Tubulin Dotaz Zobrazit nápovědu
- MeSH
- eukaryotické buňky anatomie a histologie fyziologie metabolismus MeSH
- tubulin MeSH
- Publikační typ
- přehledy MeSH
Cíl studie: Objasnit, zda lze na základě vyšetření protilátek proti fragmentům neuronálního cytoskeletu u pacientů s demencí odlišit primárně atroficko-degenerativní postižení od postižení vaskulárního původu. Metodika: Soubor 37 pacientů se syndromem demence zahrnoval 8 pacientů s Alzheimerovou chorobou (AD), 8 pacientů s frontotemporální lobární degenerací (FTLD), 11 pacientů s vaskulární demencí (VD) a 10 pacientů se smíšenou demencí (SD). Kontrolní skupinu tvořilo 10 osob bez poruchy kognitivních funkcí. Diagnóza byla stanovena na základě klinického vyšetření, vyhodnocení MRI a laboratorních metod (stanovení fosfo-tau-proteinu, tau-proteinu, beta-amyloidu v mozkomíšním moku). Séra a mozkomíšní moky (MM) těchto pacientů byly vyšetřeny metodou ELISA na přítomnost specifických protilátek proti neuronálnímu cytoskeletu, mikrotubulární podjednotky – beta-tubulinu (btcIII). Výsledky: Hladiny protilátek IgM v MM ani v séru nebyly ve skupinách pacientů s demencí statisticky významně odlišné od kontrolní skupiny. Pozitivní titry IgG anti-btcIII protilátek v MM byly prokázány u 56 % pacientů s VD, u 33% pacientů se SD a u 25 % pacientů s FTLD. Pozitivní titry IgG protilátek proti btcIII v séru byly nalezeny u 40 % pacientů se SD, u 36% pacientů s VD a 13 % pacientů s FTLD. Žádný pozitivní výsledek IgG protilátek v séru ani v MM ve skupině pacientů s AD ani v kontrolní skupině zaznamenán nebyl. Závěr: Pozitivní titry protilátek třídy IgG proti btcIII byly v séru a v MM prokázány u pacientů s VD a SD na rozdíl od pacientů s AD. Po ověření výsledků na větším souboru pacientů může vyšetření těchto specifických protilátek zpřesnit diferenciální diagnostiku AD, SD a VD.
The aim: To elucidate whether primarily atrophic degenerative affection can be differentiated from the affection of vascular origin by examining antibodies against fragments of the neuronal cytoskeleton in patients with dementia. Methods: A set of 37 patients with a syndrome of dementia involved 8 patients with Alzheimer´s disease (AD), 8 patients with frontotemporal lobar degeneration (FTLD), 11 patients with vascular dementia (VD), and 10 patients with mixed dementia (MD). A control set consisted of 10 subjects without disturbed cognitive functions. The diagnosis was established by means of basic clinical examinations, evaluations of MRI and of laboratory methods (determination of phospho-tau protein, tau protein, beta-amyloid in the cerebrospinal fluid). The serums and cerebrospinal fluids (CSF) of these patients were examined using ELISA method for the presence of specific antibodies against the neuronal cytoskeleton, microtubular subunit – beta-tubulin (btcIII). Results: In the sets of patients with dementia the levels of IgM antibodies both in CSF and serum did not differ statistically significantly from those in the controls. Positive titres of IgG anti-btcIII antibodies in CSF were shown in 56% patients with VD, in 33% patients with MD, and in 25% patients with FTLD. Positive titres of IgG antibodies against btcIII in serum were revealed in 40% patients with MD, in 36% patients with VD, and in 13% patients with FTLD. No positive result of IgG antibodies in serum as well as in CSF was recorded in a set of patients with AD and in controls. Conclusion: Positive titres of antibodies of IgG class against btcIII in serum and CSF were detected in patients with VD and MD in contrast to patients with AD. After verifying the results in a larger set of subjects, the examination of these specific antibodies can make the differential diagnosis of AD, MD and VD more accurate.
- MeSH
- Alzheimerova nemoc diagnóza etiologie MeSH
- biologické markery MeSH
- demence diagnóza etiologie klasifikace MeSH
- diferenciální diagnóza MeSH
- finanční podpora výzkumu jako téma MeSH
- interpretace statistických dat MeSH
- lidé MeSH
- protilátky diagnostické užití krev MeSH
- tubulin diagnostické užití krev MeSH
- vaskulární demence diagnóza enzymologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- srovnávací studie MeSH
Microtubules composed of tubulin heterodimers represent highly dynamic structures. These structures are essential for basic cellular functions, such as cell division. Microtubules can grow or shrink in response to environmental signals, principally chemical cues. Here, we provide an alternative-physical-strategy to modulate tubulin properties and its self-assembly process. The conformation and electrical properties of tubulin subunits are modulated by nanosecond electropulse signals. The formed structures of electrically treated tubulin are tightly linked to the degree of conformational and electrical properties changes induced by nanosecond electropulses. This strategy opens a new way for controlling the self-assembly process in biomolecules as well as in bioinspired materials.
