scholarly journals Rapid changes in tubulin RNA synthesis and stability induced by deflagellation in Chlamydomonas.

1984 ◽  
Vol 99 (6) ◽  
pp. 2074-2081 ◽  
Author(s):  
E J Baker ◽  
J A Schloss ◽  
J L Rosenbaum
Keyword(s):  
Rna Synthesis ◽  
Synthesis Rate ◽  
Beta Tubulin ◽  
Tubulin Genes ◽  
Induction Signal ◽  
Rapid Changes ◽  
Rapid Accumulation ◽  
Flagellar Regeneration ◽  
Flagellar Proteins ◽  
The Stability

Detachment of the flagella of Chlamydomonas induces a rapid accumulation of mRNAs for tubulin and other flagellar proteins. Measurement of the rate of alpha and beta tubulin RNA synthesis during flagellar regeneration shows that deflagellation elicits a rapid, 4-7-fold burst in tubulin RNA synthesis. The synthesis rate peaks within 10-15 min, then declines back to the predeflagellation rate. Redeflagellation of cells at times before the first flagellar regeneration is completed (and when cells have already accumulated elevated levels of tubulin RNA) induces another burst in tubulin RNA synthesis which is identical to the first in magnitude and duration. This finding indicates that the induction signal may act to simply reprogram the tubulin genes for a transient burst of maximal synthesis. Evidence is presented that the stability of the tubulin RNAs changes during regeneration. Stability changes include both an apparent stabilization during regeneration and accelerated decay following regeneration.

mRNA abundance changes during flagellar regeneration in Chlamydomonas reinhardtii

1984 ◽  
Vol 4 (3) ◽  
pp. 424-434
Author(s):  
J A Schloss ◽  
C D Silflow ◽  
J L Rosenbaum
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Control Cell ◽  
Beta Tubulin ◽  
Rna Sequences ◽  
Class V ◽  
Alpha Tubulin ◽  
Flagellar Regeneration ◽  
Flagellar Proteins ◽  
Kinetics Of ◽  
Class Iv

Flagellar amputation in Chlamydomonas reinhardtii induces the accumulation of a specific set of RNAs, many of which encode flagellar proteins. We prepared a cDNA clone bank from RNA isolated from cells undergoing flagellar regeneration. From this bank, we selected clones that contain RNA sequences that display several different patterns of abundance regulation. Based on quantitation of the relative amounts of labeled, cloned cDNAs hybridizing to dots of RNA on nitrocellulose filters, the cloned sequences were divided into five regulatory classes: class I RNAs remain at constant abundance during flagellar regeneration; classes II, III, and IV begin to increase in abundance within a few minutes after deflagellation, reach maximal abundance at successively later times during regeneration, and return to control cell levels within 2 to 3 h; and class V RNA abundance decreases during flagellar regeneration. Alpha- and beta-tubulin mRNAs are included in regulatory class IV. The abundance kinetics of alpha-tubulin mRNAs differ slightly from those of beta-tubulin mRNAs. The availability of these clones makes possible studies on the mechanisms controlling the abundance of a wide variety of different RNA species during flagellar regeneration in Chlamydomonas.

scholarly journals mRNA abundance changes during flagellar regeneration in Chlamydomonas reinhardtii.

1984 ◽  
Vol 4 (3) ◽  
pp. 424-434 ◽  
Author(s):  
J A Schloss ◽  
C D Silflow ◽  
J L Rosenbaum
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Control Cell ◽  
Beta Tubulin ◽  
Rna Sequences ◽  
Class V ◽  
Alpha Tubulin ◽  
Flagellar Regeneration ◽  
Flagellar Proteins ◽  
Kinetics Of ◽  
Class Iv

Flagellar amputation in Chlamydomonas reinhardtii induces the accumulation of a specific set of RNAs, many of which encode flagellar proteins. We prepared a cDNA clone bank from RNA isolated from cells undergoing flagellar regeneration. From this bank, we selected clones that contain RNA sequences that display several different patterns of abundance regulation. Based on quantitation of the relative amounts of labeled, cloned cDNAs hybridizing to dots of RNA on nitrocellulose filters, the cloned sequences were divided into five regulatory classes: class I RNAs remain at constant abundance during flagellar regeneration; classes II, III, and IV begin to increase in abundance within a few minutes after deflagellation, reach maximal abundance at successively later times during regeneration, and return to control cell levels within 2 to 3 h; and class V RNA abundance decreases during flagellar regeneration. Alpha- and beta-tubulin mRNAs are included in regulatory class IV. The abundance kinetics of alpha-tubulin mRNAs differ slightly from those of beta-tubulin mRNAs. The availability of these clones makes possible studies on the mechanisms controlling the abundance of a wide variety of different RNA species during flagellar regeneration in Chlamydomonas.

