• BMB Reports
• /
• v.40 no.2
• /
• pp.218-225
• /
• 2007

In Arabidopsis thaliana, the microtubule-associated protein AtMAP65-1 shows various functions on microtubule dynamics and organizations. However, it is still an open question about whether AtMAP65-1 binds to tubulin dimers and how it regulates microtubule dynamics. In present study, the tubulin-binding activity of AtMAP65-1 was investigated. Pull-down and co-sedimentation exp eriments demonstrated that AtMAP65-1 bound to tubulin dimers,at a molar ratio of 1 : 1. Cross-linking experiments showed that AtMAP65-1 bound to tubulin dimers by interacting with $\alpha$-tubulin of the tubulin heterodimer. Interfering the bundling effect of AtMAP65-1 by addition of salt and monitoring the tubulin assembly, the experiment results indicated that AtMAP65-1 promoted tubulin assembly by interacting with tubulin dimers. In addition, five truncated versions of AtMAP65-1, namely AtMAP65-1 $\Delta$N339 (amino acids 340-587); AtMAP65-1 $\Delta$N494 (amino acids 495-587); AtMAP65-1 340-494 (amino acids 340-494); AtMAP65-1 $\Delta$C495 (amino acids 1-494) and AtMAP65-1 $\Delta$C340 (amino acids 1-339), were tested for their binding activities and roles in tubulin polymerization in vitro. Four (AtMAP65-1 $\Delta$N339, $\Delta$N494, AtMAP65-1 340-494 and $\Delta$C495) from the five truncated proteins were able to co-sediment with microtubules, and three (AtMAP65-1 $\Delta$N339, $\Delta$N494 and AtMAP65-1 340-494) of them could bind to tubulin dimers in vitro. Among the three truncated proteins, AtMAP65-1 $\Delta$N339 showed the greatest activity to promote tubulin polymerization, AtMAP65-1 $\Delta$N494 exhibited almost the same activity as the full length protein in promoting tubulin assembly, and AtMAP65-1 340-494 had minor activity to promote tubulin assembly. On the contrast, AtMAP65-1 $\Delta$C495, which bound to microtubules but not to tubulin dimers, did not affect tubulin assembly. Our study suggested that AtMAP65-1 might promote tubulin assembly by binding to tubulin dimers in vivo.

• The Plant Pathology Journal
• /
• v.15 no.1
• /
• pp.68-71
• /
• 1999

To illustrate the action mechanism of pencycuron on Rhizoctonia solani, two experiments were conducted including the comparison of amino acids of $\beta$-tubulin between R-C (sensitive isolate) and Rh-131 (non-sensitive isolate), and the inhibitory effect of pencycuron on tubulin assembly in vitro. Both $\beta$-tubulin genes of R-C and Rh-131 proved to have 1,582 nucleotides encoding a protein of 445 amino acids, showing 98% homology in amino acid sequences between them. It was found that codons at 103, 236, and 267 for lysine (AGG), valine (GTC) and isoleucine (ATT) in R-C were replaced by codons for methionine (ATG), isoleucine (ATT) and methionine (ATG) in Rh-131, respectively. No inhibitory effect of pencycuron on the tubulin assembly was observed. It suggests that pencycuron may have no direct inhibitory effects on the assembly of tubulin at least in vitro.

• Molecules and Cells
• /
• v.38 no.8
• /
• pp.705-714
• /
• 2015

We investigated the role of HDAC3 in anti-cancer drug-resistance. The expression of HDAC3 was decreased in cancer cell lines resistant to anti-cancer drugs such as celastrol and taxol. HDAC3 conferred sensitivity to these anti-cancer drugs. HDAC3 activity was necessary for conferring sensitivity to these anti-cancer drugs. The down-regulation of HDAC3 increased the expression of MDR1 and conferred resistance to anti-cancer drugs. The expression of tubulin ${\beta}3$ was increased in drug-resistant cancer cell lines. ChIP assays showed the binding of HDAC3 to the promoter sequences of tubulin ${\beta}3$ and HDAC6. HDAC6 showed an interaction with tubulin ${\beta}3$. HDAC3 had a negative regulatory role in the expression of tubulin ${\beta}3$ and HDAC6. The down-regulation of HDAC6 decreased the expression of MDR1 and tubulin ${\beta}3$, but did not affect HDAC3 expression. The down-regulation of HDAC6 conferred sensitivity to taxol. The down-regulation of tubulin ${\beta}3$ did not affect the expression of HDAC6 or MDR1. The down-regulation of tubulin ${\beta}3$ conferred sensitivity to anti-cancer drugs. Our results showed that tubulin ${\beta}3$ serves as a downstream target of HDAC3 and mediates resistance to microtubule-targeting drugs. Thus, the HDAC3-HDAC6-Tubulin ${\beta}$ axis can be employed for the development of anti-cancer drugs.

