Plants, MEN and SIN

Bedhomme, Mariette; Jouannic, Stéfan; Champion, Antony; Henry, Y.

doi:10.1016/j.plaphy.2007.10.010

Cited by 15 publications

(22 citation statements)

References 40 publications

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“…Cell cycle-dependent centrosomal and midbody localization patterns have now also been reported for IST1 (22) and VPS4 (this study) and for the CHMP4-binding protein, TTC19, which was recently show to translocate together with its binding partner, FYVE-CENT, from centrosomes to midbodies (35). Furthermore, our current study shows that ESCRT-III and VPS4 proteins are required for proper functioning of both centrosomes and midbodies, supporting the idea that the ESCRT pathway and its accessory factors help control multiple steps in the transition from mitosis to cytokinesis, perhaps with parallels to the wellcharacterized mitotic exit and septation initiation networks in yeast and plants (36). Localization of VPS4 to both centrosomes and midbodies seems to imply that the protein functions directly at both sites.…”

Section: Discussionsupporting

confidence: 83%

Human ESCRT-III and VPS4 proteins are required for centrosome and spindle maintenance

Morita¹,

Colf²,

Karren³

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

190

208

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The ESCRT pathway helps mediate the final abscission step of cytokinesis in mammals and archaea. In mammals, two early acting proteins of the ESCRT pathway, ALIX and TSG101, are recruited to the midbody through direct interactions with the phosphoprotein CEP55. CEP55 resides at the centrosome through most of the cell cycle but then migrates to the midbody at the start of cytokinesis, suggesting that the ESCRT pathway may also have centrosomal links. Here, we have systematically analyzed the requirements for late-acting mammalian ESCRT-III and VPS4 proteins at different stages of mitosis and cell division. We found that depletion of VPS4A, VPS4B, or any of the 11 different human ESCRT-III (CHMP) proteins inhibited abscission. Remarkably, depletion of individual ESCRT-III and VPS4 proteins also altered centrosome and spindle pole numbers, producing multipolar spindles (most ESCRT-III/VPS4 proteins) or monopolar spindles (CHMP2A or CHMP5) and causing defects in chromosome segregation and nuclear morphology. VPS4 proteins concentrated at spindle poles during mitosis and then at midbodies during cytokinesis, implying that these proteins function directly at both sites. We conclude that ESCRT-III/VPS4 proteins function at centrosomes to help regulate their maintenance or proliferation and then at midbodies during abscission, thereby helping ensure the ordered progression through the different stages of cell division.T he ESCRT pathway functions across eukaryotes and many archaeal species, where it helps mediate (i) vesicle formation at multivesicular bodies (MVB) (1), (ii) enveloped virus budding (2), and (iii) the abscission stage of cytokinesis (3-7). These seemingly disparate biological processes all involve the resolution of thin, cytoplasm-filled membrane tubules, implying that ESCRT machinery can be recruited to different biological membranes to mediate topologically similar membrane fission events. Most ESCRT pathway proteins function as subunits of five multiprotein complexes, termed the ESCRT-0, -I, -II, -III, and VPS4 complexes. Other ESCRT factors, such as ALIX, function as discrete proteins. Classic studies in yeast have established that the ESCRT components are recruited sequentially to endosomal membranes where they assemble into higher order complexes that mediate protein sorting, membrane remodeling, and fission (8). Initially, early-acting factors such as ESCRT-I, ESCRT-II, and ALIX interact with upstream recruiting factors, concentrate protein cargoes, and help deform membranes (9). These early-acting factors recruit subunits of the ESCRT-III complex, which form filaments within the necks of membrane tubules and mediate membrane fission (10-16). ESCRT-III assemblies, in turn, recruit VPS4 ATPases, which use the energy of ATP hydrolysis to disassemble the ESCRT complexes (10-14, 17).ESCRT-III and VPS4 homologs mediate abscission in hyperthermophilic crenarchaeal species that diverged from eukaryotes several billion years ago, suggesting that cell division may have been the primordial function of the E...

