Tubulin Isotypes and the Multigene Tubulin Families

Cowan, Nicholas J.; Dudley, L

doi:10.1016/s0074-7696(08)62372-4

Cited by 60 publications

(18 citation statements)

References 41 publications

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“…The high level of sequence conservation within the coding regions of ␤-tubulin genes suggested that isotype-specific oligonucleotide primers should be designed within the nonconserved UTR of these genes (19). In view of the proximity of the gene sequence encoding a domain of the taxol-binding site (amino acids 1-31) to the 5Ј-UTR, isotype-specific primer pairs were therefore designed, where possible, so that the forward primer bound to the 5Ј-UTR of the relevant isotype and the reverse primer bound 3Ј to the taxol-binding region (Table I).…”

Section: Rna-pcr Analysis Of Expression Of Individual ␤-Tubulin Isotymentioning

confidence: 99%

“…2 Having confirmed the isotype specificity of each of the ␤-tubulin primer pairs, expression of each isotype was determined in the J774.2 cell line and in each of the drug-resistant sublines. Since the tubulin multigene family is known to include a number of genomic, intronless, nonfunctional pseudogenes (19), complete absence of genomic DNA in the cDNA samples 2 S. Lewis, personal communication. …”

Section: Rna-pcr Analysis Of Expression Of Individual ␤-Tubulin Isotymentioning

confidence: 99%

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Altered Expression of Mβ2, the Class II β-Tubulin Isotype, in a Murine J774.2 Cell Line with a High Level of Taxol Resistance

Haber

Burkhart

Regl

et al. 1995

Journal of Biological Chemistry

132

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A series of taxol-and taxotere-resistant J774.2 cell lines has been characterized with respect to altered expression of ␤-tubulin, the cellular target for these drugs. Vertebrates have six classes of ␤-tubulin isotypes, each displaying a distinct pattern of expression. Although the functional significance of multiple ␤-tubulins has not been fully defined, there is evidence that the individual isotypes contribute to differences in microtubule dynamics and drug binding. To determine if alterations in the expression of ␤-tubulin isotypes play a role in taxol resistance, a PCR-based methodology was developed that permits highly specific amplification of each of the six known murine ␤-tubulin isotypes. Two isotypes, M␤5 and M␤3, were expressed abundantly in the drug-sensitive parental J774.2 cells. Although expressed at an extremely low level in the parental cells, expression of the M␤2 isotype was increased 21-fold (<0.005) in the cell line most resistant to taxol. These findings suggest that a cell can alter its relative tubulin isotype composition in response to an external stress and specifically imply that altered expression of M␤2, the class II ␤-tubulin isotype, may contribute to the development of high resistance to taxol.

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Section: Rna-pcr Analysis Of Expression Of Individual ␤-Tubulin Isotymentioning

confidence: 99%

Section: Rna-pcr Analysis Of Expression Of Individual ␤-Tubulin Isotymentioning

confidence: 99%

Altered Expression of Mβ2, the Class II β-Tubulin Isotype, in a Murine J774.2 Cell Line with a High Level of Taxol Resistance

Haber

Burkhart

Regl

et al. 1995

Journal of Biological Chemistry

132

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“…To date, mutations or changes in the expression of ␤ -tubulin in human tumor cells have been poorly defined. One of the difficulties encountered in the study of tubulin in human taxol-resistant cells is the presence of multiple tubulin isotypes that are encoded by a large multigene family consisting of both functional and nonfunctional genes (11,12). The greatest diversity between the ␤ -tubulin isotypes occurs in the carboxy-terminal variable region sequence and to a lesser extent in the amino-terminal variable domain.…”

Section: Introductionmentioning

confidence: 99%

Taxol-resistant epithelial ovarian tumors are associated with altered expression of specific beta-tubulin isotypes.

Kavallaris¹,

Kuo²,

Burkhart³

et al. 1997

J. Clin. Invest.

546

484

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The treatment of advanced ovarian cancer with taxol is hindered by the development of drug resistance. The cellular target for taxol is the microtubule that is stabilized by the drug. Taxol preferentially binds to the ␤ subunit of tubulin of which there are six distinct isotypes in mammalian cells. We have used highly specific oligonucleotides and polymerase chain reaction to analyze expression of all six ␤ -tubulin genes. Human lung cancer cells (A549) were selected in 12 and 24 nM taxol resulting in cell lines that were 9-and 17-fold resistant, respectively. These cells displayed an altered ratio of classes I, II, III, and IVa ␤ -tubulin isotypes. Ovarian tumors, seven untreated primary and four taxolresistant tumor-bearing ascites, displayed significant increases ( P Ͻ 0.005) in classes I (3.6-fold), III (4.4-fold), and IVa (7.6-fold) isotypes in the taxol-resistant samples as compared with untreated primary ovarian tumors. The increased expression appears to be related to the resistance phenotype, as the basal levels of the class III and IVa isotypes in the untreated tumors were extremely low. This is the first report of altered expression of specific ␤ -tubulin genes in taxol-resistant ovarian tumors and we propose that the latter may play a role in clinical resistance to taxol. ( J.

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“…Differences in tubulin proteins suggest the existence of different tubulin genes. Indeed, most eukaryotes, including the trypanosomatid protozoa, have multiple genes encoding for tubulin (13,14). The a-and j-tubulin genes of T. brucei are tandemly duplicated (15,16), whereas those of Leishmania enriettii are in separate a and f3 clusters (17).…”

mentioning

confidence: 99%

Differential expression of mRNAs for alpha- and beta-tubulin during differentiation of the parasitic protozoan Leishmania mexicana.

Fong¹,

Wallach²,

Keithly³

et al. 1984

Proc. Natl. Acad. Sci. U.S.A.

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The parasitic protozoan Leishmania mexicana amazonensis has two developmental stages: a motile flagellated promastigote stage and a sessile intracellular amastigote stage. In our previous work, cells of the promastigote stage were found to synthesize more tubulin protein than those of the amastigote stage. Here, tubulin mRNAs in these leishmanias were analyzed. Based on dot blot hybridization between total leishmanial RNA and tubulin-specific cDNA probes derived from chicken brain, amastigotes and promastigotes were found to have approximately equal amounts of alpha- and beta-tubulin mRNAs. RNA blotting of leishmanial RNA, using chicken tubulin cDNA probes, showed that amastigotes and promastigotes both gave a single mRNA species of 2100 nucleotides for alpha-tubulin in roughly similar quantities. However, such analysis for beta-tubulin revealed mainly a single mRNA species of 3600 nucleotides for amastigotes and three species of 2800, 3600, and 4400 nucleotides for promastigotes, the smallest mRNA being the most predominant. Thus, regulation of gene expression appears to be different only for beta-tubulin between the two developmental stages of this protozoan.

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Tubulin Isotypes and the Multigene Tubulin Families

Cited by 60 publications

References 41 publications

Altered Expression of Mβ2, the Class II β-Tubulin Isotype, in a Murine J774.2 Cell Line with a High Level of Taxol Resistance

Altered Expression of Mβ2, the Class II β-Tubulin Isotype, in a Murine J774.2 Cell Line with a High Level of Taxol Resistance

Taxol-resistant epithelial ovarian tumors are associated with altered expression of specific beta-tubulin isotypes.

Differential expression of mRNAs for alpha- and beta-tubulin during differentiation of the parasitic protozoan Leishmania mexicana.

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