Spindle pole body-anchored Kar3 drives the nucleus
... application of the core principle that drives nuclear migration in higher cells is used in yeast to drive nuclei toward each other before nuclear fusion. [Keywords: nuclear migration; microtubule; kinesin; karyogamy; spindle pole body; Kar3] Supplemental material is available for this article. Recei ...
... application of the core principle that drives nuclear migration in higher cells is used in yeast to drive nuclei toward each other before nuclear fusion. [Keywords: nuclear migration; microtubule; kinesin; karyogamy; spindle pole body; Kar3] Supplemental material is available for this article. Recei ...
Cell cycle behavior of human HP1 subtypes: distinct
... Intracellular localization of YFP-fused HP1 subtypes We examined the localization of YFP-fusion constructs of human HP1 subtypes in HeLa cells. HeLa cells transiently expressing YFP-fused HP1 were fixed and observed under a fluorescence microscope. In interphase nuclei, YFP-fused HP1 showed two diff ...
... Intracellular localization of YFP-fused HP1 subtypes We examined the localization of YFP-fusion constructs of human HP1 subtypes in HeLa cells. HeLa cells transiently expressing YFP-fused HP1 were fixed and observed under a fluorescence microscope. In interphase nuclei, YFP-fused HP1 showed two diff ...
DNA REPLICATION CHECKPOINT CONTROL 7. Acknowledgments
... importantly, the integrity of the genome must be ensured before it is passed to daughter cells. In unicellular organisms such as yeast, loss of genetic material may lead to cell death. However, in higher eukaryotes genomic instability is causally related with tumorigenesis. To combat this instabilit ...
... importantly, the integrity of the genome must be ensured before it is passed to daughter cells. In unicellular organisms such as yeast, loss of genetic material may lead to cell death. However, in higher eukaryotes genomic instability is causally related with tumorigenesis. To combat this instabilit ...
Targeting of A. thaliana KNL2 to centromeres
... localization of the centromere-specific histone cenH3. Our study revealed a cenH3 nucleosomebinding CENPC-k motif at the C-terminus of Arabidopsis thaliana KNL2, which is conserved among a wide spectrum of eukaryotes. Centromeric localization of KNL2 is abolished by deletion of the CENPC-k motif and ...
... localization of the centromere-specific histone cenH3. Our study revealed a cenH3 nucleosomebinding CENPC-k motif at the C-terminus of Arabidopsis thaliana KNL2, which is conserved among a wide spectrum of eukaryotes. Centromeric localization of KNL2 is abolished by deletion of the CENPC-k motif and ...
Here - Events
... The way mammalian cells coordinate cell growth and cell cycle progression in order to correct for potential mistakes at division and maintain cell size homeostasis is not yet known. Although often hypothesized, the requirement of a size checkpoint similar to that in S. Pombe has not been confirmed e ...
... The way mammalian cells coordinate cell growth and cell cycle progression in order to correct for potential mistakes at division and maintain cell size homeostasis is not yet known. Although often hypothesized, the requirement of a size checkpoint similar to that in S. Pombe has not been confirmed e ...
PAR Proteins Regulate Microtubule Dynamics at
... The PAR Proteins Regulate Microtubule Dynamics at the Cortex The fact that microtubules are more stable at the anterior cortex of the embryo during posterior spindle displacement suggested that PAR proteins could regulate microtubule stability. We set out to test this more directly by looking at mic ...
... The PAR Proteins Regulate Microtubule Dynamics at the Cortex The fact that microtubules are more stable at the anterior cortex of the embryo during posterior spindle displacement suggested that PAR proteins could regulate microtubule stability. We set out to test this more directly by looking at mic ...
Interaction of Antiparallel Microtubules in the
... MAP65-3, and thus likely was null (Caillaud et al., 2008). Similar amounts of proteins extracted from the dyc283 seedlings, as indicated by the reference antiactin bands, were probed with the anti-MAP65-3 antibodies. No signal was detected at the position corresponding to the At MAP65-3 band, confir ...
... MAP65-3, and thus likely was null (Caillaud et al., 2008). Similar amounts of proteins extracted from the dyc283 seedlings, as indicated by the reference antiactin bands, were probed with the anti-MAP65-3 antibodies. No signal was detected at the position corresponding to the At MAP65-3 band, confir ...
Micromechanical studies of mitotic chromosomes
... diameter, possibly with a helical structure. However, little else about supranucleosomal organization (‘higherorder chromatin structure’) is solidly understood. This is a result of the relative softness of chromatin fiber, which leads to chromatin’s apparent flexible-polymer properties (Cui and Bustam ...
