A conserved role for kinesin-5 in plant mitosis
... spindle requires opposing forces, generated by motor proteins pushing in opposite directions on spindle microtubules. At the mid-zone, plus-end-directed motors push the poles apart by cross-linking anti-parallel microtubules and walking to their plus ends; while at the pole, minus-end-directed motor ...
... spindle requires opposing forces, generated by motor proteins pushing in opposite directions on spindle microtubules. At the mid-zone, plus-end-directed motors push the poles apart by cross-linking anti-parallel microtubules and walking to their plus ends; while at the pole, minus-end-directed motor ...
Arabidopsis Kinetochore Fiber-Associated MAP65-4
... attach the kinetochore MTs to a spindle pole body or a centrosome. Instead, pole focusing of the kinotochore fibers has been proposed to rely on minus end–directed motors that may form cross-links between individual MTs (Smirnova et al., 1998; Chen, 2002; Ambrose et al., 2005). Selective cross-linki ...
... attach the kinetochore MTs to a spindle pole body or a centrosome. Instead, pole focusing of the kinotochore fibers has been proposed to rely on minus end–directed motors that may form cross-links between individual MTs (Smirnova et al., 1998; Chen, 2002; Ambrose et al., 2005). Selective cross-linki ...
Centromeres: An Integrated Protein/DNA Complex
... is broughtabout by the assemblyof protein subunits into spindle tubules. Thefunctionof the kinetochore,at least in part, is to capturethese spindle microtubulesand generate polewardforces (Mitchison &Kirschner 1985). Several reports indicate that kinetochoresfacilitate microtubulebinding while allow ...
... is broughtabout by the assemblyof protein subunits into spindle tubules. Thefunctionof the kinetochore,at least in part, is to capturethese spindle microtubulesand generate polewardforces (Mitchison &Kirschner 1985). Several reports indicate that kinetochoresfacilitate microtubulebinding while allow ...
Centriole Duplication: Centrin in on Answers? Dispatch
... of the spindle pole body called the ‘half-bridge’ [10], and temperature-sensitive yeast mutants in Cdc31p show defects in spindle pole body duplication [11]. Are centrins required for centriole duplication? Recent evidence, including important new work published recently in Current Biology by Salisb ...
... of the spindle pole body called the ‘half-bridge’ [10], and temperature-sensitive yeast mutants in Cdc31p show defects in spindle pole body duplication [11]. Are centrins required for centriole duplication? Recent evidence, including important new work published recently in Current Biology by Salisb ...
+TIPs and Microtubule Regulation. The Beginning of the Plus End in
... 170 (CLIP-170)-green fluorescent protein (GFP) in living mammalian cells. The fusion protein formed a comet that tracked the plus ends of growing MTs (Perez et al., 1999), and this property is now the defining characteristic of a family of proteins called 1TIPs. The number of 1TIPs, many structurall ...
... 170 (CLIP-170)-green fluorescent protein (GFP) in living mammalian cells. The fusion protein formed a comet that tracked the plus ends of growing MTs (Perez et al., 1999), and this property is now the defining characteristic of a family of proteins called 1TIPs. The number of 1TIPs, many structurall ...
Janice Evans
... • Fertilization by one and only one sperm (prevention of polyspermy) • Appropriate meiotic divisions – Oocyte meiotic maturation • prophase I to metaphase II ...
... • Fertilization by one and only one sperm (prevention of polyspermy) • Appropriate meiotic divisions – Oocyte meiotic maturation • prophase I to metaphase II ...
Ciliary Microtubule Capping Structures Contain A
... in the axonemal fraction. The 34-kD polypeptide that occasionally stained in the capping or axonemal fraction was not stained with the affinity-purified antibody. To insure that the antibodies to the 97-kD polypeptide were not directed against carbohydrates, which could be collected near the membran ...
... in the axonemal fraction. The 34-kD polypeptide that occasionally stained in the capping or axonemal fraction was not stained with the affinity-purified antibody. To insure that the antibodies to the 97-kD polypeptide were not directed against carbohydrates, which could be collected near the membran ...
