scholarly journals Primary myeloid cell proteomics and transcriptomics: importance of ß tubulin isotypes for osteoclast function

2019 ◽  
Author(s):  
David Guérit ◽  
Pauline Marie ◽  
Anne Morel ◽  
Justine Maurin ◽  
Christel Verollet ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Myeloid Cells ◽  
Zone Structure ◽  
Tubulin Isotypes ◽  
Immature Dendritic Cells ◽  
Tubulin Isotype ◽  
Gene And Protein Expression ◽  
Primary Mouse ◽  
Sealing Zone ◽  
Β Tubulin

AbstractAmong hematopoietic cells. osteoclasts (Oc) and immature dendritic cells (Dc) are closely related myeloid cells with distinct functions; Oc participate skeleton maintenance while Dc sample the environment for foreign antigens. Such specificities rely on profound modifications of gene and protein expression during Oc and Dc differentiation. We provide global proteomic and transcriptomic analyses of primary mouse Oc and Dc. based on original SILAC and RNAseq data. We established specific signatures for Oc and Dc including genes and proteins of unknown functions. In particular. we showed that Oc and Dc have the same α and β tubulin isotypes repertoire but that Oc express much more β tubulin isotype Tubb6. In both mouse and human Oc. we demonstrate that elevated expression of Tubb6 in Oc is necessary for correct podosomes organization and thus for the structure of the sealing zone. which sustains the bone resorption apparatus. Hence. lowering Tubb6 expression hindered Oc resorption activity. Overall. we highlight here potential new regulators of Oc and Dc biology and illustrate the functional importance of the tubulin isotype repertoire in the biology of differentiated cells.Summary statementThis study provides original proteomic and transcriptomic data of primary myeloid cells. The analysis led to signatures for osteoclasts and for immature dendritic cells including potential new regulators of their specific biology. RNA interference showed in particular that ß tubulin isotype Tubb6 participates in osteoclast podosome patterning. sealing zone structure and in the resorption activity.

scholarly journals The Caenorhabditis elegans Microtubule-severing Complex MEI-1/MEI-2 Katanin Interacts Differently with Two Superficially Redundant β-Tubulin Isotypes

2004 ◽  
Vol 15 (1) ◽  
pp. 142-150 ◽  
Author(s):  
Chenggang Lu ◽  
Martin Srayko ◽  
Paul E. Mains
Keyword(s):  
Caenorhabditis Elegans ◽  
Genetic Background ◽  
Morphological Changes ◽  
Meiotic Spindle ◽  
Tubulin Isotypes ◽  
Microtubule Severing ◽  
Tubulin Isotype ◽  
Embryonic Viability ◽  
Β Tubulin

The microtubule-severing protein complex katanin is required for a variety of important microtubule-base morphological changes in both animals and plants. Caenorhabditis elegans katanin is encoded by the mei-1 and mei-2 genes and is required for oocyte meiotic spindle formation and must be inactivated before the first mitotic cleavage. We identified a mutation, sb26, in the tbb-2 β-tubulin gene that partially inhibits MEI-1/MEI-2 activity: sb26 rescues lethality caused by ectopic MEI-1/MEI-2 expression during mitosis, and sb26 increases meiotic defects in a genetic background where MEI-1/MEI-2 activity is lower than normal. sb26 does not interfere with MEI-1/MEI-2 microtubule localization, suggesting that this mutation likely interferes with severing. Tubulin deletion alleles and RNA-mediated interference revealed that TBB-2 and the other germline enriched β-tubulin isotype, TBB-1, are redundant for embryonic viability. However, limiting MEI-1/MEI-2 activity in these experiments revealed that MEI-1/MEI-2 preferentially interacts with TBB-2–containing microtubules. Our results demonstrate that these two superficially redundant β-tubulin isotypes have functionally distinct roles in vivo.

scholarly journals The Roles of β-Tubulin Mutations and Isotype Expression in Acquired Drug Resistance

2007 ◽  
Vol 3 ◽  
pp. 117693510700300 ◽  
Author(s):  
J. Torin Huzil ◽  
Ke Chen ◽  
Lukasz Kurgan ◽  
Jack A. Tuszynski
Keyword(s):  
Drug Resistance ◽  
Rational Design ◽  
Resistant Cell ◽  
Microtubule Assembly ◽  
Acquired Drug Resistance ◽  
Tubulin Isotypes ◽  
Microtubule Disruption ◽  
Tubulin Isotype ◽  
Β Tubulin ◽  
Isotype Expression

