Building and Breaking Bridges between Sister Chromatids
... amount of evidence is consistent with the notion that cohesin might be the actual glue between sister chromatids. In yeast, cohesin associates with chromosomes in late G1-phase, remains bound during S- and G2phases and dissociates again at the metaphase to anaphase transition; that is precisely when ...
... amount of evidence is consistent with the notion that cohesin might be the actual glue between sister chromatids. In yeast, cohesin associates with chromosomes in late G1-phase, remains bound during S- and G2phases and dissociates again at the metaphase to anaphase transition; that is precisely when ...
Imaging the fate of histone Cse4 reveals de novo replacement in S
... Figure 2. Pre-existing Cse4 is removed and exchanged for new Cse4 molecules at G1/S transition. (A) Relevant fluorescence states of a tdEos-tagged protein molecule are depicted schematically after its synthesis and folding, fluorophore maturation and irreversible photoconversion. Excitation and emis ...
... Figure 2. Pre-existing Cse4 is removed and exchanged for new Cse4 molecules at G1/S transition. (A) Relevant fluorescence states of a tdEos-tagged protein molecule are depicted schematically after its synthesis and folding, fluorophore maturation and irreversible photoconversion. Excitation and emis ...
Establishment of Polarity during Organization of the Acentrosomal
... EB1a-GFP and EB1b-GFP appeared in a cometlike pattern (1.01 ⫾ 0.11 m for EB1a; 1.11 ⫾ 0.18 m for EB1b; n ⫽ 50; Figure 1, A and B, and Supplementary Movie 2), whereas EB1c-GFP is nuclear (Figure 1C). The cometlike character, with the bright side leading has been shown to be diagnostic of (⫹)-end gr ...
... EB1a-GFP and EB1b-GFP appeared in a cometlike pattern (1.01 ⫾ 0.11 m for EB1a; 1.11 ⫾ 0.18 m for EB1b; n ⫽ 50; Figure 1, A and B, and Supplementary Movie 2), whereas EB1c-GFP is nuclear (Figure 1C). The cometlike character, with the bright side leading has been shown to be diagnostic of (⫹)-end gr ...
Functions of the Arabidopsis kinesin superfamily of microtubule
... by the human genome (45 kinesins) (Reddy and Day 2001; Miki et al. 2005). Bioinformatic analysis has revealed that the inventory of kinesins in plants is distinctive from that of animals, suggesting that kinesins have evolved to perform specialized functions in plants (Reddy and Day 2001; Richardson ...
... by the human genome (45 kinesins) (Reddy and Day 2001; Miki et al. 2005). Bioinformatic analysis has revealed that the inventory of kinesins in plants is distinctive from that of animals, suggesting that kinesins have evolved to perform specialized functions in plants (Reddy and Day 2001; Richardson ...
central spindle and contractile ring for cytokinesis encodes a kinesin
... In addition to the contribution made by the spindle, several proteins, known as the chromosomal passenger proteins, dissociate from chromosomes at the metaphase–anaphase transition to be deposited at the cell equator. The inner centromere proteins (INCENPs), for example, transfer to the central spin ...
... In addition to the contribution made by the spindle, several proteins, known as the chromosomal passenger proteins, dissociate from chromosomes at the metaphase–anaphase transition to be deposited at the cell equator. The inner centromere proteins (INCENPs), for example, transfer to the central spin ...
Linking abnormal mitosis to the acquisition of DNA damage
... so that they can be efficiently and equally partitioned into two daughter cells during mitosis. Numerous checkpoints have evolved to ensure that mitosis only proceeds when growth conditions are ideal and chromosomes are efficiently replicated and free of damage. This level of quality control takes t ...
... so that they can be efficiently and equally partitioned into two daughter cells during mitosis. Numerous checkpoints have evolved to ensure that mitosis only proceeds when growth conditions are ideal and chromosomes are efficiently replicated and free of damage. This level of quality control takes t ...
Expansion of the phragmoplast during plant cytokinesis: a MAPK
... during late anaphase [1]. A phragmoplast complex is composed of two bundles of anti-parallel microtubules (MTs) and actin filaments. MTs are, in general, orientated and consist of a plus end and a minus end. The MTs overlap at their plus ends in the center of the phragmoplast. The initial shape of t ...
... during late anaphase [1]. A phragmoplast complex is composed of two bundles of anti-parallel microtubules (MTs) and actin filaments. MTs are, in general, orientated and consist of a plus end and a minus end. The MTs overlap at their plus ends in the center of the phragmoplast. The initial shape of t ...
REGULATION OF CDC14: PATHWAYS AND CHECKPOINTS OF
... The first such event is the separation of sister-chromatids. After all sister chromatids are attached to microtubules emanating from the two opposing centrosomes (known as spindle pole bodies (SPBs) in yeast), the cohesin protein complex that maintains the sister-chromatid cohesion is removed by pro ...
