|
|
|
|
|
|
|
|
|||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | |||||
First published online September 12, 2003
doi: 10.1242/10.1242/jcs.00706
Research Article |
1 Laboratoire d'Ingenierie des Systemes Macromoleculaires CNRS UPR9027, 31 chemin Joseph Aiguier, 13402 Marseille Cedex 20, France
2 Service de Microscopie Electronique, IBSM, Marseille, France
* Author for correspondence (e-mail: mnsimon{at}ibsm.cnrs-mrs.fr)
Accepted 11 June 2003
The mitotic cyclin Clb2 plays a major role in promoting M-phase in budding yeast, despite its functional redundancy with three closely related cyclins Clb1, Clb3 and Clb4. Here, we further investigate the mechanisms controlling the cellular distribution of Clb2 in living cells. In agreement with observations recently made by Hood et al. [Hood, J. K., Hwang, W. W. and Silver, P. A. (2001) J. Cell Sci. 114, 589-597], we find that GFP-tagged Clb2 expressed from its natural promoter localizes to various cellular compartments, including the nucleus, the mitotic spindle, the spindle pole bodies as well as the mother-bud neck. The neck localization is specific to Clb2 as Clb1, Clb3 and Clb4 are never observed there, even when over-expressed. Mutational analysis identifies a central region of Clb2, comprising residues 213-255 and a phylogenetically conserved hydrophobic patch, as an essential cis-acting determinant. Clb2 co-localizes with the bud site selection protein Bud3. Consistent with a role of Bud3 in targeting Clb2 to the bud neck, we report a two-hybrid interaction between these proteins. Furthermore, Clb2 is shown to be specifically delocalized in 
bud3 cells and in a bud3 mutant deleted for its C-terminal Clb2-interacting domain (bud31221), but not in a bud10 mutant. Correlating with this phenotype, bud31221 cells exhibit a pronounced (15-30 minutes) delay in cytokinesis and/or cell separation, suggesting an unanticipated function of Clb2 in these late mitotic events. Taken together, our data uncover a new role for Bud3 in cytokinesis that correlates with its capacity to target Clb2 at the neck, independently of its well established cell-type-specific function in bud site selection.
Key words: Budding yeast, Cyclins, Cell cycle, Bud3, Cytokinesis
Related articles in JCS:
This article has been cited by other articles:
|
|
 |
|
  A. M. Bentley, G. Normand, J. Hoyt, and R. W. King Distinct Sequence Elements of Cyclin B1 Promote Localization to Chromatin, Centrosomes, and Kinetochores during Mitosis Mol. Biol. Cell, December 1, 2007; 18(12): 4847 - 4858. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. Eluere, N. Offner, I. Varlet, O. Motteux, L. Signon, A. Picard, E. Bailly, and M.-N. Simon Compartmentalization of the functions and regulation of the mitotic cyclin Clb2 in S. cerevisiae J. Cell Sci., February 15, 2007; 120(4): 702 - 711. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. S. Martinez, D.-E. Jeong, E. Choi, B. M. Billings, and M. C. Hall Acm1 Is a Negative Regulator of the Cdh1-Dependent Anaphase-Promoting Complex/Cyclosome in Budding Yeast Mol. Cell. Biol., December 15, 2006; 26(24): 9162 - 9176. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. Zhang, R. Kashimshetty, K. E. Ng, H. B. Tan, and F. M. Yeong Exit from mitosis triggers Chs2p transport from the endoplasmic reticulum to mother-daughter neck via the secretory pathway in budding yeast J. Cell Biol., July 17, 2006; 174(2): 207 - 220. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. Maekawa and E. Schiebel Cdk1-Clb4 controls the interaction of astral microtubule plus ends with subdomains of the daughter cell cortex Genes & Dev., July 15, 2004; 18(14): 1709 - 1724. [Abstract] [Full Text] [PDF]
|
|