The DNA helicase ChlR1 is required for sister chromatid cohesion in
... necessary for the establishment of cohesion during DNA replication but is not directly involved in holding sister chromatids together (Skibbens et al., 1999; Toth et al., 1999). Ctf7p/Eco1p encodes an acetyltransferase that both acetylates itself and proteins within the cohesion complex in vitro (Iv ...
... necessary for the establishment of cohesion during DNA replication but is not directly involved in holding sister chromatids together (Skibbens et al., 1999; Toth et al., 1999). Ctf7p/Eco1p encodes an acetyltransferase that both acetylates itself and proteins within the cohesion complex in vitro (Iv ...
Chromosomes
... • Chromosomes come in pairs because you inherited one copy of the chromosome from your mother and on copy of the ...
... • Chromosomes come in pairs because you inherited one copy of the chromosome from your mother and on copy of the ...
patriciazuk.com
... • there is a link between what is happening inside and outside the cell with the activity of cdk/cyclins • in other words – internal and external signals exert control over cdk/cyclins and the cell cycle • internal signal – e.g. kinetochores not attached to spindle microtubules send a molecular sign ...
... • there is a link between what is happening inside and outside the cell with the activity of cdk/cyclins • in other words – internal and external signals exert control over cdk/cyclins and the cell cycle • internal signal – e.g. kinetochores not attached to spindle microtubules send a molecular sign ...
ch9 FA 11 - Cal State LA
... – GDP-bound tubulin can release only from “plus” end – GDP-bound tubulin cannot release from “minus” end or from central region ...
... – GDP-bound tubulin can release only from “plus” end – GDP-bound tubulin cannot release from “minus” end or from central region ...
Microtubules do not promote mitotic slippage when the spindle
... abnormal spindles. Then, when the concentration reaches the upper range limit, the percentage of cells in mitosis reaches its maximum (90–100%), even as the drug concentration is increased further. At this point, HeLa are blocked in mitosis for at least 18–20 h, whether they enter mitosis in concent ...
... abnormal spindles. Then, when the concentration reaches the upper range limit, the percentage of cells in mitosis reaches its maximum (90–100%), even as the drug concentration is increased further. At this point, HeLa are blocked in mitosis for at least 18–20 h, whether they enter mitosis in concent ...
1. What is the product of mitosis? 2.What is the product of meiosis?
... • You need to know: • Structure of DNA • Structures from DNA -> Chromosome • Steps of protein synthesis • Organelles involved in protein synthesis • How cancer occurs ...
... • You need to know: • Structure of DNA • Structures from DNA -> Chromosome • Steps of protein synthesis • Organelles involved in protein synthesis • How cancer occurs ...
Mitosis vs. Meiosis - Ms. Ottolini`s Biology Wiki!
... division were first recognized from examinations of fixed slides of tissues undergoing division. On fixed slides, cells are captured or frozen at particular points in the division cycle. Using these static slides, early microscopists identified specific arrangements or patterns of chromosomes that o ...
... division were first recognized from examinations of fixed slides of tissues undergoing division. On fixed slides, cells are captured or frozen at particular points in the division cycle. Using these static slides, early microscopists identified specific arrangements or patterns of chromosomes that o ...
Mob4 plays a role in spindle focusing in Drosophila S2 cells
... The characteristic bipolar shape of the mitotic spindle is produced by the focusing of the minus ends of microtubules at the spindle poles. The focus is maintained by the centrosome, a microtubule-nucleating organelle, as well as by proteins that are capable of focusing kinetochore fibers (K fibers) ...
... The characteristic bipolar shape of the mitotic spindle is produced by the focusing of the minus ends of microtubules at the spindle poles. The focus is maintained by the centrosome, a microtubule-nucleating organelle, as well as by proteins that are capable of focusing kinetochore fibers (K fibers) ...
Mitosis - RuthenbergAP
... • Cytokinesis in plants, which have cell walls, involves a completely different mechanism. • During telophase, vesicles from the Golgi coalesce at the metaphase plate, forming a cell plate. • The plate enlarges until its membranes fuse with the plasma membrane at the perimeter, with the contents of ...