Tandem arrangement of tubulin genes in the protozoan parasite Leishmania enriettii

1983 ◽  
Vol 3 (6) ◽  
pp. 1070-1076
Author(s):  
S M Landfear ◽  
D McMahon-Pratt ◽  
D F Wirth
Keyword(s):  
Tandem Repeat ◽  
Blot Hybridization ◽  
Protozoan Parasite ◽  
Southern Blot Hybridization ◽  
Beta Tubulin ◽  
Developmentally Regulated ◽  
Alpha Tubulin ◽  
Tubulin Genes ◽  
Southern Blot Hybridization Analysis ◽  
Leishmania Enriettii

The arrangement of developmentally regulated alpha- and beta-tubulin genes has been studied in the parasitic protozoan Leishmania enriettii by using Southern blot hybridization analysis. The alpha-tubulin genes occur in a tandem repeat whose monomeric unit may be represented by a 2-kilobase PstI fragment. Similarly, the beta-tubulin genes probably occur in a separate tandem repeat consisting of approximately 4-kilobase units unlinked to the alpha-tubulin repeats.

Protein synthesis is required for rapid degradation of tubulin mRNA and other deflagellation-induced RNAs in Chlamydomonas reinhardi

1986 ◽  
Vol 6 (1) ◽  
pp. 54-61
Author(s):  
E J Baker ◽  
L R Keller ◽  
J A Schloss ◽  
J L Rosenbaum
Keyword(s):  
Protein Synthesis ◽  
Transcriptional Control ◽  
Protein S ◽  
Protein Synthesis Inhibitors ◽  
Control Factors ◽  
Flagellar Proteins ◽  
The Stability ◽  
And Control

After flagellar detachment in Chlamydomonas reinhardi, there is a rapid synthesis and accumulation of mRNAs for tubulin and other flagellar proteins. Maximum levels of these mRNAs (flagellar RNAs) are reached within 1 h after deflagellation, after which they are rapidly degraded to their predeflagellation levels. The degradation of alpha- and beta-tubulin RNAs was shown to be due to the shortening of their half-lives after accumulation (Baker et al., J. Cell Biol. 99:2074-2081, 1984). Deflagellation in the presence of protein synthesis inhibitors results in the accumulation of tubulin and other flagellar mRNAs by kinetics similar to those of controls. However, unlike controls, in which the accumulated mRNAs are rapidly degraded, these mRNAs are stabilized in cycloheximide. The stabilization by cycloheximide is specific for the flagellar mRNAs accumulated after deflagellation, since there is no change in the levels of flagellar mRNAs in nondeflagellated (uninduced) cells in the presence of cycloheximide. The kinetics of flagellar mRNA synthesis after deflagellation are shown to be the same in cycloheximide-treated and control cells by in vivo labeling and in vitro nuclear runoff experiments. These results show that protein synthesis is not required for the induced synthesis of flagellar mRNAs, and that all necessary transcriptional control factors are present in the cell before deflagellation, but that protein synthesis is required for the accelerated degradation of the accumulated flagellar mRNAs. Since cycloheximide prevents the induced synthesis and accumulation of flagellar proteins, it is possible that the product(s) of protein synthesis required for the accelerated decay of these mRNAs is a flagellar protein(s). The possibility that one or more flagellar proteins autoregulate the stability of the flagellar mRNAs is discussed.

scholarly journals Tandem arrangement of tubulin genes in the protozoan parasite Leishmania enriettii.