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Section: Discussionsupporting

confidence: 83%

Human ESCRT-III and VPS4 proteins are required for centrosome and spindle maintenance

Morita¹,

Colf²,

Karren³

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

190

208

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“…The core elements of the SIN Spg1p/Tem1p proteins were only observed in the fungi, plant, and Mycetozoa clades. In contrast, metazoan cells do not use the core elements of the SIN or MEN pathways in order to coordinate the termination of cell division with cytokinesis (717).…”

Section: Ras-gtpasesmentioning

confidence: 99%

The Genomes of Three Uneven Siblings: Footprints of the Lifestyles of Three Trichoderma Species

Schmoll

Dattenböck

Carreras-Villaseñor

et al. 2016

Microbiol Mol Biol Rev

163

195

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SUMMARYThe genusTrichodermacontains fungi with high relevance for humans, with applications in enzyme production for plant cell wall degradation and use in biocontrol. Here, we provide a broad, comprehensive overview of the genomic content of these species for “hot topic” research aspects, including CAZymes, transport, transcription factors, and development, along with a detailed analysis and annotation of less-studied topics, such as signal transduction, genome integrity, chromatin, photobiology, or lipid, sulfur, and nitrogen metabolism inT. reesei,T. atroviride, andT. virens, and we open up new perspectives to those topics discussed previously. In total, we covered more than 2,000 of the predicted 9,000 to 11,000 genes of eachTrichodermaspecies discussed, which is >20% of the respective gene content. Additionally, we considered available transcriptome data for the annotated genes. Highlights of our analyses include overall carbohydrate cleavage preferences due to the different genomic contents and regulation of the respective genes. We found light regulation of many sulfur metabolic genes. Additionally, a new Golgi 1,2-mannosidase likely involved inN-linked glycosylation was detected, as were indications for the ability ofTrichodermaspp. to generate hybrid galactose-containingN-linked glycans. The genomic inventory of effector proteins revealed numerous compounds unique toTrichoderma, and these warrant further investigation. We found interesting expansions in theTrichodermagenus in several signaling pathways, such as G-protein-coupled receptors, RAS GTPases, and casein kinases. A particularly interesting feature absolutely unique toT. atrovirideis the duplication of the alternative sulfur amino acid synthesis pathway.

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“…Components of the SIN have been conserved through evolution; in Saccharomyces cerevisiae, the equivalent signaling network is known as the mitotic exit network (MEN), which regulates mitotic exit and is also important for cytokinesis (reviewed by Bedhomme et al 2008;Meitinger et al 2012). The SIN/MEN protein kinases belong to the nuclear DBF-2-related (NDR) and Ste20 families, the mammalian counterparts of which are important in cell proliferation and growth control (Zhang et al 2009;Zhao et al 2011).…”

Section: Septation Initiation Networkmentioning

confidence: 99%

“…Analysis of the localization of SIN proteins and their activity in mutant backgrounds has led to the proposition that the order of action of the SIN proteins in the mitotic cell cycle is Cdc7p-Spg1p, then Sid1p-Cdc14p, and finally Sid2p-Mob1p (Sparks et al 1999;Guertin et al 2000). Active Cdc2p inhibits the SIN early in mitosis, and CDK inactivation is required for septum formation (Yamano et al 1996;He et al 1997;Guertin et al 2000;Chang et al 2001;Dischinger et al 2008).Components of the SIN have been conserved through evolution; in Saccharomyces cerevisiae, the equivalent signaling network is known as the mitotic exit network (MEN), which regulates mitotic exit and is also important for cytokinesis (reviewed by Bedhomme et al 2008;Meitinger et al 2012). The SIN/MEN protein kinases belong to the nuclear DBF-2-related (NDR) and Ste20 families, the mammalian counterparts of which are important in cell proliferation and growth control (Zhang et al 2009;Zhao et al 2011).…”

mentioning

confidence: 99%

Characterization of ypa1 and ypa2, the Schizosaccharomyces pombe Orthologs of the Peptidyl Proyl Isomerases That Activate PP2A, Reveals a Role for Ypa2p in the Regulation of Cytokinesis

