spacer gif spacer gif spacer gif spacer gif Boveri Book spacer gif
QUICK SEARCH:   [advanced]


spacer gif
     Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents    

First published online 5 February 2008
doi: 10.1242/jcs.022772

Journal of Cell Science 121, 601-608 (2008)
Published by The Company of Biologists 2008
This Article
Right arrow Figures Only
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Supplementary Material
Right arrow All Versions of this Article:
jcs.022772v1
121/5/601    most recent
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Related articles in JCS
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
Google Scholar
Right arrow Articles by Krapp, A.
Right arrow Articles by Simanis, V.
PubMed
Right arrow PubMed Citation
Right arrow Articles by Krapp, A.
Right arrow Articles by Simanis, V.

Research Article

Homoeostasis between the GTPase Spg1p and its GAP in the regulation of cytokinesis in S. pombe

Andrea Krapp, Philippe Collin, Elena Cano del Rosario and Viesturs Simanis*

Cell Cycle Control Laboratory, Swiss Institute for Experimental Cancer Research (ISREC), Life Sciences Faculty, EPFL, 1066 Epalinges, Switzerland

* Author for correspondence (e-mail: viesturs.simanis{at}isrec.ch)

Accepted 19 November 2007

Cytokinesis in Schizosaccharomyces pombe begins at mitotic entry, when the site of division is defined by formation of the contractile acto-myosin ring (CAR) at the cell cortex. Contraction of the CAR and formation of the division septum are triggered at the end of mitosis by septation initiation network (SIN) proteins associated with the spindle pole body (SPB). SIN signalling requires activation of the GTPase Spg1p, which is regulated by the bipartite GTPase-activating protein (GAP) Byr4p-Cdc16p. We show that, for Spg1p to associate with the SPB, it must be bound to its GAP or to its mitotic effector, the protein kinase Cdc7p. Analysis of the GAP proteins reveals that the steady-state level of Byr4p reflects that of Spg1p. Furthermore, if the interaction of Byr4p with Spg1p is compromised, the level of Byr4p decreases dramatically. The adaptation of the level of Byr4p to that of Spg1p requires the presence of Cdc16p and is mediated by proteasome-dependent destruction. It requires neither association with the SPB nor an active SIN. We propose a mechanism that limits the amount of the Byr4p-Cdc16p GAP to the amount required to inhibit Spg1p signalling.

Key words: Cytokinesis, S. pombe, GTPase activating protein (GAP), Proteolysis


Related articles in JCS:

Cytokinesis: Spg1p and Byr4p partner up

JCS 2008 121: 505. [Full Text]  





© The Company of Biologists Ltd 2008