scholarly journals Acetylated alpha-tubulin in Physarum: immunological characterization of the isotype and its usage in particular microtubular organelles.

1987 ◽  
Vol 104 (1) ◽  
pp. 41-49 ◽  
Author(s):  
R Sasse ◽  
M C Glyn ◽  
C R Birkett ◽  
K Gull
Keyword(s):  
Monoclonal Antibody ◽  
Mitotic Spindle ◽  
Biochemical Characterization ◽  
Alpha Tubulin ◽  
Acetylated Tubulin ◽  
Tubulin Isotype ◽  
Cytoplasmic Microtubules ◽  
Spindle Microtubules ◽  
Microtubular Organelles

We have used monoclonal antibodies specific for acetylated and unacetylated alpha-tubulin to characterize the acetylated alpha-tubulin isotype of Physarum polycephalum, its expression in the life cycle, and its localization in particular microtubular organelles. We have used the monoclonal antibody 6-11B-1 (Piperno, G., and M. T. Fuller, 1985, J. Cell Biol., 101:2085-2094) as the probe for acetylated alpha-tubulin and have provided a biochemical characterization of the monoclonal antibody KMP-1 as a probe for unacetylated tubulin in Physarum. Concomitant use of these two probes has allowed us to characterize the acetylated alpha-tubulin of Physarum as the alpha 3 isotype. We have detected this acetylated alpha 3 tubulin isotype in both the flagellate and in the myxameba, but not in the plasmodium. In the flagellate, acetylated tubulin is present in both the flagellar axonemes and in an extensive array of cytoplasmic microtubules. The extensive arrangement of acetylated cytoplasmic microtubules and the flagellar axonemes are elaborated during the myxameba-flagellate transformation. In the myxameba, acetylated tubulin is not present in the cytoplasmic microtubules nor in the mitotic spindle microtubules, but is associated with the two centrioles of this cell. These findings, taken together with the apparent absence of acetylated alpha-tubulin in the ephemeral microtubules of the plasmodium suggest a natural correspondence between the presence of acetylated alpha-tubulin and microtubule organelles that are intrinsically stable or cross-linked.

scholarly journals Mitosis in the fission yeast Schizosaccharomyces pombe as revealed by freeze-substitution electron microscopy

1986 ◽  
Vol 80 (1) ◽  
pp. 253-268
Author(s):  
K. Tanaka ◽  
T. Kanbe
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Mitotic Spindle ◽  
Nuclear Division ◽  
Freeze Substitution ◽  
Spindle Pole ◽  
Nuclear Space ◽  
Spindle Pole Bodies ◽  
Transmission Electron ◽  
Cytoplasmic Microtubules ◽  
Spindle Microtubules

Nuclear division in Schizosaccharomyces pombe has been studied in transmission electron micrographs of sections of cells fixed by a method of freeze-substitution. We have found cytoplasmic microtubules in the vicinity of the spindle pole bodies and two kinds of microtubules, short discontinuous ones and long, parallel ones in the intranuclear mitotic spindle. For most of the time taken by nuclear division the spindle pole bodies face each other squarely across the nuclear space but early in mitosis they briefly appear twisted out of alignment with each other, thereby imparting a sigmoidal shape to the bundle of spindle microtubules extending between them. This configuration is interpreted as indicating active participation of the spindle in the initial elongation of the dividing nucleus. It is proposed that mitosis is accompanied by the shortening of chromosomal microtubules simultaneously with the elongation of the central pole-to-pole bundle of microtubules of the intranuclear spindle. Daughter nuclei are separated by the sliding apart of interdigitating microtubules of the spindle at telophase. Some of the latter bear dense knobs at their ends.

Biochemical Characterization of a Monoclonal Antibody to the H Type-2 Antigen: Comparison to Other ABH Antibodies

Hybridoma ◽  
1986 ◽  
Vol 5 (2) ◽  
pp. 117-127 ◽  
Author(s):  
BARNETT B. ROSENBLUM ◽  
W. JOHN JUDD ◽  
THOMAS E. CAREY
Keyword(s):  
Monoclonal Antibody ◽  
Biochemical Characterization

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.

Fine structure of an organelle associated with the nucleus and cytoplasmic microtubules in the cellular slime mould Polysphondylium violaceum

1975 ◽  
Vol 18 (2) ◽  
pp. 315-326
Author(s):  
U.P. Roos
Keyword(s):  
Mitotic Spindle ◽  
Spindle Pole ◽  
Interphase Nuclei ◽  
Spindle Pole Bodies ◽  
Nucleation Sites ◽  
Cellular Slime ◽  
Granular Matrix ◽  
Cytoplasmic Microtubules ◽  
Spindle Microtubules ◽  
Opaque Body

Polysphondylium violaceum was grown in association with Escherichia coli. Vegetative amoebae and pseudoplasmodia were fixed under different conditions and processed for electron microscopy. An electron-opaque body (nucleus-associated body, NAB) lies in the cytoplasm near the tapered end of interphase nuclei. The NAB consists of a disk-shaped, multilayered core, approximately 200 nm in diameter and 150 nm thick, embedded in a granular matrix from which electron-opaque nodules protrude. The nodules are termination points of microtubules radiating from the NAB into the cytoplasm or running along the nucleus. On the average there are 16 nodules per NAB. One or two microtubules terminate in each nodule. Spindle pole bodies, arising by duplication of the NAB at the beginning of mitosis, are unstructured foci for spindle microtubules in mitotic cells. It is suggested that cytoplasmic microtubules do not determine cell shape, but they probably cause the tapering deformation of the nucleus. They may, furthermore, represent a storage form of subunits for utilization during the formation of the mitotic spindle. The nodules of the NAB are potential nucleation sites of cytoplasmic microtubules during interphase. Spindle pole bodies presumably acquire a microtubule organizing capability by integration of the decondensed nodules.

