JCB logo
MBL International Tel: 800.200.5459 CLICK HERE
  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents
This Article
Right arrow Full Text
Right arrow Full Text (PDF, 711K)
Right arrow PPT slides of all figures
Right arrow Supplemental Material Index
Right arrow Alert me when this article is cited
Right arrow Citation Map
Services
Right arrow Email this article
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new content in the JCB
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via CrossRef
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Wittmann, T.
Right arrow Articles by Vernos, I.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Wittmann, T.
Right arrow Articles by Vernos, I.
Right arrowPubmed/NCBI databases
*Domain*Gene
*GEO Profiles*HomoloGene
*Protein*UniGene
*Substance via MeSH
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Facebook   Add to Reddit   Add to Technorati   Add to Twitter  
What's this?

© The Rockefeller University Press, 0021-9525/2000//1405 $5.00
The Journal of Cell Biology, Volume 149, Number 7, , 2000 1405-1418

Original Article

Tpx2, a Novel Xenopus Map Involved in Spindle Pole Organization



Torsten Wittmanna, Matthias Wilmb, Eric Karsentia, and Isabelle Vernosa

a Cell Biology and Cell Biophysics Program, European Molecular Biology Laboratory, D-69117 Heidelberg, Germany
b Biochemical Instrumentation Program, European Molecular Biology Laboratory, D-69117 Heidelberg, Germany
European Molecular Biology Laboratory, Cell Biology and Cell Biophysics Program, D-69117 Heidelberg, Germany.49 6221 387 51249 6221 387 342

vernos{at}embl-heidelberg.de

TPX2, the targeting protein for Xenopus kinesin-like protein 2 (Xklp2), was identified as a microtubule-associated protein that mediates the binding of the COOH-terminal domain of Xklp2 to microtubules (Wittmann, T., H. Boleti, C. Antony, E. Karsenti, and I. Vernos. 1998. J. Cell Biol. 143:673–685). Here, we report the cloning and functional characterization of Xenopus TPX2. TPX2 is a novel, basic 82.4-kD protein that is phosphorylated during mitosis in a microtubule-dependent way. TPX2 is nuclear during interphase and becomes localized to spindle poles in mitosis. Spindle pole localization of TPX2 requires the activity of the dynein–dynactin complex. In late anaphase TPX2 becomes relocalized from the spindle poles to the midbody. TPX2 is highly homologous to a human protein of unknown function and thus defines a new family of vertebrate spindle pole components. We investigated the function of TPX2 using spindle assembly in Xenopus egg extracts. Immunodepletion of TPX2 from mitotic egg extracts resulted in bipolar structures with disintegrating poles and a decreased microtubule density. Addition of an excess of TPX2 to spindle assembly reactions gave rise to monopolar structures with abnormally enlarged poles. We conclude that, in addition to its function in targeting Xklp2 to microtubule minus ends during mitosis, TPX2 also participates in the organization of spindle poles.

Key Words: spindle pole • microtubules • dynein– • dynactin • TPX2 • Xklp2

© 2000 The Rockefeller University Press

The online version of this article contains supplemental material.

Abbreviations used in this paper: cdc2 kinase, cyclin-dependent kinase 2; CSF, cytostatic factor; GFP, green fluorescent protein; GST, glutathione-S-transferase; KLP(s), kinesin-like protein(s); MAP(s), microtubule-associated protein(s); MAP kinase, mitogen-activated protein kinase; TPX2, targeting protein for Xklp2; Xklp2, Xenopus kinesin-like protein 2.


Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Facebook Facebook   Add to Reddit Reddit   Add to Technorati Technorati   Add to Twitter Twitter    What's this?


This article has been cited by other articles:



  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents