Mutational effect of fission yeast polalpha on cell cycle events.


:Polalpha is the principal DNA polymerase for initiation of DNA replication and also functions in postinitiation DNA synthesis. In this study, we investigated the cell cycle responses induced by mutations in polalpha+. Germinating spores carrying either a deletion of polalpha+ (polalphaDelta) or a structurally intact but catalytically dead polalpha mutation proceed to inappropriate mitosis with no DNA synthesis. This suggests that the catalytic function, and not the physical presence of Polalpha, is required to generate the signal that prevents the cells from entering mitosis prematurely. Cells with a polalphats allele arrest the cell cycle near the hydroxyurea arrest point, but, surprisingly, polalphats in cdc20 (polepsilon mutant) background arrested with a cdc phenoytpe, not a polalphats-like phenotype. At 25 degrees C, replication perturbation caused by polalphats alleles induces Cds1 kinase activity and requires the checkpoint Rads, Cds1, and Rqh1, but not Chk1, to maintain cell viability. At 36 degrees C, replication disruption caused by polalphats alleles induces the phosphorylation of Chk1; however, mutant cells arrest with heterogeneous cell sizes with a population of the cells entering aberrant mitosis. Together, our results indicate that the initiation DNA structure synthesized by Polalpha is required to bring about the S phase to mitosis checkpoint, whereas replication defects of different severity caused by polalphats mutations induce differential downstream kinase responses.


Mol Biol Cell


Bhaumik D,Wang TS




Has Abstract


1998-08-01 00:00:00












  • Biochemical and biological analysis of Mek1 phosphorylation site mutants.

    abstract::Recently, we described the constitutive activation of Mek1 by mutation of its two serine phosphorylation sites. We have now characterized the biochemical properties of these Mek1 mutants and performed microinjection experiments to investigate the effect of an activated Mek on oocyte maturation. Single acidic substitut...

    journal_title:Molecular biology of the cell

    pub_type: 杂志文章


    authors: Huang W,Kessler DS,Erikson RL

    更新日期:1995-03-01 00:00:00

  • Dissection of Swa2p/auxilin domain requirements for cochaperoning Hsp70 clathrin-uncoating activity in vivo.

    abstract::The auxilin family of J-domain proteins load Hsp70 onto clathrin-coated vesicles (CCVs) to drive uncoating. In vitro, auxilin function requires its ability to bind clathrin and stimulate Hsp70 ATPase activity via its J-domain. To test these requirements in vivo, we performed a mutational analysis of Swa2p, the yeast a...

    journal_title:Molecular biology of the cell

    pub_type: 杂志文章


    authors: Xiao J,Kim LS,Graham TR

    更新日期:2006-07-01 00:00:00

  • Translationally repressed mRNA transiently cycles through stress granules during stress.

    abstract::In mammals, repression of translation during stress is associated with the assembly of stress granules in the cytoplasm, which contain a fraction of arrested mRNA and have been proposed to play a role in their storage. Because physical contacts are seen with GW bodies, which contain the mRNA degradation machinery, str...

    journal_title:Molecular biology of the cell

    pub_type: 杂志文章


    authors: Mollet S,Cougot N,Wilczynska A,Dautry F,Kress M,Bertrand E,Weil D

    更新日期:2008-10-01 00:00:00

  • Roles of polymerization dynamics, opposed motors, and a tensile element in governing the length of Xenopus extract meiotic spindles.

    abstract::Metaphase spindles assemble to a steady state in length by mechanisms that involve microtubule dynamics and motor proteins, but they are incompletely understood. We found that Xenopus extract spindles recapitulate the length of egg meiosis II spindles, by using mechanisms intrinsic to the spindle. To probe these mecha...

    journal_title:Molecular biology of the cell

    pub_type: 杂志文章


    authors: Mitchison TJ,Maddox P,Gaetz J,Groen A,Shirasu M,Desai A,Salmon ED,Kapoor TM

    更新日期:2005-06-01 00:00:00

  • Characterizing the roles of Met31 and Met32 in coordinating Met4-activated transcription in the absence of Met30.

    abstract::Yeast sulfur metabolism is transcriptionally regulated by the activator Met4. Met4 lacks DNA-binding ability and relies on interactions with Met31 and Met32, paralogous proteins that bind the same cis-regulatory element, to activate its targets. Although Met31 and Met32 are redundant for growth in the absence of methi...

    journal_title:Molecular biology of the cell

    pub_type: 杂志文章


    authors: Carrillo E,Ben-Ari G,Wildenhain J,Tyers M,Grammentz D,Lee TA

    更新日期:2012-05-01 00:00:00

  • Apg7p/Cvt2p: A novel protein-activating enzyme essential for autophagy.

    abstract::In the yeast Saccharomyces cerevisiae, the Apg12p-Apg5p conjugating system is essential for autophagy. Apg7p is required for the conjugation reaction, because Apg12p is unable to form a conjugate with Apg5p in the apg7/cvt2 mutant. Apg7p shows a significant similarity to a ubiquitin-activating enzyme, Uba1p. In this a...

    journal_title:Molecular biology of the cell

    pub_type: 杂志文章


    authors: Tanida I,Mizushima N,Kiyooka M,Ohsumi M,Ueno T,Ohsumi Y,Kominami E

    更新日期:1999-05-01 00:00:00

  • A novel selection regime for differentiation defects demonstrates an essential role for the stumpy form in the life cycle of the African trypanosome.

    abstract::A novel selection scheme has been developed to isolate bloodstream forms of Trypanosoma brucei, which are defective in their ability to differentiate to the procyclic stage. Detailed characterization of one selected cell line (defective in differentiation clone 1 [DiD-1]) has demonstrated that these cells are indistin...

    journal_title:Molecular biology of the cell

    pub_type: 杂志文章


    authors: Tasker M,Wilson J,Sarkar M,Hendriks E,Matthews K

    更新日期:2000-05-01 00:00:00

  • Deletion of nudC, a nuclear migration gene of Aspergillus nidulans, causes morphological and cell wall abnormalities and is lethal.

    abstract::Nuclear migration is required for normal development in both higher and lower eukaryotes. In fungi this process is mediated by cytoplasmic dynein. It is believed that this motor protein is anchored to the cell membrane and moves nuclei by capturing and pulling on spindle pole body microtubules. To date, four genes hav...

    journal_title:Molecular biology of the cell

    pub_type: 杂志文章


    authors: Chiu YH,Xiang X,Dawe AL,Morris NR

    更新日期:1997-09-01 00:00:00

  • Regulation of cyclin-dependent kinase 4 translation through CUG-binding protein 1 and microRNA-222 by polyamines.

    abstract::The amino acid-derived polyamines are organic cations that are essential for growth in all mammalian cells, but their exact roles at the molecular level remain largely unknown. Here we provide evidence that polyamines promote the translation of cyclin-dependent kinase 4 (CDK4) by the action of CUG-binding protein 1 (C...

    journal_title:Molecular biology of the cell

    pub_type: 杂志文章


    authors: Xiao L,Cui YH,Rao JN,Zou T,Liu L,Smith A,Turner DJ,Gorospe M,Wang JY

    更新日期:2011-09-01 00:00:00

  • Diacylglycerol kinase ζ regulates RhoA activation via a kinase-independent scaffolding mechanism.

    abstract::Rho GTPases share a common inhibitor, Rho guanine nucleotide dissociation inhibitor (RhoGDI), which regulates their expression levels, membrane localization, and activation state. The selective dissociation of individual Rho GTPases from RhoGDI ensures appropriate responses to cellular signals, but the underlying mech...

    journal_title:Molecular biology of the cell

    pub_type: 杂志文章


    authors: Ard R,Mulatz K,Abramovici H,Maillet JC,Fottinger A,Foley T,Byham MR,Iqbal TA,Yoneda A,Couchman JR,Parks RJ,Gee SH

    更新日期:2012-10-01 00:00:00

  • Cyclin aggregation and robustness of bio-switching.

    abstract::During the cell cycle, Cdc2-cyclin B kinase abruptly becomes active and triggers the entry into mitosis/meiosis. Recently, it was found that inactive Cdc2-cyclin B is present in aggregates in immature starfish oocytes and becomes disaggregated at the time of its activation during maturation. We discuss a possible scen...

    journal_title:Molecular biology of the cell

    pub_type: 杂志文章


    authors: Slepchenko BM,Terasaki M

    更新日期:2003-11-01 00:00:00

  • Novel function of keratins 5 and 14 in proliferation and differentiation of stratified epithelial cells.

    abstract::Keratins are cytoplasmic intermediate filament proteins preferentially expressed by epithelial tissues in a site-specific and differentiation-dependent manner. The complex network of keratin filaments in stratified epithelia is tightly regulated during squamous cell differentiation. Keratin 14 (K14) is expressed in mi...

    journal_title:Molecular biology of the cell

    pub_type: 杂志文章


    authors: Alam H,Sehgal L,Kundu ST,Dalal SN,Vaidya MM

    更新日期:2011-11-01 00:00:00

  • The PEN1 syntaxin defines a novel cellular compartment upon fungal attack and is required for the timely assembly of papillae.

    abstract::Attack by the host powdery mildew Erysiphe cichoracearum usually results in successful penetration and rapid proliferation of the fungus on Arabidopsis. By contrast, the nonhost barley powdery mildew Blumeria graminis f. sp. hordei (Bgh) typically fails to penetrate Arabidopsis epidermal cells. In both instances the p...

    journal_title:Molecular biology of the cell

    pub_type: 杂志文章


    authors: Assaad FF,Qiu JL,Youngs H,Ehrhardt D,Zimmerli L,Kalde M,Wanner G,Peck SC,Edwards H,Ramonell K,Somerville CR,Thordal-Christensen H

    更新日期:2004-11-01 00:00:00

  • Continual production of phosphatidic acid by phospholipase D is essential for antigen-stimulated membrane ruffling in cultured mast cells.

    abstract::Phospholipase Ds (PLDs) are regulated enzymes that generate phosphatidic acid (PA), a putative second messenger implicated in the regulation of vesicular trafficking and cytoskeletal reorganization. Mast cells, when stimulated with antigen, show a dramatic alteration in their cytoskeleton and also release their secret...

    journal_title:Molecular biology of the cell

    pub_type: 杂志文章


    authors: O'Luanaigh N,Pardo R,Fensome A,Allen-Baume V,Jones D,Holt MR,Cockcroft S

    更新日期:2002-10-01 00:00:00

  • RSBP-1 is a membrane-targeting subunit required by the Galpha(q)-specific but not the Galpha(o)-specific R7 regulator of G protein signaling in Caenorhabditis elegans.

    abstract::Regulator of G protein signaling (RGS) proteins inhibit G protein signaling by activating Galpha GTPase activity, but the mechanisms that regulate RGS activity are not well understood. The mammalian R7 binding protein (R7BP) can interact with all members of the R7 family of RGS proteins, and palmitoylation of R7BP can...

    journal_title:Molecular biology of the cell

    pub_type: 杂志文章


    authors: Porter MY,Koelle MR

    更新日期:2010-01-15 00:00:00

  • Phospholipase A(2) antagonists inhibit nocodazole-induced Golgi ministack formation: evidence of an ER intermediate and constitutive cycling.

    abstract::Evidence has been presented both for and against obligate retrograde movement of resident Golgi proteins through the endoplasmic reticulum (ER) during nocodazole-induced Golgi ministack formation. Here, we studied the nocodazole-induced formation of ministacks using phospholipase A(2) (PLA(2)) antagonists, which have ...

    journal_title:Molecular biology of the cell

    pub_type: 杂志文章


    authors: Drecktrah D,Brown WJ

    更新日期:1999-12-01 00:00:00

  • Centrosomes split in the presence of impaired DNA integrity during mitosis.

    abstract::A well-established function of centrosomes is their role in accomplishing a successful mitosis that gives rise to a pair of identical daughter cells. We recently showed that DNA replication defects and DNA damage in Drosophila embryos trigger centrosomal changes, but it remained unclear whether comparable centrosomal ...

    journal_title:Molecular biology of the cell

    pub_type: 杂志文章


    authors: Hut HM,Lemstra W,Blaauw EH,Van Cappellen GW,Kampinga HH,Sibon OC

    更新日期:2003-05-01 00:00:00

  • Protein kinase Czeta mediates insulin-induced glucose transport through actin remodeling in L6 muscle cells.

    abstract::Protein kinase C (PKC) zeta has been implicated in insulin-induced glucose uptake in skeletal muscle cell, although the underlying mechanism remains unknown. In this study, we investigated the effect of PKCzeta on actin remodeling and glucose transport in differentiated rat L6 muscle cells expressing myc-tagged glucos...

    journal_title:Molecular biology of the cell

    pub_type: 杂志文章


    authors: Liu LZ,Zhao HL,Zuo J,Ho SK,Chan JC,Meng Y,Fang FD,Tong PC

    更新日期:2006-05-01 00:00:00

  • Full-length dimeric MCAK is a more efficient microtubule depolymerase than minimal domain monomeric MCAK.

    abstract::MCAK belongs to the Kinesin-13 family, whose members depolymerize microtubules rather than translocate along them. We defined the minimal functional unit of MCAK as the catalytic domain plus the class specific neck (MD-MCAK), which is consistent with previous reports. We used steady-state ATPase kinetics, microtubule ...

    journal_title:Molecular biology of the cell

    pub_type: 杂志文章


    authors: Hertzer KM,Ems-McClung SC,Kline-Smith SL,Lipkin TG,Gilbert SP,Walczak CE

    更新日期:2006-02-01 00:00:00

  • A role for sorting nexin 2 in epidermal growth factor receptor down-regulation: evidence for distinct functions of sorting nexin 1 and 2 in protein trafficking.

    abstract::Sorting nexin 1 (SNX1) and SNX2, homologues of the yeast vacuolar protein-sorting (Vps)5p, contain a phospholipid-binding motif termed the phox homology (PX) domain and a carboxyl terminal coiled-coil region. A role for SNX1 in trafficking of cell surface receptors from endosomes to lysosomes has been proposed; howeve...

    journal_title:Molecular biology of the cell

    pub_type: 杂志文章


    authors: Gullapalli A,Garrett TA,Paing MM,Griffin CT,Yang Y,Trejo J

    更新日期:2004-05-01 00:00:00

  • The DNA helicase activity of BLM is necessary for the correction of the genomic instability of bloom syndrome cells.

    abstract::Bloom syndrome (BS) is a rare autosomal recessive disorder characterized by growth deficiency, immunodeficiency, genomic instability, and the early development of cancers of many types. BLM, the protein encoded by BLM, the gene mutated in BS, is localized in nuclear foci and absent from BS cells. BLM encodes a DNA hel...

    journal_title:Molecular biology of the cell

    pub_type: 杂志文章


    authors: Neff NF,Ellis NA,Ye TZ,Noonan J,Huang K,Sanz M,Proytcheva M

    更新日期:1999-03-01 00:00:00

  • The two SAS-6 homologs in Tetrahymena thermophila have distinct functions in basal body assembly.

    abstract::Cilia and flagella are structurally and functionally conserved organelles present in basal as well as higher eukaryotes. The assembly of cilia requires a microtubule based scaffold called a basal body. The ninefold symmetry characteristic of basal bodies and the structurally similar centriole is organized around a hub...

    journal_title:Molecular biology of the cell

    pub_type: 杂志文章


    authors: Culver BP,Meehl JB,Giddings TH Jr,Winey M

    更新日期:2009-03-01 00:00:00

  • Human chromosomes 9, 12, and 15 contain the nucleation sites of stress-induced nuclear bodies.

    abstract::We previously reported the identification of a novel nuclear compartment detectable in heat-shocked HeLa cells that we termed stress-induced Src-activated during mitosis nuclear body (SNB). This structure is the recruitment center for heat shock factor 1 and for a number of RNA processing factors, among a subset of Se...

    journal_title:Molecular biology of the cell

    pub_type: 杂志文章


    authors: Denegri M,Moralli D,Rocchi M,Biggiogera M,Raimondi E,Cobianchi F,De Carli L,Riva S,Biamonti G

    更新日期:2002-06-01 00:00:00

  • The actin-microtubule cross-linking activity of Drosophila Short stop is regulated by intramolecular inhibition.