1983 ◽  
Vol 3 (6) ◽  
pp. 1070-1076 ◽  
Author(s):  
S M Landfear ◽  
D McMahon-Pratt ◽  
D F Wirth
Keyword(s):  
Tandem Repeat ◽  
Blot Hybridization ◽  
Protozoan Parasite ◽  
Southern Blot Hybridization ◽  
Beta Tubulin ◽  
Developmentally Regulated ◽  
Alpha Tubulin ◽  
Tubulin Genes ◽  
Southern Blot Hybridization Analysis ◽  
Leishmania Enriettii

The arrangement of developmentally regulated alpha- and beta-tubulin genes has been studied in the parasitic protozoan Leishmania enriettii by using Southern blot hybridization analysis. The alpha-tubulin genes occur in a tandem repeat whose monomeric unit may be represented by a 2-kilobase PstI fragment. Similarly, the beta-tubulin genes probably occur in a separate tandem repeat consisting of approximately 4-kilobase units unlinked to the alpha-tubulin repeats.

Identification of two human beta-tubulin isotypes

1983 ◽  
Vol 3 (5) ◽  
pp. 854-862
Author(s):  
J L Hall ◽  
L Dudley ◽  
P R Dobner ◽  
S A Lewis ◽  
N J Cowan
Keyword(s):  
Cdna Clone ◽  
Hela Cells ◽  
Untranslated Region ◽  
Genomic Sequence ◽  
Beta Tubulin ◽  
Tubulin Isotypes ◽  
Tubulin Genes ◽  
Processed Pseudogene ◽  
Carboxy Terminal ◽  
High Degree

The sequence of a human beta-tubulin cDNA clone (D beta-1) is described; our data revealed 95.6% homology compared with the sequence of a human beta-tubulin processed pseudogene derived by reverse transcription of a processed mRNA (Wilde et al., Nature [London] 297:83-84, 1982). However, the amino acid sequence encoded by this cDNA showed less homology with pig and chicken beta-tubulin sequences than the latter did to each other, with major divergence within the 15 carboxy-terminal amino acids. On the other hand, an independently isolated, functionally expressed genomic human beta-tubulin sequence (5 beta) possessed a very high degree of homology with chicken and pig beta-tubulins in this region. Thus, human cells appear to contain two distinct beta-tubulin isotypes. Both the intact beta-tubulin cDNA clone and a subclone containing only the 3' untranslated region detected two mRNA species in HeLa cells; these mRNAs were 1.8 and 2.6 kilobases long and were present in about equal amounts. Two independently subcloned probes constructed from the 3' untranslated region of the 5 beta genomic sequence also detected a 2.6-kilobase beta-tubulin mRNA. However, the 3'-untranslated-region probes from the cDNA clone and the genomic sequence did not cross-hybridize. Thus, at least two human beta-tubulin genes, each specifying a distinct isotype, are expressed in HeLa cells, and the 2.6-kilobase mRNA band is a composite of at least two comigrating beta-tubulin mRNAs.

Phenotypic consequences of tubulin overproduction in Saccharomyces cerevisiae: differences between alpha-tubulin and beta-tubulin

1990 ◽  
Vol 10 (10) ◽  
pp. 5295-5304
Author(s):  
B Weinstein ◽  
F Solomon
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Division ◽  
Microtubule Assembly ◽  
Beta Tubulin ◽  
Alpha Tubulin ◽  
Tubulin Genes ◽  
Data Support ◽  
Cell Biol

Overexpression of alpha- and beta-tubulin genes in Saccharomyces cerevisiae, separately or together, leads to accumulation of large excesses of each of the polypeptides and arrest of cell division. However, other consequences of overexpression of these genes differ in several ways. As shown previously (D. Burke, P. Gasdaska, and L. Hartwell, Mol. Cell. Biol. 9:1049-1059, 1989), overexpression of beta-tubulin leads, at early times, to loss of microtubule structures and loss of viability. Eventually, the excess beta-tubulin forms abnormal structures. We show here that, in contrast, overexpression of alpha-tubulin led to none of these phenotypes and in fact could suppress each of the phenotypes associated with beta-tubulin accumulation. Truncated forms of beta-tubulin that were not competent to carry out microtubule functions also failed to elicit the beta-tubulin-specific phenotypes when overexpressed. The data support the hypothesis that beta-tubulin in excess over alpha-tubulin is uniquely toxic, perhaps because it interferes with normal microtubule assembly.