The antitumor drug paclitaxel stabilizes microtubules and reduces their dynamicity, promoting mitotic arrest and eventually apoptosis. Upon assembly of the α/β-tubulin heterodimer, GTP becomes bound to both the α and β-tubulin monomers. During microtubule assembly, the GTP bound to β-tubulin is hydrolyzed to GDP, eventually reaching steady-state equilibrium between free tubulin dimers and those polymerized into microtubules. Tubulin-binding drugs such as paclitaxel interact with β-tubulin, resulting in the disruption of this equilibrium. In spite of several crystal structures of tubulin, there is little biochemical insight into the mechanism by which anti-tubulin drugs target microtubules and alter their normal behavior. The mechanism of drug action is further complicated, as the description of altered β-tubulin isotype expression and/or mutations in tubulin genes may lead to drug resistance as has been described in the literature. Because of the relationship between β-tubulin isotype expression and mutations within β-tubulin, both leading to resistance, we examined the properties of altered residues within the taxane, colchicine and Vinca binding sites. The amount of data now available, allows us to investigate common patterns that lead to microtubule disruption and may provide a guide to the rational design of novel compounds that can inhibit microtubule dynamics for specific tubulin isotypes or, indeed resistant cell lines. Because of the vast amount of data published to date, we will only provide a broad overview of the mutational results and how these correlate with differences between tubulin isotypes. We also note that clinical studies describe a number of predictive factors for the response to anti-tubulin drugs and attempt to develop an understanding of the features within tubulin that may help explain how they may affect both microtubule assembly and stability.

scholarly journals Identification of key interactions of benzimidazole resistance-associated amino acid mutations in Ascaris β-tubulins by molecular docking simulations

2021 ◽  
Author(s):  
Ben Paul Jones ◽  
Arnoud H. M. van Vliet ◽  
E. James La Course ◽  
Martha Betson
Keyword(s):  
Amino Acid ◽  
Obvious Effect ◽  
Middle Income ◽  
Docking Simulations ◽  
In Silico Docking ◽  
Tubulin Isotypes ◽  
Tubulin Isotype ◽  
Amino Acid Mutations ◽  
Dynamics Simulations ◽  
Β Tubulin

Ascaris species are soil-transmitted helminths that infect humans and livestock mainly in low and middle-income countries. Benzimidazole (BZ) class drugs have predominated for many years in the treatment of Ascaris infections, but persistent use of BZs has already led to widespread resistance in other nematodes, and treatment failure is emerging for Ascaris. Benzimidazoles act by binding to β-tubulin proteins and destabilising microtubules. Three mutations in the β-tubulin protein family are associated with BZ resistance. Seven shared β-tubulin isotypes were identified in Ascaris lumbricoides and A. suum genomes. Benzimidazoles were predicted to bind to all β-tubulin isotypes using in silico docking, demonstrating that the selectivity of BZs to interact with one or two β-tubulin isotypes is likely the result of isotype expression levels affecting the frequency of interaction. Ascaris β-tubulin isotype A clusters with helminth β-tubulins previously shown to interact with BZ. Molecular dynamics simulations using β-tubulin isotype A highlighted the key role of amino acid E198 in BZ-β-tubulin interactions. Simulations indicated that mutations at amino acids E198A and F200Y alter binding of BZ, whereas there was no obvious effect of the F167Y mutation. In conclusion, the key interactions vital for BZ binding with β-tubulins have been identified and show how mutations can lead to resistance in nematodes.

scholarly journals Identification of Key Interactions of Benzimidazole Resistance-Associated Amino Acid Mutations in Ascaris β-Tubulins By Molecular Docking Simulations

2021 ◽  
Author(s):  
Ben P. Jones ◽  
Arnoud H.M. Vliet ◽  
E. James LaCourse ◽  
Martha Betson
Keyword(s):  
Amino Acid ◽  
Obvious Effect ◽  
Middle Income ◽  
Docking Simulations ◽  
Tubulin Isotypes ◽  
Tubulin Isotype ◽  
Amino Acid Mutations ◽  
Dynamics Simulations ◽  
Tubulin Protein ◽  
Β Tubulin