    abstract::Actin and microtubule dynamics must be precisely coordinated during cell migration, mitosis, and morphogenesis--much of this coordination is mediated by proteins that physically bridge the two cytoskeletal networks. We have investigated the regulation of the Drosophila actin-microtubule cross-linker Short stop (Shot),...

    journal_title:Molecular biology of the cell

    pub_type: 杂志文章


    authors: Applewhite DA,Grode KD,Duncan MC,Rogers SL

    更新日期:2013-09-01 00:00:00

  • Transition of responsive mechanosensitive elements from focal adhesions to adherens junctions on epithelial differentiation.

    abstract::The skin's epidermis is a multilayered epithelial tissue and the first line of defense against mechanical stress. Its barrier function depends on an integrated assembly and reorganization of cell-matrix and cell-cell junctions in the basal layer and on different intercellular junctions in suprabasal layers. However, h...

    journal_title:Molecular biology of the cell

    pub_type: 杂志文章


    authors: Noethel B,Ramms L,Dreissen G,Hoffmann M,Springer R,Rübsam M,Ziegler WH,Niessen CM,Merkel R,Hoffmann B

    更新日期:2018-09-15 00:00:00

  • Two functionally identical modular enhancers in Drosophila troponin T gene establish the correct protein levels in different muscle types.

    abstract::The control of muscle-specific expression is one of the principal mechanisms by which diversity is generated among muscle types. In an attempt to elucidate the regulatory mechanisms that control fiber diversity in any given muscle, we have focused our attention on the transcriptional regulation of the Drosophila Tropo...

    journal_title:Molecular biology of the cell

    pub_type: 杂志文章


    authors: Mas JA,García-Zaragoza E,Cervera M

    更新日期:2004-04-01 00:00:00

  • Selective inactivation of a Fas-associated death domain protein (FADD)-dependent apoptosis and autophagy pathway in immortal epithelial cells.

    abstract::Although evasion of apoptosis is thought to be required for the development of cancer, it is unclear which cell death pathways are evaded. We previously identified a novel epithelial cell death pathway that works in normal cells but is inactivated in tumor cells, implying that it may be targeted during tumor developme...

    journal_title:Molecular biology of the cell

    pub_type: 杂志文章


    authors: Thorburn J,Moore F,Rao A,Barclay WW,Thomas LR,Grant KW,Cramer SD,Thorburn A

    更新日期:2005-03-01 00:00:00

  • LIMK1 regulates Golgi dynamics, traffic of Golgi-derived vesicles, and process extension in primary cultured neurons.

    abstract::In this study, we examined the subcellular distribution and functions of LIMK1 in developing neurons. Confocal microscopy, subcellular fractionation, and expression of several epitope-tagged LIMK1 constructs revealed that LIMK1 is enriched in the Golgi apparatus and growth cones, with the LIM domain required for Golgi...

    journal_title:Molecular biology of the cell

    pub_type: 杂志文章


    authors: Rosso S,Bollati F,Bisbal M,Peretti D,Sumi T,Nakamura T,Quiroga S,Ferreira A,Cáceres A

    更新日期:2004-07-01 00:00:00

  • Identification of xenopus CENP-A and an associated centromeric DNA repeat.

    abstract::Kinetochores are the proteinaceous complexes that assemble on centromeric DNA and direct eukaryotic chromosome segregation. The mechanisms by which higher eukaryotic cells define centromeres are poorly understood. Possible molecular contributors to centromere specification include the underlying DNA sequences and epig...

    journal_title:Molecular biology of the cell

    pub_type: 杂志文章


    authors: Edwards NS,Murray AW

    更新日期:2005-04-01 00:00:00

  • Regulation of telomere length by checkpoint genes in Schizosaccharomyces pombe.

    abstract::We have studied telomere length in Schizosaccharomyces pombe strains carrying mutations affecting cell cycle checkpoints, DNA repair, and regulation of the Cdc2 protein kinase. Telomere shortening was found in rad1, rad3, rad17, and rad26 mutants. Telomere lengths in previously characterized rad1 mutants paralleled th...

    journal_title:Molecular biology of the cell

    pub_type: 杂志文章


    authors: Dahlen M,Olsson T,Kanter-Smoler G,Ramne A,Sunnerhagen P

    更新日期:1998-03-01 00:00:00