Goyal

2012

Genetics

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The Schizosaccharomyces pombe septation initiation network (SIN) regulates cytokinesis. Cdc7p is the first kinase in the core SIN; we have screened genetically for SIN regulators by isolating cold-sensitive suppressors of cdc7-24. Our screen yielded a mutant in SPAC1782.05, one of the two fission yeast orthologs of mammalian phosphotyrosyl phosphatase activator. We have characterized this gene and its ortholog SPAC4F10.04, which we have named ypa2 and ypa1, respectively. We find that Ypa2p is the major form of protein phosphatase type 2A activator in S. pombe. A double ypa1-D ypa2-D null mutant is inviable, indicating that the two gene products have at least one essential overlapping function. Individually, the ypa1 and ypa2 genes are essential for survival only at low temperatures. The ypa2-D mutant divides at a reduced cell size and displays aberrant cell morphology and cytokinesis. Genetic analysis implicates Ypa2p as an inhibitor of the septation initiation network. We also isolated a cold-sensitive allele of ppa2, the major protein phosphatase type 2A catalytic subunit, implicating this enzyme as a regulator of the septation initiation network. SCHIZOSACCHAROMYCES pombe cells take the form of a cylinder capped by hemispherical ends. During interphase, cells grow mainly at their tips. Cell elongation ceases after mitotic commitment, and the cytoskeleton is reorganized in preparation for nuclear and cell division (reviewed by McCully and Robinow 1971;Mitchison and Nurse 1985;Marks et al. 1986;Hagan and Hyams 1988;Hagan 1998). The cell divides by fission after forming a septum in the middle of the cell. The site of division is defined at the onset of mitosis (Daga and Chang 2005), by the formation of an actomyosin contractile ring (CAR), whose assembly continues throughout mitosis (Wu et al. 2003;Pollard 2008;Pollard and Wu 2010). At the end of anaphase, the CAR is thought to guide synthesis of the multilayered division septum (reviewed by (Ishiguro 1998;Sipiczki 2007). Septation Initiation NetworkThe S. pombe septation initiation network (SIN) is a network of protein kinases that is essential for cytokinesis in the mitotic cycle; reviewed by (Gould and Simanis 1997;Simanis 2003;Wolfe and Gould 2005;Goyal et al. 2011). It is tightly regulated through the mitotic cell cycle to assure proper coordination of mitosis and cytokinesis, and during meiosis, where it is essential for spore formation (Krapp et al. 2006). Signaling requires the activity of three protein kinases, each of which has a regulatory subunit (kinase regulator); Cdc7p-Spg1p (Fankhauser and Simanis 1994;Schmidt et al. 1997;Mehta and Gould 2006), Sid1p-Cdc14p (Fankhauser and Simanis 1993;Guertin et al. 2000;Guertin and McCollum 2001), and Sid2p-Mob1p (Sparks et al. 1999;Hou et al. 2000;Salimova et al. 2000). SIN signaling is modulated by the nucleotide status of the GTPase Spg1p (Schmidt et al. 1997;Sohrmann et al. 1998), which is determined by the balance of spontaneous nucleotide exchange, a putative GEF, Etd1p Garcia-Cortes and McCollu...

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Plants, MEN and SIN

Cited by 15 publications

References 40 publications

Human ESCRT-III and VPS4 proteins are required for centrosome and spindle maintenance

Human ESCRT-III and VPS4 proteins are required for centrosome and spindle maintenance

The Genomes of Three Uneven Siblings: Footprints of the Lifestyles of Three Trichoderma Species

Characterization of ypa1 and ypa2, the Schizosaccharomyces pombe Orthologs of the Peptidyl Proyl Isomerases That Activate PP2A, Reveals a Role for Ypa2p in the Regulation of Cytokinesis

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