Abstract Ascaris species are soil-transmitted helminths that infect humans and livestock mainly in low and middle-income countries. Benzimidazole (BZ) class drugs have predominated for many years in the treatment of Ascaris infections, but persistent use of BZs has already led to widespread resistance in other nematodes, and treatment failure is emerging for Ascaris. Benzimidazoles act by binding to β-tubulin proteins and destabilising microtubules. Three mutations in the β-tubulin protein family are associated with BZ resistance. Seven shared β-tubulin isotypes were identified in Ascaris lumbricoides and A. suum genomes. Benzimidazoles were predicted to bind to all β-tubulin isotypes using in silico docking, demonstrating that the selectivity of BZs to interact with one or two β-tubulin isotypes is likely the result of isotype expression levels affecting the frequency of interaction. Ascaris β-tubulin isotype A clusters with helminth β-tubulins previously shown to interact with BZ. Molecular dynamics simulations using β-tubulin isotype A highlighted the key role of amino acid E198 in BZ-β-tubulin interactions. Simulations indicated that mutations at amino acids E198A and F200Y alter binding of BZ, whereas there was no obvious effect of the F167Y mutation. In conclusion, the key interactions vital for BZ binding with β-tubulins have been identified and show how mutations can lead to resistance in nematodes.

scholarly journals 2-(m-Azidobenzoyl)taxol binds differentially to distinct β-tubulin isotypes

2016 ◽  
Vol 113 (40) ◽  
pp. 11294-11299 ◽  
Author(s):  
Chia-Ping Huang Yang ◽  
Eng-Hui Yap ◽  
Hui Xiao ◽  
Andras Fiser ◽  
Susan Band Horwitz
Keyword(s):  
Mammalian Cells ◽  
Bovine Brain ◽  
Drug Binding ◽  
Dynamic Simulations ◽  
Altered Expression ◽  
Stabilizing Agents ◽  
Tubulin Isotypes ◽  
Tubulin Isotype ◽  
Different Sources ◽  
Β Tubulin

There are seven β-tubulin isotypes present in distinct quantities in mammalian cells of different origin. Altered expression of β-tubulin isotypes has been reported in cancer cell lines resistant to microtubule stabilizing agents (MSAs) and in human tumors resistant to Taxol. To study the relative binding affinities of MSAs, tubulin from different sources, with distinct β-tubulin isotype content, were specifically photolabeled with a tritium-labeled Taxol analog, 2-(m-azidobenzoyl)taxol, alone or in the presence of MSAs. The inhibitory effects elicited by these MSAs on photolabeling were distinct for β-tubulin from different sources. To determine the exact amount of drug that binds to different β-tubulin isotypes, bovine brain tubulin was photolabeled and the isotypes resolved by high-resolution isoelectrofocusing. All bands were analyzed by mass spectrometry following cyanogen bromide digestion, and the identity and relative quantity of each β-tubulin isotype determined. It was found that compared with other β-tubulin isotypes, βIII-tubulin bound the least amount of 2-(m-azidobenzoyl)taxol. Analysis of the sequences of β-tubulin near the Taxol binding site indicated that, in addition to the M-loop that is known to be involved in drug binding, the leucine cluster region of βIII-tubulin contains a unique residue, alanine, at 218, compared with other isotypes that contain threonine. Molecular dynamic simulations indicated that the frequency of Taxol-accommodating conformations decreased dramatically in the T218A variant, compared with other β-tubulins. Our results indicate that the difference in residue 218 in βIII-tubulin may be responsible for inhibition of drug binding to this isotype, which could influence downstream cellular events.

Higher CD1a Levels Correlate with PD-L1 Expression and Predict Worse Overall Survival in Triple-Negative Breast Carcinoma

Breast Care ◽  
2021 ◽  
pp. 1-9
Author(s):  
Jian Zheng ◽  
Yuntao Wei ◽  
Xiaoxi Li ◽  
Zhan Shen ◽  
Yong Zhang ◽  
...  
Keyword(s):  
Overall Survival ◽  
Dendritic Cells ◽  
Lymph Node ◽  
Breast Carcinoma ◽  
Triple Negative ◽  
Carcinoma Tissue ◽  
Kaplan Meier ◽  
Immature Dendritic Cells ◽  
Triple Negative Breast Carcinoma ◽  
High Median