• Parasites, Hosts and Diseases
• /
• v.47 no.3
• /
• pp.287-291
• /
• 2009

The ${\alpha}/{\beta}$-tubulin heterodimer is the basic subunit of microtubules in eukaryotes. Polyclonal antibodies specific to recombinant ${\alpha}$-tubulin of Giardia lamblia were made, and found effective as a probe to specifically detect G. lamblia by immunofluorescence assays. Nucleotide sequences of ${\alpha}$-tubulin genes were compared between G. lamblia WB and GS strains, prototypes of assemblage A and assemblage B, respectively. A set of primers was designed and used to amplify a portion of the ${\alpha}$-tubulin gene from G. lamblia. PCR-RFLP analysis of this ${\alpha}$-tubulin PCR product successfully differentiated G. lamblia into 2 distinct groups, assemblages A and B.Theresults indicate that ${\alpha}$-tubulin can be used as a molecular probe to detect G.lamblia.

• The Korean Journal of Mycology
• /
• v.25 no.1 s.80
• /
• pp.1-5
• /
• 1997

The cDNA encoding ${\beta}-tubulin$ of Pleurotus sajor-caju was isolated using an internal gene segment probe amplified by polymerase chain reaction (PCR) of genomic DNA and by cDNA library screening. The cDNA was consisted of 1560 nucleotides(nt), including a 5'-untranslation region (UTR) of 27nt, an open reading frame (ORF) of 1341nt, and a 3'-UTR of 191nt. The ORF encoded a protein of 446 amino acids(aa), which shows over 80% homology with ${\beta}-tubulins$ of other filamentous fungi. Southern hybridization analysis showed that there were two isotypes of ${\beta}-tubulin$ genes in P. sajor-caju. Through sequence analysis we found that ${\beta}-tubulin$ had a unusual $Cys^{165}$ residue, which might be a significant factor for the insensitivity of fungi to fungicide benomyl.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.39 no.1
• /
• pp.22-28
• /
• 2019

We previously isolated 9 clones that show stronger signal compared to Bombyx mori cytoplasmic actin gene (BmA3) by using a dot blot hybridization. In this study, we focused on one clone among these clones which has high amino acid similarity with ${\beta}$-tubulin gene of B. mori. This clone was ubiquitously expressed in all tissues and developmental stage of B. mori. As result of promoter assay using dual luciferase assay system, we found the highest transcription activity region (-750/-1) in the 5'-flanking region of ${\beta}$-tubulin gene, which has about 47 fold more intensive promoter activity than BmA3 promoter. Moreover, the ${\beta}$-tubulin promoter was normally regulated in Bm5, Sf9, and S2 cells. Therefore, we suggest that ${\beta}$-tubulin promoter may be used more powerful and effectively for transgene expression in various insects containing B. mori as a universal promoter.

• Journal of Microbiology and Biotechnology
• /
• v.11 no.5
• /
• pp.876-879
• /
• 2001

${\gamma}$ -Tubulin is an essential component involved in microtubule nucleation. The present work examined whether the fast proliferation of cancer cells can be retarded by the depletion of ${\gamma}$ -tubulin expression. Two different gastric cancer cell lines and one control cell line were treated with antisence oligonucleotides complementary to the messenger RNA of ${\gamma}$ -tubulin. The$[^3H]$ -thymidine incorporation in the two gastric cancer cell lines, SNU-1 and SNU-216, was dramatically reducd by treatment with the ${\gamma}$ -tubulin antisense oligonucleotides in a dosage-dependent manner. In contrast, the control cell line, NIH/3T3, showed no significant effect from the antisense oligonucleotides even at a high concentration. The ablation of ${\gamma}$ -tubulin expression in the tumor cells resulted in an altered DNA synthesis during mitosis and it decreased the cell progression. Accordingly, the use of antisense oligonucleotides may be an effective way of inhibiting the proliferation of human gastric cancers.