... The first such event is the separation of sister-chromatids. After all sister chromatids are attached to microtubules emanating from the two opposing centrosomes (known as spindle pole bodies (SPBs) in yeast), the cohesin protein complex that maintains the sister-chromatid cohesion is removed by pro ...
Separation of Sister Chromatids in Mitosis
... observations indicated that the primary defect in pim mutants is a defect in chromosome distribution. pim and thr Are Specifically Required for Sister Chromatid Separation in the Centromeric Region Chromosomes that are not fully replicated cannot be segregated during mitosis. Checkpoint mechanisms n ...
... observations indicated that the primary defect in pim mutants is a defect in chromosome distribution. pim and thr Are Specifically Required for Sister Chromatid Separation in the Centromeric Region Chromosomes that are not fully replicated cannot be segregated during mitosis. Checkpoint mechanisms n ...
Microtubule
... The αβ heterodimer is the basic structural unit of the microtubule. Each subunit has a binding site for one molecule of GTP. Once the αβ dimer is formed, the nucleotide in the alpha subunit (GTP) is buried at the intradimer interface, and it cannot be hydrolyzed. In contrast the nucleotide on the β- ...
... The αβ heterodimer is the basic structural unit of the microtubule. Each subunit has a binding site for one molecule of GTP. Once the αβ dimer is formed, the nucleotide in the alpha subunit (GTP) is buried at the intradimer interface, and it cannot be hydrolyzed. In contrast the nucleotide on the β- ...
DNA Topoisomerase II Must Act at Mitosis to Prevent Nondisjunction
... they are passing through mitosis (13, 37). In other words, topoisomerase II activity appears to be essential only at the time of mitosis. Cytological observations in both organisms show that at the time that viability plummets, chromosome segregation is cytologically abnormal (6, 13, 36, 37). The ob ...
... they are passing through mitosis (13, 37). In other words, topoisomerase II activity appears to be essential only at the time of mitosis. Cytological observations in both organisms show that at the time that viability plummets, chromosome segregation is cytologically abnormal (6, 13, 36, 37). The ob ...
Tansley review - Professor Gero Steinberg
... ability of the hypha to grow invasively. Extended hyphal growth and mitosis require microtubules, as revealed by recent studies on the microtubule cytoskeleton. Surprisingly, hyphal tip growth involves only two out of 10 kinesins. Kinesin-3 is responsible for tip-directed (anterograde) endosome moti ...
... ability of the hypha to grow invasively. Extended hyphal growth and mitosis require microtubules, as revealed by recent studies on the microtubule cytoskeleton. Surprisingly, hyphal tip growth involves only two out of 10 kinesins. Kinesin-3 is responsible for tip-directed (anterograde) endosome moti ...
Female meiosis in polo - Journal of Cell Science
... microtubule array of the central spindle pole body was well developed, the microtubules did not have a well organised focus (Fig. 2A). It appeared that as metaphase progressed in the polo1-derived eggs, the twin spindles moved away from each other, and the central aster expanded as a disorganised ar ...
... microtubule array of the central spindle pole body was well developed, the microtubules did not have a well organised focus (Fig. 2A). It appeared that as metaphase progressed in the polo1-derived eggs, the twin spindles moved away from each other, and the central aster expanded as a disorganised ar ...
Centrosome Biology: A SAS-sy Centriole in the Cell Cycle Dispatch
... fundamental unit of the centrosome. A single centriole can form a centrosome or spindle pole — the yeast equivalent – but it cannot divide to form two centrosomes unless the centriole structure itself is duplicated. If the centrioles are the fundamental units, how are the pericentriolar components a ...
... fundamental unit of the centrosome. A single centriole can form a centrosome or spindle pole — the yeast equivalent – but it cannot divide to form two centrosomes unless the centriole structure itself is duplicated. If the centrioles are the fundamental units, how are the pericentriolar components a ...
Polarity Control of Spindle Positioning in the C. elegans Embryo
... When cells divide, chromosome segregation is followed by cleavage of the cytoplasm. The microtubule spindle apparatus instructs the cytokinetic furrow to form perpendicular to, and usually midway through, the central spindle. By positioning the spindle with respect to the polarity axis of the cell o ...
... When cells divide, chromosome segregation is followed by cleavage of the cytoplasm. The microtubule spindle apparatus instructs the cytokinetic furrow to form perpendicular to, and usually midway through, the central spindle. By positioning the spindle with respect to the polarity axis of the cell o ...
Sister Chromatid Cohesion Control and Aneuploidy
... the resulting gametes. STAG3, REC8, SMC1 meiosis-specific cohesins and RAD21 are also expressed in mammalian fetal oocytes, and their dynamics during early prophase I are similar to that in spermatocytes [Prieto et al., 2005]. Total loss of cohesin signals, as well as of SYCP2 and SYCP3, is nonethe ...
