help button home button Genetics J Neurophys
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Originally published as Genetics Published Articles Ahead of Print on February 4, 2007.

Genetics, Vol. 175, 1571-1584, April 2007, Copyright © 2007
doi:10.1534/genetics.106.061309

This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Data Supplement
Right arrow All Versions of this Article:
genetics.106.061309v1
175/4/1571    most recent
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Related articles in Genetics
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Tange, Y.
Right arrow Articles by Niwa, O.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Tange, Y.
Right arrow Articles by Niwa, O.

Novel mad2 Alleles Isolated in a Schizosaccharomyces pombe {gamma}-Tubulin Mutant Are Defective in Metaphase Arrest Activity, but Remain Functional for Chromosome Stability in Unperturbed Mitosis

Yoshie Tange and Osami Niwa1

Kazusa DNA Research Institute, Kisarazu, Chiba 292-0818, Japan

1 Corresponding author: Kazusa DNA Research Institute, 2-6-7 Kazusa-kamatari, Kisarazu, Chiba 292-0818, Japan.
E-mail: niwa{at}kazusa.or.jp

A previously isolated fission yeast {gamma}-tubulin mutant containing apparently stabilized microtubules proliferated at an approximately identical rate as wild type, yet the mutant mitosis spindle dynamics were aberrant, particularly the kinetochore microtubule dynamics. Progression through mitosis in the mutant, however, resulted in mostly accurate chromosome segregation. In the absence of the spindle assembly checkpoint gene, mad2+, the spindle dynamics in the {gamma}-tubulin mutant were greatly compromised, leading to a high incidence of chromosome missegregation. Unlike in wild-type cells, green fluorescent protein (GFP)-tagged Mad2 protein often accumulated near one of the poles of an elongating spindle in the {gamma}-tubulin mutant. We isolated novel mad2 mutants that were defective in arresting mitotic progression upon gross perturbation of the spindle formation but remained functional for the viability of the {gamma}-tubulin mutant. Further, the mad2 mutations did not appreciably destabilize minichromosomes in unperturbed mitoses. When overexpressed ectopically, these mutant Mad2 proteins sequestered wild-type Mad2, preventing its function in mitotic checkpoint arrest, but not in minichromosome stability. These results indicated that the Mad2 functions required for checkpoint arrest and chromosome stability in unperturbed mitosis are genetically discernible. Immunoprecipitation studies demonstrated that GFP-fused mutant Mad2 proteins formed a Mad1-containing complex with altered stability compared to that formed with wild-type Mad2, providing clues to the novel mad2 mutant phenotype.


Related articles in Genetics:

ISSUE HIGHLIGHTS

Genetics 2007 175: NP. [Full Text]  



This article has been cited by other articles:


Home page
 GeneticsHome page
Y. Tange and O. Niwa
Schizosaccharomyces pombe Bub3 Is Dispensable for Mitotic Arrest Following Perturbed Spindle Formation
Genetics, June 1, 2008; 179(2): 785 - 792.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2007 by the Genetics Society of America.