Mechanisms of cytokinesis in budding yeast

Institute of Chemistry and Biochemistry, Laboratory of Membrane Biochemistry and Molecular Cell Biology, Freie Universität Berlin, Takustraβe 6, Berlin, Germany.
Cytoskeleton (Impact Factor: 3.12). 10/2012; 69(10):710-26. DOI: 10.1002/cm.21046
Source: PubMed


Cytokinesis is essential for cell proliferation in all domains of life. Because the core components and mechanisms of cytokinesis are conserved from fungi to humans, the budding yeast Saccharomyces cerevisiae has served as an attractive model for studying this fundamental process. Cytokinesis in budding yeast is driven by two interdependent cellular events: actomyosin ring (AMR) constriction and the formation of a chitinous cell wall structure called the primary septum (PS), the functional equivalent of extracellular matrix remodeling during animal cytokinesis. AMR constriction is thought to drive efficient plasma membrane ingression as well as to guide PS formation, whereas PS formation is thought to stabilize the AMR during its constriction. Following the completion of the PS formation, two secondary septa (SS), consisting of glucans and mannoproteins, are synthesized at both sides of the PS. Degradation of the PS and a part of the SS by a chitinase and glucanases then enables cell separation. In this review, we discuss the mechanics of cytokinesis in budding yeast, highlighting its common and unique features as well as the emerging questions. © 2012 Wiley Periodicals, Inc.


Available from: Erfei Bi, Dec 12, 2014
  • Source
    • "In the budding yeast Saccharomyces cerevisiae, cytokinesis involves actomyosin contractile ring closure and septum formation at the mother–bud neck (Bi et al., 1998). The actomyosin ring contains actin filaments formed by formin-dependent processes (Fang et al., 2010; Wloka and Bi, 2012). "
    [Show abstract] [Hide abstract]
    ABSTRACT: While actomyosin and septin ring organization and function in cytokinesis are thoroughly described, little is known regarding the mechanisms whereby the actomyosin ring interacts with septins and associated proteins to coordinate cell division. Here, we show that the protein product of YPL158C, Aim44p, undergoes septin-dependent recruitment to the site of cell division. Aim44p colocalizes with Myo1p, the type II myosin of the contractile ring, throughout most of the cell cycle. The Aim44p ring does not contract when the actomyosin ring closes. Instead, it forms a double ring that associates with septin rings on mother and daughter cells after cell separation. Deletion of AIM44 results in defects in contractile ring closure. Aim44p coimmunoprecipitates with Hof1p, a conserved F-BAR protein that binds both septins and type II myosins and promotes contractile ring closure. Deletion of AIM44 results in a delay in Hof1p phosphorylation, and altered Hof1p localization. Finally, overexpression of Dbf2p, a kinase that phosphorylates Hof1p and is required for relocalization of Hof1p from septin rings to the contractile ring and for Hof1p-triggered contractile ring closure, rescues the cytokinesis defect observed in aim44 cells. Our studies reveal a novel role for Aim44p in regulating contractile ring closure through effects on Hof1p.
    Molecular biology of the cell 01/2014; 25(6). DOI:10.1091/mbc.E13-06-0317 · 4.47 Impact Factor
  • Source
    • "during cleavage-furrow ingression Cyk3 was originally identified as a dosage suppressor of iqg1 (Korinek et al., 2000), and its overexpression has been found to promote PS formation in both wild-type and mutant (hof1, myo1, inn1, and a hypomorphic chs2 mutation) strains (our unpublished data; Nishihama et al., 2009; Oh et al., 2012; Wloka and Bi, 2012). Subsequent studies have shown that binding of the SH3 domain and PXXP motifs of Cyk3 to Inn1 and Hof1, respectively, is important for PS formation (unpublished data; Nishihama et al., 2009; Meitinger et al., 2011). "
    [Show abstract] [Hide abstract]
    ABSTRACT: In yeast and animal cytokinesis, the small guanosine triphosphatase (GTPase) Rho1/RhoA has an established role in formation of the contractile actomyosin ring, but its role, if any, during cleavage-furrow ingression and abscission is poorly understood. Through genetic screens in yeast, we found that either activation of Rho1 or inactivation of another small GTPase, Cdc42, promoted secondary septum (SS) formation, which appeared to be responsible for abscission. Consistent with this hypothesis, a dominant-negative Rho1 inhibited SS formation but not cleavage-furrow ingression or the concomitant actomyosin ring constriction. Moreover, Rho1 is temporarily inactivated during cleavage-furrow ingression; this inactivation requires the protein Cyk3, which binds Rho1-guanosine diphosphate via its catalytically inactive transglutaminase-like domain. Thus, unlike the active transglutaminases that activate RhoA, the multidomain protein Cyk3 appears to inhibit activation of Rho1 (and thus SS formation), while simultaneously promoting cleavage-furrow ingression through primary septum formation. This work suggests a general role for the catalytically inactive transglutaminases of fungi and animals, some of which have previously been implicated in cytokinesis.
    The Journal of Cell Biology 07/2013; 202(2):311-29. DOI:10.1083/jcb.201302001 · 9.83 Impact Factor
  • Source
    • "The presence of a cell wall outside the plasma membrane in fungi means that membrane ingression during cytokinesis is coupled tightly to the synthesis of primary and secondary septa at the cleavage site, and the subsequent digestion of the primary septum completes cell division in yeast cells [2]. There is an intimate connection between the actomyosin ring and septum formation in yeasts, such that the actin ring guides the efficient formation of a primary septum, and septum formation stabilises the contracting ring [3], [4], [5], [6]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: The Hof1 protein (Homologue of Fifteen) regulates formation of the primary septum during cytokinesis in the budding yeast , whereas the orthologous Cdc15 protein in fission yeast regulates the actomyosin ring by using its F-BAR domain to recruit actin nucleators to the cleavage site. Here we show that budding yeast Hof1 also contributes to actin ring assembly in parallel with the Rvs167 protein. Simultaneous deletion of the and genes is lethal, and cells fail to assemble the actomyosin ring as they progress through mitosis. Although Hof1 and Rvs167 are not orthologues, they both share an analogous structure, with an F-BAR or BAR domain at the amino terminus, capable of inducing membrane curvature, and SH3 domains at the carboxyl terminus that bind to specific proline-rich targets. The SH3 domain of Rvs167 becomes essential for assembly of the actomyosin ring in cells lacking Hof1, suggesting that it helps to recruit a regulator of the actin cytoskeleton. This new function of Rvs167 appears to be independent of its known role as a regulator of the Arp2/3 actin nucleator, as actin ring assembly is not abolished by the simultaneous inactivation of Hof1 and Arp2/3. Instead we find that recruitment to the bud-neck of the Iqg1 actin regulator is defective in cells lacking Hof1 and Rvs167, though future studies will be needed to determine if this reflects a direct interaction between these factors. The redundant role of Hof1 in actin ring assembly suggests that the mechanism of actin ring assembly has been conserved to a greater extent across evolution than anticipated previously.
    PLoS ONE 02/2013; 8(2):e57846. DOI:10.1371/journal.pone.0057846 · 3.23 Impact Factor
Show more