... diameter, possibly with a helical structure. However, little else about supranucleosomal organization (‘higherorder chromatin structure’) is solidly understood. This is a result of the relative softness of chromatin fiber, which leads to chromatin’s apparent flexible-polymer properties (Cui and Bustam ...
Shaping mitotic chromosomes: From classical concepts to molecular
... Similarly, the 30 nm fibers observed by conventional EM might have resulted from isolating chromosomes in low Mg2þ conditions or from the fixation process. While it is still conceivable that small stretches of chromatin assemble into 30 nm arrays even within native mitotic chromosomes, these new dat ...
... Similarly, the 30 nm fibers observed by conventional EM might have resulted from isolating chromosomes in low Mg2þ conditions or from the fixation process. While it is still conceivable that small stretches of chromatin assemble into 30 nm arrays even within native mitotic chromosomes, these new dat ...
Human microcephaly ASPM protein is a spindle pole
... In addition to Drosophila Asp, several factors have been identified to play a role in spindle MT focusing, such as motor proteins (dynein and kinesin-14) and the MT minus-end-localised protein NuMA (Gaglio et al., 1996; Goshima et al., 2005; Hatsumi and Endow, 1992; Manning and Compton, 2007; Merdes ...
... In addition to Drosophila Asp, several factors have been identified to play a role in spindle MT focusing, such as motor proteins (dynein and kinesin-14) and the MT minus-end-localised protein NuMA (Gaglio et al., 1996; Goshima et al., 2005; Hatsumi and Endow, 1992; Manning and Compton, 2007; Merdes ...
Protein phosphatases and the regulation of mitosis
... Fig. 2. PPP holoenzymes and substrate selectivity. (A)Schematic showing PPP subunit composition. PP1 catalytic subunits (C) associate with a single regulatory subunit (R) drawn from a pool of over 150 potential partners. PP2A has a trimeric structure, with one each of the two possible catalytic and ...
... Fig. 2. PPP holoenzymes and substrate selectivity. (A)Schematic showing PPP subunit composition. PP1 catalytic subunits (C) associate with a single regulatory subunit (R) drawn from a pool of over 150 potential partners. PP2A has a trimeric structure, with one each of the two possible catalytic and ...
Sampathkumar-2011-Live Cell Imaging Re - Max
... between the actin and MT cytoskeletons in that alteration of actin assembly or turnover, as perturbed by jasplakinolide, was correlated with loss of MT organization, and stabilized AFs were found to align with and move along MTs. Cortical AFs Transiently Coalign with MTs The alignment between fragme ...
... between the actin and MT cytoskeletons in that alteration of actin assembly or turnover, as perturbed by jasplakinolide, was correlated with loss of MT organization, and stabilized AFs were found to align with and move along MTs. Cortical AFs Transiently Coalign with MTs The alignment between fragme ...
Live Cell Imaging Reveals Structural Associations
... between the actin and MT cytoskeletons in that alteration of actin assembly or turnover, as perturbed by jasplakinolide, was correlated with loss of MT organization, and stabilized AFs were found to align with and move along MTs. Cortical AFs Transiently Coalign with MTs The alignment between fragme ...
... between the actin and MT cytoskeletons in that alteration of actin assembly or turnover, as perturbed by jasplakinolide, was correlated with loss of MT organization, and stabilized AFs were found to align with and move along MTs. Cortical AFs Transiently Coalign with MTs The alignment between fragme ...
Nucleation and Dynamics of Golgi-derived Microtubules
... listed molecules has been demonstrated to attenuate Golgiderived MT formation. Most significantly, AKAP450 has proven to be essential for Golgi-derived MT formation in multiple experimental systems and organisms (Rivero et al., 2009; Hurtado et al., 2011; Ori-Mckenney et al., 2012; Maia et al., 2013 ...
... listed molecules has been demonstrated to attenuate Golgiderived MT formation. Most significantly, AKAP450 has proven to be essential for Golgi-derived MT formation in multiple experimental systems and organisms (Rivero et al., 2009; Hurtado et al., 2011; Ori-Mckenney et al., 2012; Maia et al., 2013 ...
Compaction and segregation of sister chromatids via active loop
... First, the chromosomes are condensed into elongated structures that maintain the linear order, i.e. the order of genomic elements in the elongated chromosome resembles their order along the genome (Trask et al., 1993). Second, the compaction machinery is able to distinguish different chromosomes and ...