Highly conserved α- and β-tubulin heterodimers assemble into dynamic microtubules and perform multiple important cellular functions such as structural support, pathway for transport and force generation in cell division. Tubulin exists in different forms of isotypes expressed by specific genes with spatially- and temporally-regulated expression levels. Some tubulin isotypes are differentially expressed in normal and neoplastic cells, providing a basis for cancer chemotherapy drug development. Moreover, specific tubulin isotypes are overexpressed and localized in the nuclei of cancer cells and/or show bioenergetic functions through the regulation of the permeability of mitochondrial ion channels. It has also become clear that tubulin isotypes are involved in multiple cellular functions without being incorporated into microtubule structures. Understanding the mutations of tubulin isotypes specifically expressed in tumors and their post-translational modifications might help to identify precise molecular targets for the design of novel anti-microtubular drugs. Knowledge of tubulin mutations present in tubulinopathies brings into focus cellular functions of tubulin in brain pathologies such as Alzheimer's disease. Uncovering signaling pathways which affect tubulin functions during antigen-mediated activation of mast cells presents a major challenge in developing new strategies for the treatment of inflammatory and allergic diseases. γ-tubulin, a conserved member of the eukaryotic tubulin superfamily specialized for microtubule nucleation is a target of cell cycle and stress signaling. Besides its microtubule nucleation role, γ-tubulin functions in nuclear and cell cycle related processes. This special issue "Tubulin: Structure, Functions and Roles in Disease" contains eight articles, five of which are original research papers and three are review papers that cover diverse areas of tubulin biology and functions under normal and pathological conditions.
- MeSH
- Alzheimerova nemoc genetika metabolismus patologie MeSH
- lidé MeSH
- mikrotubuly genetika metabolismus patologie MeSH
- mutace MeSH
- nádorové proteiny genetika metabolismus MeSH
- nádory genetika metabolismus MeSH
- protein - isoformy MeSH
- tubulin genetika metabolismus MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- práce podpořená grantem MeSH
- úvodní články MeSH
- úvodníky MeSH
γ-Tubulins are highly conserved members of the tubulin superfamily essential for microtubule nucleation. Humans possess 2 γ-tubulin genes. It is thought that γ-tubulin-1 represents a ubiquitous isotype, whereas γ-tubulin-2 is found predominantly in the brain, where it may be endowed with divergent functions beyond microtubule nucleation. The molecular basis of the purported functional differences between γ-tubulins is unknown. We report discrimination of human γ-tubulins according to their electrophoretic and immunochemical properties. In vitro mutagenesis revealed that the differences in electrophoretic mobility originate in the C-terminal regions of the γ-tubulins. Using epitope mapping, we discovered mouse monoclonal antibodies that can discriminate between human γ-tubulin isotypes. Real time quantitative RT-PCR and 2-dimensional-PAGE showed that γ-tubulin-1 is the dominant isotype in fetal neurons. Although γ-tubulin-2 accumulates in the adult brain, γ-tubulin-1 remains the major isotype in various brain regions. Localization of γ-tubulin-1 in mature neurons was confirmed by immunohistochemistry and immunofluorescence microscopy on clinical samples and tissue microarrays. Differentiation of SH-SY5Y human neuroblastoma cells by all-trans retinoic acid, or oxidative stress induced by mitochondrial inhibitors, resulted in upregulation of γ-tubulin-2, whereas the expression of γ-tubulin-1 was unchanged. Fractionation experiments and immunoelectron microscopy revealed an association of γ-tubulins with mitochondrial membranes. These data indicate that in the face of predominant γ-tubulin-1 expression, the accumulation of γ-tubulin-2 in mature neurons and neuroblastoma cells during oxidative stress may denote a prosurvival role of γ-tubulin-2 in neurons.-Dráberová, E., Sulimenko, V., Vinopal, S., Sulimenko, T., Sládková, V., D'Agostino, L., Sobol, M., Hozák, P., Křen, L., Katsetos, C. D., Dráber, P. Differential expression of human γ-tubulin isotypes during neuronal development and oxidative stress points to γ-tubulin-2 prosurvival function.
- MeSH
- lidé MeSH
- mikrotubuly metabolismus MeSH
- neuroblastom metabolismus MeSH
- neurogeneze fyziologie MeSH
- neurony metabolismus MeSH
- oxidační stres fyziologie MeSH
- tubulin metabolismus MeSH
- vývojová regulace genové exprese fyziologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Microtubules, polymers of the heterodimeric protein αβ-tubulin, are indispensable for many cellular activities such as maintenance of cell shape, division, migration, and ordered vesicle transport. In vitro assays to study microtubule functions and their regulation by associated proteins require the availability of assembly-competent purified tubulin. However, tubulin is a thermolabile protein that rapidly converts into non-polymerizing state. For this reason it is usually stored at -80 °C to preserve its conformation and polymerization properties. In this chapter we describe a method for freeze-drying of assembly-competent tubulin in the presence of nonreducing sugar trehalose and methods enabling evaluation of tubulin functions in rehydrated samples.
