scholarly journals Distinct localization and cell cycle dependence of COOH terminally tyrosinolated alpha-tubulin in the microtubules of Trypanosoma brucei brucei.

1987 ◽  
Vol 104 (3) ◽  
pp. 439-446 ◽  
Author(s):  
T Sherwin ◽  
A Schneider ◽  
R Sasse ◽  
T Seebeck ◽  
K Gull
Keyword(s):  
Cell Cycle ◽  
Trypanosoma Brucei ◽  
Temporal Modulation ◽  
Trypanosoma Brucei Brucei ◽  
Alpha Tubulin ◽  
Tubulin Isoforms ◽  
A Cell ◽  
Cell Cycle Dependence ◽  
Microtubular Structures ◽  
Cycle Dependence

alpha-Tubulin can be posttranslationally modified in that its COOH-terminal amino acid residue, tyrosine, can be selectively removed and replaced again. This reaction cycle involves two enzymes, tubulin carboxypeptidase and tubulin tyrosine ligase. The functional significance of this unusual modification is unclear. The present study demonstrates that posttranslational tyrosinolation of alpha-tubulin does occur in the parasitic hemoflagellate Trypanosoma brucei brucei and that posttranslational tyrosinolation can be detected in both alpha-tubulin isoforms found in this organism. Trypanosomes contain a number of microtubular structures: the flagellar axoneme; the subpellicular layer of singlet microtubules which are closely associated with the cell membrane; the basal bodies; and a cytoplasmic pool of soluble tubulin. Tyrosinolated alpha-tubulin is present in all these populations. However, immunofluorescence studies demonstrate a distinct localization of tyrosinolated alpha-tubulin within individual microtubules and organelles. This localization is subject to a temporal modulation that correlates strongly with progress of a cell through the cell cycle. Our results indicate that the presence of tyrosinolated alpha-tubulin is a marker for newly formed microtubules.

scholarly journals A novel inward-rectifying K+ current with a cell-cycle dependence governs the resting potential of mammalian neuroblastoma cells.

1995 ◽  
Vol 489 (2) ◽  
pp. 455-471 ◽  
Author(s):  
A Arcangeli ◽  
L Bianchi ◽  
A Becchetti ◽  
L Faravelli ◽  
M Coronnello ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Neuroblastoma Cells ◽  
Resting Potential ◽  
K Current ◽  
A Cell ◽  
Cell Cycle Dependence ◽  
Cycle Dependence

Tubulin post-translational modifications and the construction of microtubular organelles in Trypanosoma brucei

1988 ◽  
Vol 90 (4) ◽  
pp. 577-589 ◽  
Author(s):  
R. Sasse ◽  
K. Gull
Keyword(s):  
Cell Cycle ◽  
Trypanosoma Brucei ◽  
Mitotic Spindle ◽  
Post Translational Modification ◽  
Post Translational Modifications ◽  
Alpha Tubulin ◽  
Daughter Cells ◽  
A Cell ◽  
Microtubular Organelles ◽  
Tubulin Content

We have used specific monoclonal antibodies to facilitate a study of acetylated and tyrosinated alpha-tubulin in the microtubule (MT) arrays in the Trypanosoma brucei cell. Acetylated alpha-tubulin is not solely located in the stable microtubular arrays but is present even in the ephemeral microtubules of the mitotic spindle. Moreover, there is a uniform distribution of this isoform in all arrays. Studies of flagella complexes show that acetylation is concomitant with assembly of MTs. There is no subsequent major modulation in the content of acetylated alpha-tubulin in MTs. Conversely, polymerizing flagellar MTs have a high tyrosinated alpha-tubulin content, which is subsequently reduced to a basal level at a discrete point in the cell cycle. The MTs of the intranuclear mitotic spindle appear never to contain tyrosinated alpha-tubulin, suggesting that they are actually constructed of detyrosinated alpha-tubulin or that detyrosination is extremely rapid at this time in the cell cycle. T. brucei therefore, represents a cell type with extremely active mechanisms for the post-translational modification of alpha-tubulin. Our analyses of the timing of acquisition and modulation in relation to MT construction in T. brucei, suggest that acetylation and detyrosination of alpha-tubulin are two independently regulated post-translational modifications, that are not uniquely associated with particular subsets of MTs of defined lability, position or function. Post-assembly detyrosination of alpha-tubulin may provide a mechanism whereby the cell could discriminate between new and old MTs, during construction of the cytoskeleton through the cell cycle. However, we also suggest that continuation of detyrosination, allows the cell, at cell division, to partition into daughter cells two equivalent sets of cytoskeletal MTs.

scholarly journals Subpellicular and flagellar microtubules of Trypanosoma brucei brucei contain the same alpha-tubulin isoforms.