... First, the chromosomes are condensed into elongated structures that maintain the linear order, i.e. the order of genomic elements in the elongated chromosome resembles their order along the genome (Trask et al., 1993). Second, the compaction machinery is able to distinguish different chromosomes and ...
Functions of the Cdc14-Family Phosphatase Clp1p in the Cell Cycle
... CDK inactivation is degradation of the mitotic cyclin; expression of non- degradable cyclins prevents mitotic exit and cytokinesis in a variety of organisms (Surana et aI., 1993; Wheatley et aI. , 1997; Yamano et aI. , 1996). The mitotic cyclin is ubiquitinated ...
... CDK inactivation is degradation of the mitotic cyclin; expression of non- degradable cyclins prevents mitotic exit and cytokinesis in a variety of organisms (Surana et aI., 1993; Wheatley et aI. , 1997; Yamano et aI. , 1996). The mitotic cyclin is ubiquitinated ...
Asymmetric cell division and axis formation in the embryo
... More recently, live imaging studies have led to a richer description of these relationships and of the dynamics of PAR protein distribution during AP polarity establishment. Imaging of GFP-PAR-6 indicates that whereas the anterior PAR complex (PAR-3/PAR-6/PKC-3) is present throughout the cortex shor ...
... More recently, live imaging studies have led to a richer description of these relationships and of the dynamics of PAR protein distribution during AP polarity establishment. Imaging of GFP-PAR-6 indicates that whereas the anterior PAR complex (PAR-3/PAR-6/PKC-3) is present throughout the cortex shor ...
ROLE OF SPINDLE MICROTUBULES IN THE
... bly is prevented? (b) Reproduction of mitotic centers: Sea urchin eggs normally replicate and split their mitotic centers (spindle poles) at the time of telophase (49, 51). If spindle microtubules are not assembled, do these events follow nuclear envelope breakdown at the normal time or are they del ...
... bly is prevented? (b) Reproduction of mitotic centers: Sea urchin eggs normally replicate and split their mitotic centers (spindle poles) at the time of telophase (49, 51). If spindle microtubules are not assembled, do these events follow nuclear envelope breakdown at the normal time or are they del ...
Dissection of Cell Division Processes in the One Cell Stage
... et al., 1974; Morris, 1975; Nurse et al., 1976; Hoyt et al., 1990). However, some aspects of cell division are not conserved between simple and complex eukaryotes. For instance, the nuclear envelope does not break down during mitosis in yeast, in contrast to the situation in complex eukaryotes. More ...
... et al., 1974; Morris, 1975; Nurse et al., 1976; Hoyt et al., 1990). However, some aspects of cell division are not conserved between simple and complex eukaryotes. For instance, the nuclear envelope does not break down during mitosis in yeast, in contrast to the situation in complex eukaryotes. More ...
Regulation of tubulin heterodimer partitioning during interphase and
... 4.3 The cytoskeleton reorganizes during the cell cycle As illustrated in Fig. 2, all parts of the cytoskeleton undergo major reorganizations between interphase and mitosis. The microtubule system, which during interphase is organized into a single array that originates from the centre of the cell, t ...
... 4.3 The cytoskeleton reorganizes during the cell cycle As illustrated in Fig. 2, all parts of the cytoskeleton undergo major reorganizations between interphase and mitosis. The microtubule system, which during interphase is organized into a single array that originates from the centre of the cell, t ...
Inducing chromosome pairing through premature condensation
... activity is increased rather than decreased by the absence of Ph1. Increased cdk activity can be associated with premature chromosome condensation (Furuno et al. 1999). At the onset of meiosis, as the telomeres cluster into a bouquet, axial elements are generated by the condensation of sister chroma ...
... activity is increased rather than decreased by the absence of Ph1. Increased cdk activity can be associated with premature chromosome condensation (Furuno et al. 1999). At the onset of meiosis, as the telomeres cluster into a bouquet, axial elements are generated by the condensation of sister chroma ...
Monopolar spindle attachment of sister chromatids is ensured by two
... that the co-operation of these two mechanisms is required for the high ®delity of monopolar attachment. Fig. 1. Haploid meiosis induced by the mat genes. (A) Changes in nuclear morphology (a) and DNA content (b) of haploid cells containing transcriptionally active mating type genes of the P and M ty ...
