Display Settings:

Format

Send to:

Choose Destination
See comment in PubMed Commons below
Mol Biol Cell. 2012 Jul;23(13):2445-56. doi: 10.1091/mbc.E12-01-0033. Epub 2012 May 9.

Mitotic exit kinase Dbf2 directly phosphorylates chitin synthase Chs2 to regulate cytokinesis in budding yeast.

Author information

  • 1Department of Cell and Developmental Biology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA.

Abstract

How cell cycle machinery regulates extracellular matrix (ECM) remodeling during cytokinesis remains poorly understood. In the budding yeast Saccharomyces cerevisiae, the primary septum (PS), a functional equivalent of animal ECM, is synthesized during cytokinesis by the chitin synthase Chs2. Here, we report that Dbf2, a conserved mitotic exit kinase, localizes to the division site after Chs2 and directly phosphorylates Chs2 on several residues, including Ser-217. Both phosphodeficient (chs2-S217A) and phosphomimic (chs2-S217D) mutations cause defects in cytokinesis, suggesting that dynamic phosphorylation-dephosphorylation of Ser-217 is critical for Chs2 function. It is striking that Chs2-S217A constricts asymmetrically with the actomyosin ring (AMR), whereas Chs2-S217D displays little or no constriction and remains highly mobile at the division site. These data suggest that Chs2 phosphorylation by Dbf2 triggers its dissociation from the AMR during the late stage of cytokinesis. Of interest, both chs2-S217A and chs2-S217D mutants are robustly suppressed by increased dosage of Cyk3, a cytokinesis protein that displays Dbf2-dependent localization and also stimulates Chs2-mediated chitin synthesis. Thus Dbf2 regulates PS formation through at least two independent pathways: direct phosphorylation and Cyk3-mediated activation of Chs2. Our study establishes a mechanism for direct cell cycle control of ECM remodeling during cytokinesis.

PMID:
22573892
[PubMed - indexed for MEDLINE]
PMCID:
PMC3386209
Free PMC Article

Images from this publication.See all images (8)Free text

FIGURE 1:
FIGURE 2:
FIGURE 3:
FIGURE 4:
FIGURE 5:
FIGURE 6:
FIGURE 7:
FIGURE 8:
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Write to the Help Desk