The plant cytoskeleton - The Company of Biologists
... ing cytokinesis, at the nucleus or at the cell cortex? Are the nucleation sites different from those involved in mitosis and cytokinesis; if not, do the sites migrate from the peri-nuclear region to the cortex in order to initiate the new array? In files of cells, new arrays can be regenerated trans ...
... ing cytokinesis, at the nucleus or at the cell cortex? Are the nucleation sites different from those involved in mitosis and cytokinesis; if not, do the sites migrate from the peri-nuclear region to the cortex in order to initiate the new array? In files of cells, new arrays can be regenerated trans ...
mutant alleles of polymitotic that disrupt the cell cycle
... stages of meiosis II. The po meiocyte cells undergo a normal anaphase II and telophase II as shown by the presence of apparently normal spindles and phragmoplasts (data not shown). However, even within one tetrad, asynchronous cell divisions are observed in late stages of meiosis II (Fig. 2A and B). ...
... stages of meiosis II. The po meiocyte cells undergo a normal anaphase II and telophase II as shown by the presence of apparently normal spindles and phragmoplasts (data not shown). However, even within one tetrad, asynchronous cell divisions are observed in late stages of meiosis II (Fig. 2A and B). ...
A Late Mitotic Regulatory Network Controlling
... of mitotic cyclins, the APC also catalyzes the ubiquitination of other mitotic regulatory proteins. APC-dependent degradation of the Pds1 protein of S. cerevisiae (or Cut2 of Schizosaccharomyces pombe) is required for progression from metaphase to anaphase (Cohen-Fix et al., 1996; Funabiki et al., 1 ...
... of mitotic cyclins, the APC also catalyzes the ubiquitination of other mitotic regulatory proteins. APC-dependent degradation of the Pds1 protein of S. cerevisiae (or Cut2 of Schizosaccharomyces pombe) is required for progression from metaphase to anaphase (Cohen-Fix et al., 1996; Funabiki et al., 1 ...
as a PDF
... for septation) in the control of septum formation in A. nidulans. The kfsA deletion caused an increase in the number of conidiophores with septa in their stalks from 20% in wild type to 60% in the mutant strain. Interestingly, 7% of metulae contained two nuclei and the corresponding phialides remain ...
... for septation) in the control of septum formation in A. nidulans. The kfsA deletion caused an increase in the number of conidiophores with septa in their stalks from 20% in wild type to 60% in the mutant strain. Interestingly, 7% of metulae contained two nuclei and the corresponding phialides remain ...
A low resolution structure of a component of the Cytokine responsive
... IKKgamma, leading to activation of the IKK complex. To date, there has been no experimentally-derived high or low-resolution structural information on the IKK complex or any of its components presented in the literature. Here we present for the first time structural information on the isolated recom ...
... IKKgamma, leading to activation of the IKK complex. To date, there has been no experimentally-derived high or low-resolution structural information on the IKK complex or any of its components presented in the literature. Here we present for the first time structural information on the isolated recom ...
Prentice Hall Biology
... Proteins that respond to events outside the cell are called external regulators. External regulators direct cells to speed up or slow down the cell cycle. ...
... Proteins that respond to events outside the cell are called external regulators. External regulators direct cells to speed up or slow down the cell cycle. ...
Dominant-lethal alpha-tubulin mutants defective in microtubule depolymerization in yeast.
... Monitoring Editor: J. Richard McIntosh ...
... Monitoring Editor: J. Richard McIntosh ...
10.2 pp (Biology 2015-16)
... separate to become individual chromosomes. The chromosomes separate into two groups near the poles of the ...
... separate to become individual chromosomes. The chromosomes separate into two groups near the poles of the ...
ROLE OF SPINDLE MICROTUBULES IN THE
... 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 delayed? (c) Cleavage: Does the egg cortex remain ...
... 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 delayed? (c) Cleavage: Does the egg cortex remain ...
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 ...
Non-specific (entropic) forces as major determinants of the structure
... and β-sheets that are used to build proteins. They also understand the principles that drive folding into tertiary structures (e.g., by positioning hydrophobic residues in the interior), and assembly into quaternary complexes (e.g., through interactions between complementary surfaces). They expect t ...