Characterization of mid-spindle microtubules during furrow positioning in early cleavage period zebrafish embryos

Zygote ◽  
2004 ◽  
Vol 12 (3) ◽  
pp. 221-230 ◽  
Author(s):  
Karen W. Lee ◽  
Steven M. Ho ◽  
Carey H. Wong ◽  
Sarah E. Webb ◽  
Andrew L. Miller
Keyword(s):  
Mitotic Spindle ◽  
Positional Information ◽  
Zebrafish Embryos ◽  
Cleavage Furrow ◽  
Early Cleavage ◽  
Microtubule Array ◽  
Spindle Microtubules ◽  
Dynamic Population ◽  
Cortical Endoplasmic Reticulum

We report evidence to suggest that during the first few meroblastic cell divisions in zebrafish embryos a dynamic population of central-spindle microtubules serve a crucial function in positioning the cleavage furrow at the surface of the blastoderm. Originating from the mid-zone of the mitotic spindle they develop into what we term a mid-spindle ‘pre-furrowing microtubule array’ that expands upward and outward from the spindle mid-zone towards the blastodisc surface. We suggest that this structure transmits positional information to the blastodisc cortex that results in the correctly positioned assembly of the cytokinetic contractile apparatus. We also propose that the pre-furrowing microtubule array then develops into a furrow-ingression microtubule array that helps direct and assemble the deepening furrow as it cuts its way through the blastodisc. Due to the location of its origin, the pre-furrowing microtubule array serves to successfully separate the daughter nuclei and thus equally divide the blastoderm. Furthermore, co-localization with elements of the cortical endoplasmic reticulum and their inositol 1,4,5-trisphosphate receptors suggests that the pre-furrowing microtubule array may also play a role in organizing localized Ca2+ transients that have been shown to be essential to the furrow positioning, propagation and deepening process during cytokinesis in zebrafish embryos.

scholarly journals A rat monoclonal antibody reacting specifically with the tyrosylated form of alpha-tubulin. I. Biochemical characterization, effects on microtubule polymerization in vitro, and microtubule polymerization and organization in vivo.

1983 ◽  
Vol 97 (5) ◽  
pp. 1467-1475 ◽  
Author(s):  
J Wehland ◽  
M C Willingham ◽  
I V Sandoval
Keyword(s):  
Monoclonal Antibody ◽  
Biochemical Characterization ◽  
Mammalian Species ◽  
Antigenic Site ◽  
In Vivo Studies ◽  
Alpha Tubulin ◽  
3T3 Fibroblasts ◽  
Microtubule Polymerization

The antigenic site recognized by a rat monoclonal antibody (clone YL 1/2) reacting with alpha-tubulin (Kilmartin, J.V., B. Wright, and C. Milstein, 1982, J. Cell Biol., 93:576-582) has been determined and partially characterized. YL 1/2 reacts specifically with the tyrosylated form of brain alpha-tubulin from different mammalian species. YL 1/2 reacts with the synthetic peptide Gly-(Glu)3-Gly-(Glu)2-Tyr, corresponding to the carboxyterminal amino acid sequence of tyrosylated alpha-tubulin, but does not react with Gly-(Glu)3-Gly-(Glu)2, the constituent peptide of detyrosylated alpha-tubulin. Electron microscopy as well as direct and indirect immunofluorescence microscopy shows that YL 1/2 binds to the surface of microtubules polymerized in vitro and in vivo. Further in vitro studies show that the antibody has no effect on the rate and extent of microtubule polymerization, the stability of microtubules, and the incorporation of the microtubule-associated proteins (MAP2) and tau into microtubules. In vivo studies using Swiss 3T3 fibroblasts injected with YL 1/2 show that; when injected at low concentration (2 mg IgG/ml in the injection solution), the antibody binds to microtubules without changing their distribution in the cytoplasm. Injection of larger concentration of YL 1/2 (6 mg IgG/ml) induces the formation of microtubule bundles, and still higher concentrations cause the aggregation of microtubule bundles around the nucleus (greater than 12 mg IgG/ml).

Biochemical characterization of the monoclonal antibody-defined ovarian carcinoma-associated antigen SGA

1986 ◽  
Vol 37 (5) ◽  
pp. 705-712 ◽  
Author(s):  
Theonne A. de Kretser ◽  
Heather J. Thorne ◽  
Diana Picone ◽  
David G. Jose
Keyword(s):  
Monoclonal Antibody ◽  
Ovarian Carcinoma ◽  
Biochemical Characterization

scholarly journals Biochemical Characterization of Human Anti-Hepatitis B Monoclonal Antibody Produced in the Microalgae Phaeodactylum tricornutum

PLoS ONE ◽  
2015 ◽  
Vol 10 (10) ◽  
pp. e0139282 ◽  
Author(s):  
Gaëtan Vanier ◽  
Franziska Hempel ◽  
Philippe Chan ◽  
Michael Rodamer ◽  
David Vaudry ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Hepatitis B ◽  
Phaeodactylum Tricornutum ◽  
Biochemical Characterization
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