1987 ◽  
Vol 104 (3) ◽  
pp. 431-438 ◽  
Author(s):  
A Schneider ◽  
T Sherwin ◽  
R Sasse ◽  
D G Russell ◽  
K Gull ◽  
...  
Keyword(s):  
Trypanosoma Brucei ◽  
Close Contact ◽  
Electrophoretic Analysis ◽  
Translation Product ◽  
Trypanosoma Brucei Brucei ◽  
Alpha Tubulin ◽  
Predominant Species ◽  
Tubulin Isoforms ◽  
Small Pool ◽  
Flagellar Axoneme

The cytoskeleton of the parasitic hemoflagellate Trypanosoma brucei brucei essentially consists of two microtubule-based structures: a subpellicular layer of singlet microtubules, which are in close contact with the cell membrane, and the flagellar axoneme. In addition, the cells contain a small pool of soluble tubulin. Two-dimensional gel electrophoretic analysis of the tubulins present in these subcellular compartments revealed two distinct electrophoretic isoforms of alpha-tubulin, termed alpha 1 and alpha 3. alpha 1-Tubulin most likely represents the primary translation product, while alpha 3-tubulin is a posttranslationally acetylated derivative of alpha 1-tubulin. In the pool of soluble cytoplasmic tubulin, alpha 1 is the predominant species, while the very stable flagellar microtubules contain almost exclusively the alpha 3-tubulin isoform. The subpellicular microtubules contain both isoforms. Neither of the two alpha-tubulin isoforms is organelle specific, but the alpha 3 isoform is predominantly located in stable microtubules.

The Cell Cycle Dependence of Thermotolerance: II. CHO Cells Heated at 45.0°C

1984 ◽  
Vol 98 (3) ◽  
pp. 491 ◽  
Author(s):  
R. A. Read ◽  
M. H. Fox ◽  
J. S. Bedford
Keyword(s):  
Cell Cycle ◽  
Cho Cells ◽  
Cell Cycle Dependence ◽  
Cycle Dependence

scholarly journals Cell Cycle-Dependence of Autophagic Activity and Inhibition of Autophagosome Formation at M Phase in Tobacco BY-2 Cells

2020 ◽  
Vol 21 (23) ◽  
pp. 9166
Author(s):  
Shigeru Hanamata ◽  
Takamitsu Kurusu ◽  
Kazuyuki Kuchitsu
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Progression ◽  
Plant Cells ◽  
Regulatory Mechanisms ◽  
Cdk Inhibitor ◽  
Autophagosome Formation ◽  
Cycle Progression ◽  
M Phase ◽  
Cell Cycle Dependence ◽  
Cycle Dependence

Autophagy is ubiquitous in eukaryotic cells and plays an essential role in stress adaptation and development by recycling nutrients and maintaining cellular homeostasis. However, the dynamics and regulatory mechanisms of autophagosome formation during the cell cycle in plant cells remain poorly elucidated. We here analyzed the number of autophagosomes during cell cycle progression in synchronized tobacco BY-2 cells expressing YFP-NtATG8a as a marker for the autophagosomes. Autophagosomes were abundant in the G2 and G1 phases of interphase, though they were much less abundant in the M and S phases. Autophagosomes drastically decreased during the G2/M transition, and the CDK inhibitor roscovitine inhibited the G2/M transition and the decrease in autophagosomes. Autophagosomes were rapidly increased by a proteasome inhibitor, MG-132. MG-132-induced autophagosome formation was also markedly lower in the M phases than during interphase. These results indicate that the activity of autophagosome formation is differently regulated at each cell cycle stage, which is strongly suppressed during mitosis.

scholarly journals Cell Cycle Dependence of Group VIA Calcium-independent Phospholipase A2Activity

2004 ◽  
Vol 279 (51) ◽  
pp. 52881-52892 ◽  
Author(s):  
Alex D. Manguikian ◽  
Suzanne E. Barbour
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Dependence ◽  
Cycle Dependence
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