... and β-sheets that are used to build proteins. They also understand the principles that drive folding into tertiary structures (e.g., by positioning hydrophobic residues in the interior), and assembly into quaternary complexes (e.g., through interactions between complementary surfaces). They expect t ...
Actin in plants
... appears (although it is not proven) that the phragmoplast arises out of the post-anaphase spindle. As the double ring of phragmoplast microtubules expands outwards, actin filaments can clearly be seen parallel to the tubules and are likely to function in cell plate deposition. Actin filaments amongs ...
... appears (although it is not proven) that the phragmoplast arises out of the post-anaphase spindle. As the double ring of phragmoplast microtubules expands outwards, actin filaments can clearly be seen parallel to the tubules and are likely to function in cell plate deposition. Actin filaments amongs ...
Microtubule
... A defining characteristic of living organisms is their ability to proliferate and the very fundamental basis is the division of a single cell into two daughter cells with exact complements of the parental genetic material. (Figure 3) At the beginning of the early prophase of the cell cycle, centroso ...
... A defining characteristic of living organisms is their ability to proliferate and the very fundamental basis is the division of a single cell into two daughter cells with exact complements of the parental genetic material. (Figure 3) At the beginning of the early prophase of the cell cycle, centroso ...
10.2 Process of Cell Division
... separate to become individual chromosomes. The chromosomes separate into two groups near the poles of the ...
... separate to become individual chromosomes. The chromosomes separate into two groups near the poles of the ...
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 ...
Cleavage furrow formation and ingression during animal cytokinesis
... case. For example, in embryos that have mutant air-2, zen-4 and spd-1 genes, which respectively encode a kinase, a kinesin and a microtubule-binding protein required for cytokinesis (see below and Table 1), the spindle length is increased, but only a single furrow forms and does so at the proper loc ...
... case. For example, in embryos that have mutant air-2, zen-4 and spd-1 genes, which respectively encode a kinase, a kinesin and a microtubule-binding protein required for cytokinesis (see below and Table 1), the spindle length is increased, but only a single furrow forms and does so at the proper loc ...
Building and Breaking Bridges between Sister Chromatids
... resulting tension is thought to stabilize kinetochore-microtubule attachments, which are otherwise highly labile. Very little is known about the mechanism by which microtubules attach and detach from kinetochores. It is nevertheless clear that sister chromatid cohesion must have a key role in genera ...
... resulting tension is thought to stabilize kinetochore-microtubule attachments, which are otherwise highly labile. Very little is known about the mechanism by which microtubules attach and detach from kinetochores. It is nevertheless clear that sister chromatid cohesion must have a key role in genera ...
Plant RanGAPs are localized at the nuclear envelope in interphase
... proteins, and importin b which forms the active import complex in the cytosol together with RanGDP, importin a and the bound cargo protein (Smith and Raikhel, 1999). A gene encoding the export receptor XPO1 (Haasen et al., 2000), which recognizes nuclear export signals on the cargo protein and forms ...
... proteins, and importin b which forms the active import complex in the cytosol together with RanGDP, importin a and the bound cargo protein (Smith and Raikhel, 1999). A gene encoding the export receptor XPO1 (Haasen et al., 2000), which recognizes nuclear export signals on the cargo protein and forms ...
+TIPs and Microtubule Regulation. The Beginning of the Plus End in
... inherent dynamics of the tubule and by an array of regulatory proteins termed MAPs (MT-associated proteins). The inherent dynamics, or dynamic instability, of MTs is governed by their ends, which exhibit rapid transitions between growing and shrinking states (Desai and Mitchison, 1997). The minus en ...
... inherent dynamics of the tubule and by an array of regulatory proteins termed MAPs (MT-associated proteins). The inherent dynamics, or dynamic instability, of MTs is governed by their ends, which exhibit rapid transitions between growing and shrinking states (Desai and Mitchison, 1997). The minus en ...
central spindle and contractile ring for cytokinesis encodes a kinesin
... 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 spindle and the cell cortex and are necessary for completion of cytokinesis (Eckley et al. 1997; Earnshaw and ...