Objective: The aim of this study was to measure the expression of PD-L1, CD1a (a marker for immature dendritic cells), and CD83 (a marker for mature dendritic cells) and further examine the associations of PD-L1, CD83, and CD1a with overall survival (OS) in triple-negative breast carcinoma patients. Methods: PD-L1, CD1a, and CD83 expression in breast carcinoma tissues and CD83 expression in lymph node tissues were examined by immunohistochemistry and tissue microarray in 159 patients. Patients were classified into the low, medium, and high PD-L1, CD1a, and CD83 levels. Pearson χ2 test was used to analyze the correlations between PD-L1, CD1a, and CD83. The Kaplan-Meier method was used to calculate the OS. Multivariate analysis was used to identify determinants of 3- and 5-year OS. Results: 25.1, 25.8, and 49.1% of the patients had low, medium, and high PD-L1 levels, respectively. PD-L1 levels significantly correlated with CD1a (r = 0.30409, p < 0.001) and CD83 levels (r = 0.6146, p < 0.001) in breast carcinoma tissue, as well as CD83 levels (r = 0.17508, p = 0.027) in lymph node. The median OS was 83 months (range 12–106), and the 3- and 5-year OS rates were 94.97% (95% CI 91.57–98.37) and 86.79% (95% CI 81.53–92.06), respectively. Moreover, patients with high median CD1a levels had a significantly lower 5-year OS rate (75.6%) than those with low median CD1a levels (93.5%, p = 0.038). Conclusion: PD-L1, CD1a, and CD83 are variably expressed in triple-negative breast carcinoma tissues, and PD-L1 expression correlates with CD1a and CD83. Higher CD1a levels correlate with PD-L1 expression and predict worse OS in triple-negative breast carcinoma.

scholarly journals Class III β-Tubulin isotype (β III) in the adrenal medulla: I. Localization in the developing human adrenal medulla

1998 ◽  
Vol 250 (3) ◽  
pp. 335-343 ◽  
Author(s):  
Christos D. Katsetos ◽  
George Karkavelas ◽  
Mary M. Herman ◽  
Stanley A. Vinores ◽  
Javier Provencio ◽  
...  
Keyword(s):  
Adrenal Medulla ◽  
Class Iii ◽  
Tubulin Isotype ◽  
Β Tubulin

scholarly journals Six mouse alpha-tubulin mRNAs encode five distinct isotypes: testis-specific expression of two sister genes.

1986 ◽  
Vol 6 (7) ◽  
pp. 2409-2419 ◽  
Author(s):  
A Villasante ◽  
D Wang ◽  
P Dobner ◽  
P Dolph ◽  
S A Lewis ◽  
...  
Keyword(s):  
Duplication Event ◽  
Developmental Expression ◽  
Untranslated Regions ◽  
Coding Region ◽  
Specific Expression ◽  
Translational Initiation ◽  
Alpha Tubulin ◽  
Tubulin Isotypes ◽  
Tubulin Isotype ◽  
Genes Encoding

Five mouse alpha-tubulin isotypes are described, each distinguished by the presence of unique amino acid substitutions within the coding region. Most, though not all of these isotype-specific amino acids, are clustered at the carboxy terminus. One of the alpha-tubulin isotypes described is expressed exclusively in testis and is encoded by two closely related genes (M alpha 3 and M alpha 7) which have homologous 3' untranslated regions but which differ at multiple third codon positions and in their 5' untranslated regions. We show that a subfamily of alpha-tubulin genes encoding the same testis-specific isotype also exists in humans. Thus, we conclude that the duplication event leading to a pair of genes encoding a testis-specific alpha-tubulin isotype predated the mammalian radiation, and both members of the duplicated sequence have been maintained since species divergence. A second alpha-tubulin gene, M alpha 6, is expressed ubiquitously at a low level, whereas a third gene, M alpha 4, is unique in that it does not encode a carboxy-terminal tyrosine residue. This gene yields two transcripts: a 1.8-kilobase (kb) mRNA that is abundant in muscle and a 2.4-kb mRNA that is abundant in testis. Whereas the 1.8-kb mRNA encodes a distinct alpha-tubulin isotype, the 2.4-kb mRNA is defective in that the methionine residue required for translational initiation is missing. Patterns of developmental expression of the various alpha-tubulin isotypes are presented. Our data support the view that individual tubulin isotypes are capable of conferring functional specificity on different kinds of microtubules.

Sign in / Sign up

Export Citation Format

Share Document