Expression of alpha- and beta-Tubulin Genes during Growth of Trypanosoma cruzi Epimastigotes

1999 ◽  
Vol 18 (6) ◽  
pp. 449-455 ◽  
Author(s):  
Maria J. Gonzalez-Pino ◽  
Rafael Rangel-Aldao ◽  
Thelma C. Slezynger
Keyword(s):  
Trypanosoma Cruzi ◽  
Beta Tubulin ◽  
Tubulin Genes

scholarly journals Uncoupling of Chlamydomonas flagellar gene expression and outgrowth from flagellar excision by manipulation of Ca2+.

1991 ◽  
Vol 115 (6) ◽  
pp. 1651-1659 ◽  
Author(s):  
J L Cheshire ◽  
L R Keller
Keyword(s):  
Gene Expression ◽  
Mrna Abundance ◽  
Flagellar Gene ◽  
Wild Type ◽  
S1 Nuclease ◽  
Genes Encoding ◽  
Tightly Coupled ◽  
Flagellar Regeneration ◽  
Flagellar Proteins ◽  
Mechanical Shearing

Chlamydomonas cells respond to certain environmental stimuli by shedding their flagella. Flagellar loss induces a rapid, transient increase in expression of a specific set of genes encoding flagellar proteins, and assembly of a new flagellar pair. While flagellar gene expression and initiation of flagellar outgrowth are normally tightly coupled to flagellar excision, our results demonstrate that these processes can be uncoupled by manipulating Ca2+ levels or calmodulin activity. In our experiments, wild-type cells were stimulated to excise their flagella using mechanical shearing, and at times after deflagellation, flagellar lengths were measured and flagellar mRNA abundance changes were determined by S1 nuclease protection analysis. When extracellular Ca2+ was lowered by addition of EGTA to cultures before excision, flagellar mRNA abundance changes and flagellar outgrowth were temporally uncoupled from flagellar excision. When extracellular Ca2+ was lowered immediately after excision or when calmodulin activity was inhibited with W-7, flagellar outgrowth was uncoupled from flagellar excision and flagellar mRNA abundance changes. Whenever events in the process of flagellar regeneration were temporally uncoupled, the magnitude of the flagellar mRNA abundance change was reduced. These results suggest that flagellar gene expression may be regulated by multiple signals generated from these events, and implicate Ca2+ as a factor in the mechanisms controlling flagellar regeneration.

scholarly journals The two alpha-tubulin genes of Chlamydomonas reinhardi code for slightly different proteins.

1985 ◽  
Vol 5 (9) ◽  
pp. 2389-2398 ◽  
Author(s):  
C D Silflow ◽  
R L Chisholm ◽  
T W Conner ◽  
L P Ranum
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequences ◽  
Cdna Clones ◽  
Gene Products ◽  
Beta Tubulin ◽  
Alpha Tubulin ◽  
Tubulin Genes ◽  
Total Complement ◽  
Cloned Gene ◽  
Net Charges

Full-length cDNA clones corresponding to the transcripts of the two alpha-tubulin genes in Chlamydomonas reinhardi were isolated. DNA sequence analysis of the cDNA clones and cloned gene fragments showed that each gene contains 1,356 base pairs of coding sequence, predicting alpha-tubulin products of 451 amino acids. Of the 27 nucleotide differences between the two genes, only two result in predicted amino acid differences between the two gene products. In the more divergent alpha 2 gene, a leucine replaces an arginine at amino acid 308, and a valine replaces a glycine at amino acid 366. The results predicted that two alpha-tubulin proteins with different net charges are produced as primary gene products. The predicted amino acid sequences are 86 and 70% homologous with alpha-tubulins from rat brain and Schizosaccharomyces pombe, respectively. Each gene had two intervening sequences, located at identical positions. Portions of an intervening sequence highly conserved between the two beta-tubulin genes are also found in the second intervening sequence of each of the alpha genes. These results, together with our earlier report of the beta-tubulin sequences in C. reinhardi, present a picture of the total complement of genetic information for tubulin in this organism.

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