- MeSH
- lyofilizace * MeSH
- proteiny chemie MeSH
- trehalosa chemie MeSH
- tubulin chemie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Microtubule dynamics is one of the major targets for new chemotherapeutic agents. This communication presents the synthesis and biological profiling of steroidal dimers based on estradiol, testosterone and pregnenolone bridged by 2,6-bis(azidomethyl)pyridine between D rings. The biological profiling revealed unique properties of the estradiol dimer including cytotoxic activities on a panel of 11 human cell lines, ability to arrest in the G2/M phase of the cell cycle accompanied with the attenuation of DNA/RNA synthesis. Thorough investigation precluded a genomic mechanism of action and revealed that the estradiol dimer acts at the cytoskeletal level by inhibiting tubulin polymerization. Further studies showed that estradiol dimer, but none of the other structurally related dimeric steroids, inhibited assembly of purified tubulin (IC50, 3.6 μM). The estradiol dimer was more potent than 2-methoxyestradiol, an endogenous metabolite of 17β-estradiol and well-studied microtubule polymerization inhibitor with antitumor effects that was evaluated in clinical trials. Further, it was equipotent to nocodazole (IC50, 1.5 μM), an antimitotic small molecule of natural origin. Both estradiol dimer and nocodazole completely and reversibly depolymerized microtubules in interphase U2OS cells at 2.5 μM concentration. At lower concentrations (50 nM), estradiol dimer decreased the microtubule dynamics and growth life-time and produced comparable effect to nocodazole on the microtubule dynamicity. In silico modeling predicted that estradiol dimer binds to the colchicine-binding site in the tubulin dimer. Finally, dimerization of the steroids abolished their ability to induce transactivation by estrogen receptor α and androgen receptors. Although other steroids were reported to interact with microtubules, the estradiol dimer represents a new structural type of steroid inhibitor of tubulin polymerization and microtubule dynamics, bearing antimitotic and cytotoxic activity in cancer cell lines.
- MeSH
- buněčný cyklus MeSH
- estradiol chemie farmakologie MeSH
- estrogeny chemie farmakologie MeSH
- lidé MeSH
- mikrotubuly účinky léků fyziologie MeSH
- modulátory tubulinu chemie farmakologie MeSH
- nádorové buňky kultivované MeSH
- nádory farmakoterapie metabolismus patologie MeSH
- polymerizace MeSH
- proliferace buněk MeSH
- tubulin chemie účinky léků MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Microsporidia are intracellular parasites of insects and other higher eukaryotes. The microsporidian Nosema philosamiae Talukdar, 1961 was isolated from the eri silkworm, Philosamia cynthia ricini Grote. In the present study, alpha- and beta-tubulin genes from N. philosamiae were characterized. The identity analysis of nucleotide and amino acid sequences indicated high similarity with species of Nosema Nägeli, 1857 sensu lato (nucleotide sequences, > or = 96.0%; amino acid sequences, > or = 99.0%). However, the tubulin genes of N. philosamiae share low sequence similarity with that of N. ceranae Fries, Feng, da Silva, Slemenda et Pieniazek, 1996 (strain BRL01) and a Nosema/Vairimorpha species. Phylogenies based on alpha-, beta- and combined alpha- plus beta-tubulin gene sequences showed that N. philosamiae, along with the true Nosema species, forms a separate clade with a high bootstrap value, with N. ceranae BRL01 forming a clade of its own. The results indicated that the alpha- and beta-tubulin sequences may be useful as a diagnostic tool to discriminate the true Nosema group from the Nosema/Vairimorpha group.
Microtubules, polymers of the heterodimeric protein αβ-tubulin, are indispensable for many cellular activities such as maintenance of cell shape, division, migration, and ordered vesicle transport. In vitro assays to study microtubule functions and their regulation by associated proteins require the availability of assembly-competent purified tubulin. However, tubulin is a thermolabile protein that rapidly converts into a nonpolymerizing state. For this reason, it is usually stored at -80 °C or liquid nitrogen to preserve its conformation and polymerization properties. In this chapter, we describe a method for freeze-drying of assembly-competent tubulin in the presence of nonreducing sugar trehalose, and methods enabling the evaluation of tubulin functions in rehydrated samples.
- MeSH
- lidé MeSH
- lyofilizace MeSH
- stabilita proteinů MeSH
- trehalosa chemie MeSH
- tubulin chemie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