• Applied Microscopy
• /
• v.30 no.1
• /
• pp.45-59
• /
• 2000

Cis-platin is a widely used anticancer drug against certain solid tumors such as malignant ovarian tumor, malignant carcinoma of head and neck, bladder cancer and cervical cancer of uterus, and its major mechanism of action is inhibition of DNA synthesis of the tumor cell. To investigate the inhibitory effects of cis-platin on the ciliogensis of the ciliated cells in the mucosa of oviduct, the author pursued the alterations of $\alpha-tubulin$, which is the main constituent of the microtubles in cilia, after cis-platin treatment. To eliminate the possible variations due to ovarian cycle, female Spargue-Dawley rats ($150\sim200gm$ in B.W.) were pretreated with estradiol benzoate (20 mg/kg, once a day, for 4 consecutive days). Animals were administrated with cis-platin (6 mg/kg, i.p.) and sacrificed at 1day, 3days, 5days and 7days after treatment, respectively. Immunohistochemistry for $\alpha-tubulin$ using mouse anti-rat $\alpha-tubulin$ monoclonal antibody as primary antibody was done. Immunogold electronmicroscopy for intracellular distributions of $\alpha-tubulin$ was also performed with same primary antibody and Goat anti- mouse IgM which is preconjugated with gold particles of 15 nm as secondary antibody. The results obtained were as follows; 1. Strong immunoreactivity of $\alpha-tubulin$ was observed in ciliated cells of oviducts at 1, 3 and 5 days after estradiol pretreatment. 2. Weak immunoreactivity of $\alpha-tubulin$ was observed in ciliated cells of oviducts at 1 and 3 days after cis-platin treatment but it was recovered to strong immunoreactivity in 5 days 3. In immunogold electronmicroscopy, density of gold particles for $\alpha-tubulin$ reactions was decreased in apical cytoplasm, but few changes were observed in basal body or cilia at 1 and 3 days after cis-platin treatment. From these above results, it is indicated that synthesis of $\alpha-tubulin$ in ciliated cells of rat oviduct is inhibited by cis-platin treatment.

• Proceedings of the KSAR Conference
• /
• 2002.06a
• /
• pp.49-49
• /
• 2002

γ - tubulin is an essential, invariant constitutive centrosomal protein, which plays key roles in microtubule patterning and defining the microtubule intrinsic polarity. Although γ-tubulin was also present in cattle oocytes and zygotes, no details have been provided on its recruitment and localization to date. In this study, we determined γ-tubulin distribution chronologically in conjunction with microtubule dynamics during fertilization and parthenogenesis, with a view to understanding the molecular basis of zygotic centrosome reconstitution in cattle. (omitted)

• Bulletin of Food Technology
• /
• v.17 no.4
• /
• pp.117-128
• /
• 2004

Sulforaphane은 브로컬리나 십자화과 채소중의 glucoraphanin의 가수분해 산물인 isothiocyanate로서 이는 detoxification 효소의 phase II를 일으키는 것으로 나타났고 설치류에서 화학적으로 발생된 유선 종양을 억제하고 최근에는 대장암 세포에서 cell cycle arrest와 apoptosis를 일으킨다고 알려져 왔다. 여기서는 SUL이 Human MammaryMCF-7 adenocarcinoma 세포의 증폭을 억제하는 역할을 제시하였다. MCF-7 cell에 15umol/L SUL을 처리하였을 때 G2/M cell cycle이 arrest를 보였고 cyclin B1 protein이 24시간 이내에 증가하였다. 15umol/L의 SUL은 in vivo 상에서 histon Hl의 인산화를 유도하고, 초기 mitosis에서 cell을block하며 mitotic microtuble의 중합화를 방해하였다. In vitro 상에서 정제된 bovine braintubulin에 대한 SUL을 고농도로 투여했을 때, tubulin의 중합율과 총 tubulin 중합도의 억제를 보였다. 덧붙여서, isothiocyanate를 함유하는 SULanalog로 처리된 정제 tubulin도 비슷하게 저해를 받았다. 본 연구는 SUL이 mitotic cell cyclearrest를 포함한 mammary cancer 억제력을 가진 것과, 이러한 기작으로 정상적인 tubulin 중합화및 microtubule dynamic에 한층 효과적인 영향을 준다는 것을 제시하였다.