... 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 spindle and the cell cortex and are necessary for completion of cytokinesis (Eckley et al. 1997; Earnshaw and ...
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 ...
The role of structural disorder in cell cycle regulation, related clinical
... the recruitment of Bub1 and BubR1 to Knl1 [46]. Through binding with Bub1, Knl1 indirectly mediates the recruitment of PP2A, which is important for stabilizing kinetochoremicrotubule binding [47]. Another interaction motif, MELT is found in the N-terminal and middle regions of Knl1 [39], in varying ...
... the recruitment of Bub1 and BubR1 to Knl1 [46]. Through binding with Bub1, Knl1 indirectly mediates the recruitment of PP2A, which is important for stabilizing kinetochoremicrotubule binding [47]. Another interaction motif, MELT is found in the N-terminal and middle regions of Knl1 [39], in varying ...
Barbara McClintock - Nobel Lecture
... the fragment could be a ring-chromosome, and that losses of the fragment were caused by an exchange between sister chromatids following replication of the ring. This would produce a double-size ring with two centromeres. In the following anaphase, passage of the centromeres to opposite poles would p ...
... the fragment could be a ring-chromosome, and that losses of the fragment were caused by an exchange between sister chromatids following replication of the ring. This would produce a double-size ring with two centromeres. In the following anaphase, passage of the centromeres to opposite poles would p ...
File
... – Microtubules are hollow, cylindrical structures. – The microtubule is a set of globular proteins arranged in longitudinal rows called protofilaments. – Microtubules contain 13 protofilaments. – Each protofilament is assembled from dimers of α- and ß-tubulin subunits assembled into tubules with plu ...
... – Microtubules are hollow, cylindrical structures. – The microtubule is a set of globular proteins arranged in longitudinal rows called protofilaments. – Microtubules contain 13 protofilaments. – Each protofilament is assembled from dimers of α- and ß-tubulin subunits assembled into tubules with plu ...
Alight-inducible organelle targeting system for dynamically
... localization and that the presence of the fusion protein did not alter cell doubling time. Following these assays, nine PhyB-mCherry-anchor fusions targeting eight different locations displayed good behavior (Figure 1C), and the other 11 strains were eliminated because of growth defects or failure o ...
... localization and that the presence of the fusion protein did not alter cell doubling time. Following these assays, nine PhyB-mCherry-anchor fusions targeting eight different locations displayed good behavior (Figure 1C), and the other 11 strains were eliminated because of growth defects or failure o ...
Spindle checkpoint
During the process of cell division, the spindle checkpoint prevents separation of the duplicated chromosomes until each chromosome is properly attached to the spindle apparatus. In order to preserve the cell's identity and proper function, it is necessary to maintain the appropriate number of chromosomes after each cell division. An error in generating daughter cells with fewer or greater number of chromosomes than expected (a situation termed aneuploidy), may lead in best case to cell death, or alternatively it may generate catastrophic phenotypic results. Examples include: In cancer cells, aneuploidy is a frequent event, indicating that these cells present a defect in the machinery involved in chromosome segregation, as well as in the mechanism ensuring that segregation is correctly performed. In humans, Down syndrome appears in children carrying in their cells one extra copy of chromosome 21, as a result of a defect in chromosome segregation during meiosis in one of the progenitors. This defect will generate a gamete (spermatozoide or oocyte) with an extra chromosome 21. After fecundation, this gamete will generate an embryo with three copies of chromosome 21.The mechanisms verifying that all the requirements to pass to the next phase in the cell cycle have been fulfilled are called checkpoints. All along the cell cycle, there are different checkpoints. The checkpoint ensuring that chromosome segregation is correct is termed spindle assembly checkpoint (SAC), spindle checkpoint or mitotic checkpoint. During mitosis or meiosis, the spindle checkpoint prevents anaphase onset until all chromosomes are properly attached to the spindle. To achieve proper segregation, the two kinetochores on the sister chromatids must be attached to opposite spindle poles (bipolar orientation). Only this pattern of attachment will ensure that each daughter cell receives one copy of the chromosome.