... • Cytokinesis in plants, which have cell walls, involves a completely different mechanism. • During telophase, vesicles from the Golgi coalesce at the metaphase plate, forming a cell plate. • The plate enlarges until its membranes fuse with the plasma membrane at the perimeter, with the contents of ...
Augmin Plays a Critical Role in Organizing the
... In higher plant cells, microtubules (MTs) are nucleated and organized in a centrosome-independent manner. It is unclear whether augmin-dependent mechanisms underlie spindle MT organization in plant cells as they do in animal cells. When AUGMIN subunit3 (AUG3), which encodes a homolog of animal dim g ...
... In higher plant cells, microtubules (MTs) are nucleated and organized in a centrosome-independent manner. It is unclear whether augmin-dependent mechanisms underlie spindle MT organization in plant cells as they do in animal cells. When AUGMIN subunit3 (AUG3), which encodes a homolog of animal dim g ...
The Role of Model Organisms in the History of Mitosis
... somewhat ambiguous because the initiation of prophase is difficult to define in some cells. Although the activation of cyclin-dependent kinase 1 (CDK1) protein kinase and two other protein kinases, polo and aurora B, are generally accepted as biochemical markers for the onset of mitosis, it should b ...
... somewhat ambiguous because the initiation of prophase is difficult to define in some cells. Although the activation of cyclin-dependent kinase 1 (CDK1) protein kinase and two other protein kinases, polo and aurora B, are generally accepted as biochemical markers for the onset of mitosis, it should b ...
Four new subunits of the Dam1Duo1 complex reveal novel functions
... as a third component of the Duo1p±Dam1p complex (Enquist-Newman et al., 2001), raising the possibility that this complex contains yet more subunits. In the G1 phase of the cell cycle, the budding yeast centromeres are clustered near SPBs through the binding of kinetochores to MTs (Jin et al., 2000). ...
... as a third component of the Duo1p±Dam1p complex (Enquist-Newman et al., 2001), raising the possibility that this complex contains yet more subunits. In the G1 phase of the cell cycle, the budding yeast centromeres are clustered near SPBs through the binding of kinetochores to MTs (Jin et al., 2000). ...
Lab 8 - Meiosis and Gametogenesis
... Part 3: Mammalian Gametogenesis The formation of gametes, or gametogenesis, is the first stage in sexual reproduction. In single-celled organisms, e.g., many Protista, the vegetative cell can simply act as a gamete. In more complex organisms specialized regions within the organism take on the role ...
... Part 3: Mammalian Gametogenesis The formation of gametes, or gametogenesis, is the first stage in sexual reproduction. In single-celled organisms, e.g., many Protista, the vegetative cell can simply act as a gamete. In more complex organisms specialized regions within the organism take on the role ...
Mitotic Disrupter Herbicides
... number of herbicides that specifically disrupt mitosis or cytokinesis as a mechanismof action. The study of the effects of these herbicides has not only shown us much about herbicide action but also which proteins and structuresare required for mitosis in plant cells. Microtubules. Most of the herbi ...
... number of herbicides that specifically disrupt mitosis or cytokinesis as a mechanismof action. The study of the effects of these herbicides has not only shown us much about herbicide action but also which proteins and structuresare required for mitosis in plant cells. Microtubules. Most of the herbi ...
Deep Insight Section Mechanisms of chromosomal instability and carcinogenesis
... the cell cycle, and other processes such as RNA transcription are largely suppressed during mitosis (Egli et al., 2008) so the cell can dedicate its resources to chromosome segregation. Since the cell temporarily suspends some vital processes, the total duration of mitosis is limited. To ensure rapi ...
... the cell cycle, and other processes such as RNA transcription are largely suppressed during mitosis (Egli et al., 2008) so the cell can dedicate its resources to chromosome segregation. Since the cell temporarily suspends some vital processes, the total duration of mitosis is limited. To ensure rapi ...
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.