Cepeda-García, Cristina, Delgehyr, Nathalie, Juanes Ortiz, M. Angeles, ten Hoopen, Rogier, Zhiteneva, Alisa, Segal, Marisa
Formato: Texto
Lenguaje:English
Publicado: The American Society for Cell Biology 2010
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2912354/
https://www.ncbi.nlm.nih.gov/pubmed/20534809
http://dx.doi.org/10.1091/mbc.E10-03-0197
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author Cepeda-García, Cristina
Delgehyr, Nathalie
Juanes Ortiz, M. Angeles
ten Hoopen, Rogier
Zhiteneva, Alisa
Segal, Marisa
author_facet Cepeda-García, Cristina
Delgehyr, Nathalie
Juanes Ortiz, M. Angeles
ten Hoopen, Rogier
Zhiteneva, Alisa
Segal, Marisa
author_sort Cepeda-García, Cristina
collection PubMed
description In Saccharomyces cerevisiae, Kar9p, one player in spindle alignment, guides the bud-ward spindle pole by linking astral microtubule plus ends to Myo2p-based transport along actin cables generated by the formins Bni1p and Bnr1p and the polarity determinant Bud6p. Initially, Kar9p labels both poles but progressively singles out the bud-ward pole. Here, we show that this polarization requires cell polarity determinants, actin cables, and microtubules. Indeed, in a bud6Δ bni1Δ mutant or upon direct depolymerization of actin cables Kar9p symmetry increased. Furthermore, symmetry was selectively induced by myo2 alleles, preventing Kar9p binding to the Myo2p cargo domain. Kar9p polarity was rebuilt after transient disruption of microtubules, dependent on cell polarity and actin cables. Symmetry breaking also occurred after transient depolymerization of actin cables, with Kar9p increasing at the spindle pole engaging in repeated cycles of Kar9p-mediated transport. Kar9p returning to the spindle pole on shrinking astral microtubules may contribute toward this bias. Thus, Myo2p transport along actin cables may support a feedback loop by which delivery of astral microtubule plus ends sustains Kar9p polarized recruitment to the bud-ward spindle pole. Our findings also explain the link between Kar9p polarity and the choice setting aside the old spindle pole for daughter-bound fate.
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spelling pubmed-29123542010-10-16 Actin-mediated Delivery of Astral Microtubules Instructs Kar9p Asymmetric Loading to the Bud-Ward Spindle Pole Cepeda-García, Cristina Delgehyr, Nathalie Juanes Ortiz, M. Angeles ten Hoopen, Rogier Zhiteneva, Alisa Segal, Marisa Mol Biol Cell Articles In Saccharomyces cerevisiae, Kar9p, one player in spindle alignment, guides the bud-ward spindle pole by linking astral microtubule plus ends to Myo2p-based transport along actin cables generated by the formins Bni1p and Bnr1p and the polarity determinant Bud6p. Initially, Kar9p labels both poles but progressively singles out the bud-ward pole. Here, we show that this polarization requires cell polarity determinants, actin cables, and microtubules. Indeed, in a bud6Δ bni1Δ mutant or upon direct depolymerization of actin cables Kar9p symmetry increased. Furthermore, symmetry was selectively induced by myo2 alleles, preventing Kar9p binding to the Myo2p cargo domain. Kar9p polarity was rebuilt after transient disruption of microtubules, dependent on cell polarity and actin cables. Symmetry breaking also occurred after transient depolymerization of actin cables, with Kar9p increasing at the spindle pole engaging in repeated cycles of Kar9p-mediated transport. Kar9p returning to the spindle pole on shrinking astral microtubules may contribute toward this bias. Thus, Myo2p transport along actin cables may support a feedback loop by which delivery of astral microtubule plus ends sustains Kar9p polarized recruitment to the bud-ward spindle pole. Our findings also explain the link between Kar9p polarity and the choice setting aside the old spindle pole for daughter-bound fate. The American Society for Cell Biology 2010-08-01 /pmc/articles/PMC2912354/ /pubmed/20534809 http://dx.doi.org/10.1091/mbc.E10-03-0197 Text en © 2010 by The American Society for Cell Biology
spellingShingle Articles
Cepeda-García, Cristina
Delgehyr, Nathalie
Juanes Ortiz, M. Angeles
ten Hoopen, Rogier
Zhiteneva, Alisa
Segal, Marisa
Actin-mediated Delivery of Astral Microtubules Instructs Kar9p Asymmetric Loading to the Bud-Ward Spindle Pole
title Actin-mediated Delivery of Astral Microtubules Instructs Kar9p Asymmetric Loading to the Bud-Ward Spindle Pole
title_full Actin-mediated Delivery of Astral Microtubules Instructs Kar9p Asymmetric Loading to the Bud-Ward Spindle Pole
title_fullStr Actin-mediated Delivery of Astral Microtubules Instructs Kar9p Asymmetric Loading to the Bud-Ward Spindle Pole
title_full_unstemmed Actin-mediated Delivery of Astral Microtubules Instructs Kar9p Asymmetric Loading to the Bud-Ward Spindle Pole
title_short Actin-mediated Delivery of Astral Microtubules Instructs Kar9p Asymmetric Loading to the Bud-Ward Spindle Pole
title_sort actin-mediated delivery of astral microtubules instructs kar9p asymmetric loading to the bud-ward spindle pole
topic Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2912354/
https://www.ncbi.nlm.nih.gov/pubmed/20534809
http://dx.doi.org/10.1091/mbc.E10-03-0197
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