HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Supplemental Data All Versions of this Article: fj.07-081463v1 22/6/1960    most recent Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Yang, S. Articles by Zhou, J. PubMed PubMed Citation Articles by Yang, S. Articles by Zhou, J.

Tastin is required for bipolar spindle assembly and centrosome integrity during mitosis

Shuo Yang^*, Xuan Liu^*, Yanqing Yin^*, Michiko N. Fukuda and Jiawei Zhou^*,1

^* Laboratory of Molecular Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China; and

Cancer Research Center, Burnham Institute, La Jolla, California, USA

¹Correspondence: Institute of Neuroscience, Chinese Academy of Sciences, 320 Yueyang Rd., Shanghai, 200031, China. E-mail: jwzhou{at}ion.ac.cn

Tastin was previously characterized as an accessory protein for cell adhesion that participates in early embryo implantation. Here, we report that tastin is also required for spindle assembly during mitosis. Tastin protein levels peaked in the G₂/M phase and abruptly declined after cell division. Microscopy showed that tastin is primarily localized on the microtubules, centrosomes, and the mitotic spindle during the cell cycle. Tastin interacted with the dynein intermediate chain, p150^Glued, and -tubulin in addition to Tctex-1 (the light chain of dynein). Overexpression of tastin led to monopolar spindle formation, whereas loss of tastin expression caused profound mitotic block and preferentially induced multipolar spindles. These multipolar spindles were generated through a loss of cohesion in mitotic centrosomes; specifically, tastin depletion caused the fragmentation of pericentrosomal material and the splitting of the centrioles at the spindle poles. Tastin depletion induced centrosome abnormalities exclusively during mitosis and required both microtubule integrity and Eg5 activity. However, tastin depletion did not disrupt the organization of spindle poles, as revealed by localization of nuclear mitotic apparatus protein (NuMA) and the p150^Glued component of dynactin. These data indicate that the major function of tastin during mitosis is to maintain the structural and dynamic features of centrosomes, thereby contributing to spindle bipolarity.—Yang, S., Liu, X., Yin, Y., Fukuda, M. N., Zhou, J. Tastin is required for bipolar spindle assembly and centrosome integrity during mitosis.

Key Words: microtubules • mitotic block