... the resulting gametes. STAG3, REC8, SMC1 meiosis-specific cohesins and RAD21 are also expressed in mammalian fetal oocytes, and their dynamics during early prophase I are similar to that in spermatocytes [Prieto et al., 2005]. Total loss of cohesin signals, as well as of SYCP2 and SYCP3, is nonethe ...
CONDENSIN AND COHESIN: MORE THAN CHROMOSOME
... homologues are paired, cohesin localizes along chromosome arms, but when sister chromatids are paired during meiosis II, cohesin is only found between centromeres88,90,95 –97. Most organisms contain a meiosis-specific cohesin complex, with a meiosis-specific SSC1 variant called REC8 in place of SCC1 ...
... homologues are paired, cohesin localizes along chromosome arms, but when sister chromatids are paired during meiosis II, cohesin is only found between centromeres88,90,95 –97. Most organisms contain a meiosis-specific cohesin complex, with a meiosis-specific SSC1 variant called REC8 in place of SCC1 ...
Localization of the Microtubule End Binding Protein
... unambiguous marker of microtubule nucleation has led to uncertainty about the origin of, and continuity between, the various microtubule arrays. For instance, the absence of centrosomes from the plant cell’s spindle poles has been taken as support for the idea that spindles form by an inside-out mec ...
... unambiguous marker of microtubule nucleation has led to uncertainty about the origin of, and continuity between, the various microtubule arrays. For instance, the absence of centrosomes from the plant cell’s spindle poles has been taken as support for the idea that spindles form by an inside-out mec ...
Genetic Block of Outer Plaque Morphogenesis at the Second Meiotic
... An hfdl-1 mutant of Saccharomyces cerevisiae, SOS4, characterized by predominant production of two-spored asci at 29 " C , undergoes normal meiotic nuclear divisions and produces four haploid nuclei, but only two non-sister nuclei among them are incorporated into mature ascospores. Spindle pole bodi ...
... An hfdl-1 mutant of Saccharomyces cerevisiae, SOS4, characterized by predominant production of two-spored asci at 29 " C , undergoes normal meiotic nuclear divisions and produces four haploid nuclei, but only two non-sister nuclei among them are incorporated into mature ascospores. Spindle pole bodi ...
File
... – Molecular motors move unidirectionally along their cytoskeletal track in a stepwise manner. – Three categories of molecular motors: • Kinesin and dynein move along microtubule tracks. • Myosin moves along microfilament tracks. ...
... – Molecular motors move unidirectionally along their cytoskeletal track in a stepwise manner. – Three categories of molecular motors: • Kinesin and dynein move along microtubule tracks. • Myosin moves along microfilament tracks. ...
Tetrazine−trans-cyclooctene Mediated Conjugation of Antibodies to
... of the bonds under tension19 as well as at high gliding velocities,20 and reduced velocity of transport.21 The noncovalent biotin−streptavidin interaction is short-ranged and reversible, limiting its practical applications: examples are an almost million fold increase in the dissociation constant (K ...
... of the bonds under tension19 as well as at high gliding velocities,20 and reduced velocity of transport.21 The noncovalent biotin−streptavidin interaction is short-ranged and reversible, limiting its practical applications: examples are an almost million fold increase in the dissociation constant (K ...
The TACC proteins: TACC-ling microtubule dynamics and
... dynamic nature of the cytoskeletal components. Microtubules are dynamic filaments with fundamental roles in eukaryotic cell organization and function. During cell division, they form the bipolar spindle, which segregates the chromosomes into the two daughter cells. Microtubules show prolonged states ...
... dynamic nature of the cytoskeletal components. Microtubules are dynamic filaments with fundamental roles in eukaryotic cell organization and function. During cell division, they form the bipolar spindle, which segregates the chromosomes into the two daughter cells. Microtubules show prolonged states ...
The Importance of High Resolution Chromosome Analysis in the
... showed a subtle terminal deletion in the short arm of one chromosome 18 and the karyotype was re-designated as 46,XY,del(18)(p11.31) (Fig. 1). The referring clinicians were alerted immediately about the abnormality. This deletion was obvious in every metaphase spread with a banding resolution of ≥45 ...
... showed a subtle terminal deletion in the short arm of one chromosome 18 and the karyotype was re-designated as 46,XY,del(18)(p11.31) (Fig. 1). The referring clinicians were alerted immediately about the abnormality. This deletion was obvious in every metaphase spread with a banding resolution of ≥45 ...
Polo kinase and progression through M phase in Drosophila
... pointed to the possibility of reconciling the apparently disparate observations from Drosophila and budding yeast. Whether the MEN and SIN networks are truly replicated in metazoan cells is still by no means certain. However, as I will discuss below, a role for Polo in the late stages of mitosis was ...
... pointed to the possibility of reconciling the apparently disparate observations from Drosophila and budding yeast. Whether the MEN and SIN networks are truly replicated in metazoan cells is still by no means certain. However, as I will discuss below, a role for Polo in the late stages of mitosis was ...
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.