PtdIns(3)P controls cytokinesis through KIF13A-mediated recruitment of FYVE-CENT to the midbody

Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Montebello, N-0310 Oslo, Norway.
Nature Cell Biology (Impact Factor: 20.06). 03/2010; 12(4):362-71. DOI: 10.1038/ncb2036
Source: PubMed

ABSTRACT Several subunits of the class III phosphatidylinositol-3-OH kinase (PI(3)K-III) complex are known as tumour suppressors. Here we uncover a function for this complex and its catalytic product phosphatidylinositol-3-phosphate (PtdIns(3)P) in cytokinesis. We show that PtdIns(3)P localizes to the midbody during cytokinesis and recruits a centrosomal protein, FYVE-CENT (ZFYVE26), and its binding partner TTC19, which in turn interacts with CHMP4B, an endosomal sorting complex required for transport (ESCRT)-III subunit implicated in the abscission step of cytokinesis. Translocation of FYVE-CENT and TTC19 from the centrosome to the midbody requires another FYVE-CENT-interacting protein, the microtubule motor KIF13A. Depletion of the VPS34 or Beclin 1 subunits of PI(3)K-III causes cytokinesis arrest and an increased number of binucleate and multinucleate cells, in a similar manner to the depletion of FYVE-CENT, KIF13A or TTC19. These results provide a mechanism for the translocation and docking of a cytokinesis regulatory machinery at the midbody.

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    • "In addition, PI(3)P is also central to autophagy in mammalian cells (Petiot et al., 2000) and yeast (Obara and Ohsumi, 2011). More recently, its role in cytokinesis has been demonstrated (Sagona et al., 2010). PI(3)P exercises its effects by recruiting a variety of cytosolic proteins that contain mainly FYVE (FAB1-YOTB-Vac1-EEA1) domains (Kutateladze et al., 1999; Katzmann et al., 2003; Hayakawa et al., 2004) or PX domains (Cheever et al., 2001). "
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    ABSTRACT: Phosphoinositides regulate numerous cellular processes, by recruiting cytosolic effector proteins and acting as membrane signaling entities. The cellular metabolism and localization of phosphoinositides are tightly regulated by distinct lipid kinases and phosphatases. Here, we identify and characterize a unique phosphatidylinositol 3-Kinase (PI3K) in Toxoplasma gondii, a protozoan parasite belonging to the phylum Apicomplexa. Conditional depletion of this enzyme and subsequently of its product, PI(3)P, drastically alters the morphology and inheritance of the apicoplast, an endosymbiontic organelle of algal origin that is a unique feature of many Apicomplexa. We searched the T. gondii genome for PI(3)P binding proteins and identified in total six PX and FYVE-domain containing proteins including a PIKfyve lipid kinase, which phosphorylates PI(3)P into PI(3,5)P2 . While depletion of putative PI(3)P binding proteins shows that they are not essential for parasite growth and apicoplast biology, conditional disruption of PIKfyve induces enlarged apicoplasts, as observed upon the loss of PI(3)P. A similar defect of apicoplast homeostasis was also observed by knocking-down the PIKfyve regulatory protein ArPIKfyve, suggesting that in T. gondii, PI(3)P-related function for the apicoplast might mainly be to serve as a precursor for the synthesis of PI(3,5)P2 . Accordingly, PI3K is conserved in all apicomplexan parasites whereas PIKfyve and ArPIKfyve are absent in Cryptosporidium species which lack an apicoplast, supporting a direct role of PI(3,5)P2 in apicoplast homeostasis. This study enriches the already diverse functions attributed to PI(3,5)P2 in eukaryotic cells and highlights these parasite lipid kinases as potential drug targets.
    Cellular Microbiology 10/2014; 17(4). DOI:10.1111/cmi.12383 · 4.82 Impact Factor
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    • "First, the protein and lipid composition of the plasma membrane is remodeled, which involves vesicular delivery through several parallel trafficking pathways [e.g. Rab35, Rab11-FIP3 (also known as Rab11 family interacting protein 3), phosphatidylinositol 3-phosphate (PI3P), exocyst] (Echard, 2012b; Fielding et al., 2005; Goss and Toomre, 2008; Gromley et al., 2005; Kouranti et al., 2006; Montagnac et al., 2008; Neto et al., 2011; Sagona et al., 2010; Wilson et al., 2005). For instance, the Rab11-and the Rab35-regulated pathways prevent F-actin accumulation at the plasma membrane, and are both required for normal abscission (Chesneau et al., 2012; Dambournet et al., 2011; Echard, 2012a; Schiel et al., 2012). "
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    ABSTRACT: The midbody remnant (MBR) that is generated after cytokinesis abscission has recently attracted a lot of attention, since it may have crucial consequences for cell differentiation and tumorigenesis in mammalian cells. In those cells, it has been reported that the MBR is either released into the extracellular medium, or retracted into one of the two daughter cells where it can be degraded by autophagy. Here, we describe a major alternative pathway in a variety of human and mouse immortalized/cancer and primary stem cells. Using correlative light/scanningEM microscopy and quantitative assays, we found that sequential abscissions on both sides of the midbody generate free MBRs, which are tightly associated to the cell surface through a Ca(++)/Mg(++)-dependent receptor. Surprisingly, MBRs move over the cell surface for several hours, before being eventually engulfed by an actin-dependent phagocytosis-like mechanism. Mathematical modelling combined to experiments further demonstrates that lysosomal activities fully account for clearance of MBRs after engulfment. This study changes our vision of how MBRs are inherited and degraded in mammalian cells, and suggests a mechanism by which MBRs might signal over long distances between cells.
    Journal of Cell Science 07/2014; 127(17). DOI:10.1242/jcs.154732 · 5.33 Impact Factor
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    • "NIH3T3 cells were grown in Quantum 333 medium, containing 2% bovine serum and HLEB-3 cells were grown in Eagle's minimum essential medium (EMEM) containing 20% foetal bovine serum (FBS). Transfection of HeLa cells was performed as described previously [17] "
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    ABSTRACT: Autophagy is a mechanism of cellular self-degradation that is very important for cellular homeostasis and differentiation. Components of the endosomal sorting complex required for transport (ESCRT) machinery are required for endosomal sorting and also for autophagy and the completion of cytokinesis. Here we show that the ESCRT-III subunit CHMP4B not only localizes to normal cytokinetic bridges but also to chromosome bridges and micronuclei, the latter surrounded by lysosomes and autophagosomes. Moreover, CHMP4B can be co-immunoprecipitated with chromatin. Interestingly, a CHMP4B mutation associated with autosomal dominant posterior polar cataract abolishes the ability of CHMP4B to localize to micronuclei. We propose that CHMP4B, through its association with chromatin, may participate in the autophagolysosomal degradation of micronuclei and other extranuclear chromatin. This may have implications for DNA degradation during lens cell differentiation, thus potentially protecting lens cells from cataract development.
    03/2014; 2014:974393. DOI:10.1155/2014/974393
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