... that the co-operation of these two mechanisms is required for the high ®delity of monopolar attachment. Fig. 1. Haploid meiosis induced by the mat genes. (A) Changes in nuclear morphology (a) and DNA content (b) of haploid cells containing transcriptionally active mating type genes of the P and M ty ...
Caryoneme alternative to chromosome and a new caryological
... arisen by the abuse and (or) misuse of the two equivalent prefixes nucleo- (the combining form of nucle-o, from the Latin nucleus) and karyo- or caryo- (the corresponding combining form from the Greek karyon). These two prefixes, followed by, for instance, the word soma (body) allow to coin the comp ...
... arisen by the abuse and (or) misuse of the two equivalent prefixes nucleo- (the combining form of nucle-o, from the Latin nucleus) and karyo- or caryo- (the corresponding combining form from the Greek karyon). These two prefixes, followed by, for instance, the word soma (body) allow to coin the comp ...
Cleavage furrow formation and ingression during animal cytokinesis
... observed in the zyg-9 and tac-1 mutants described above. Finally, if this hypothesis is correct, then one would expect that, if the centrosomes separate farther, multiple or ectopic furrows should form, as observed in microtubule depolymerization experiments. This does not seem to be the case. For e ...
... observed in the zyg-9 and tac-1 mutants described above. Finally, if this hypothesis is correct, then one would expect that, if the centrosomes separate farther, multiple or ectopic furrows should form, as observed in microtubule depolymerization experiments. This does not seem to be the case. For e ...
Requirements for CPC localization during anaphase
... regulates proper chromosome segregation in this phase. B) At the start of anaphase, Esp1p regulates partial release of Cdc14p, leading to dephosphorylation of Sli15p. C) At late anaphase the CPC is located at the midbody. If no chromatin is present at the midbody, the CPC will localize Boi1p and Boi ...
... regulates proper chromosome segregation in this phase. B) At the start of anaphase, Esp1p regulates partial release of Cdc14p, leading to dephosphorylation of Sli15p. C) At late anaphase the CPC is located at the midbody. If no chromatin is present at the midbody, the CPC will localize Boi1p and Boi ...
Kinetochore
The kinetochore /kɪˈnɛtəkɔər/ is the protein structure on chromatids where the spindle fibers attach during cell division to pull sister chromatids apart.The kinetochore forms in eukaryotes, assembles on the centromere and links the chromosome to microtubule polymers from the mitotic spindle during mitosis and meiosis.""Monocentric"" organisms, including vertebrates, fungi, and most plants, have a single centromeric region on each chromosome which assembles one kinetochore. ""Holocentric"" organisms, such as nematodes and some plants, assemble a kinetochore along the entire length of a chromosome.The kinetochore contains two regions: an inner kinetochore, which is tightly associated with the centromere DNA, assembled in a specialized form of chromatin persistent throughout the cell cycle; an outer kinetochore, which interacts with microtubules; the outer kinetochore is a very dynamic structure, with many identical components, which are assembled and functional only during cell division.Kinetochores start, control and supervise the striking movements of chromosomes during cell division. During mitosis, which occurs after chromosomes are duplicated during S phase, two sister chromatids are held together each with its own kinetochore which face in opposing directions and attach to opposite poles of the mitotic spindle. Following the transition from metaphase to anaphase, the sister chromatids separate from each other, and the individual kinetochores on each chromatid drive their movement to the spindle poles that will define the two new daughter cells. Thus, the kinetochore is essential for the chromosome segregation that is classically associated with mitosis and meiosis.Even the simplest kinetochores consist of more than 19 different proteins. Many of these proteins are conserved between eukaryotic species, including a specialized histone H3 variant (called CENP-A or CenH3) which helps the kinetochore associate with DNA. Other proteins in the kinetochore attach it to the microtubules (MTs) of the mitotic spindle. There are also motor proteins, including both dynein and kinesin, which generate forces that move chromosomes during mitosis. Other proteins, such as MAD2 monitor the microtubule attachment as well as the tension between sister kinetochores and activate the spindle checkpoint to arrest the cell cycle when either of these is absent.In summary, kinetochore functions include anchoring of chromosomes to MTs in the spindle, verification of anchoring, activation of the spindle checkpoint and participation in force generation to propel chromosome movement during cell division.On the other hand, MTs are metastable polymers made of α- and β-tubulin, alternating between growing and shrinking phases, a phenomenon known as ""dynamic instability"". MTs are highly dynamic structures, whose behavior is integrated with kinetochore function to control chromosome movement and segregation.