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Tobamoviruses, mostly isolated from solanaceous plants, may represent
ancient virus lineages that have codiverged with their hosts. Recently
completed nucleotide sequences of six nonsolanaceous tobamoviruses allowed
assessment of the codivergence hypothesis and support a third subgroup
within tobamoviruses. The genomic sequences of 12 tobamoviruses and the
partial sequences of 11 others have been analyzed. Comparisons of the
predicted protein sequences revealed three clusters of tobamoviruses,
corresponding to those infecting solanaceous species (subgroup 1), those
infecting cucurbits and legumes (subgroup 2), and those infecting
crucifers. The orchid-infecting odontoglossum ringspot tobamovirus was
associated with subgroup 1 genomes by its coat and movement protein
sequences, but with the crucifer-pathogenic tobamoviruses by the remainder
of its genome, suggesting that it is the progeny of a recombinant. For four
of five genomic regions, subgroup 1 and 3 genomes were equidistant from a
subgroup 2 genome chosen for comparison, suggesting uniform rates of
evolution. A phylogenetic tree of plant families based on the tobamoviruses
they harbor was congruent with that based on rubisco sequences but had a
different root, suggesting that codivergence was tempered by rare events of
viruses of one family colonizing another family. The proposed subgroup 3
viruses probably have an origin of virion assembly in the movement protein
gene, a large (25-codon) overlap of movement and coat protein open reading
frames, and a comparably shorter genome. Codon-position- dependent base
compositions and codon prevalences suggested that the coat protein frame of
the overlap region was ancestral. Bootstrapped parsimony analysis of the
nucleotides in the overlap region and of the sequences translated from the
-1 frame (the subgroup 3 movement protein frame) of this region produced
trees inconsistent with those deduced from other regions. The results are
consistent with a model in which a no or short overlap organization was
ancestral. Despite encoding of subgroup 2 and 3 movement protein C-termini
by nonhomologous nucleotides, weak similarities between their amino acid
sequences suggested convergent sequence evolution.
相似文献
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Hsu PC Hour TC Liao YF Hung YC Liu CC Chang WH Kao MC Tsay GJ Hung HC Liu GY 《Apoptosis : an international journal on programmed cell death》2006,11(3):389-399
Prolactin has more than 300 separate functions including affecting mammary growth, differentiation, secretion and anti-apoptosis.
In the previous studies, prolactin induced Bcl-2 expression to prevent apoptosis and also provoked the activity of ornithine
decarboxylase (ODC). Our previous data showed that ODC overexpression upregulates Bcl-2 and prevents tumor necrosis factor
alpha (TNF-α)- and methotrexate (MTX)-induced apoptosis. Here, we further investigate whether prolactin prevents MTX-induced
apoptosis through inducing ODC activity and the relationship between ODC and Bcl-2 upon prolactin stimulation. Prolactin prevented
MTX-induced apoptosis in a dose-dependent manner in HL-60 cells. Following prolactin stimulation, ODC enzyme activity also
shows an increase in a dose-dependent manner, expressing its maximum level at 3 h, and rapidly declining thereafter. Prolactin-induced
ODC activity is completely blocked by a protein kinase C delta (PKCδ) inhibitor, rottlerin. However, there are no changes
in the expressions of ODC mRNA and protein level after prolactin stimulus. It indicates that prolactin may induce ODC activity
through the PCKδ pathway. Besides, Bcl-2 expresses within 1 h of prolactin treatment and this initiating effect of prolactin
is not inhibited by alpha-difluoromethylornithine (DFMO). However, Bcl-2 is further enhanced following prolactin stimulation
for 4 h and this enhancement is blocked by DFMO. Bcl-2 has no effect on ODC activity and protein levels, but ODC upregulates
Bcl-2, which is inhibited by DFMO. Overall, there are two different forms of prolactin effect, it induces Bcl-2 primarily,
and following this it stimulates ODC activity. Consequently induced ODC activity further enhances the expression of Bcl-2.
The anti-apoptotic effect of prolactin is diminished by DFMO and recovered by putrescine. Obviously, ODC activity is one basis
for the anti-apoptotic mechanisms of prolactin. A Bcl-2 inhibitor, HA14-1, together with DFMO, completely blocks the anti-apoptotic
effects of prolactin. These results suggest that increasing ODC activity is another way of prolactin preventing MTX-induced
apoptosis and that this induction of ODC activity enhances the expression of Bcl-2 strongly enough to bring about the anti-apoptotic
function. 相似文献
54.
Liu CH Huang JD Huang SW Hour TC Huang YK Hsueh YM Chiou HY Lee TC Jan KY Chen CJ Pu YS 《Journal of biomedical science》2008,15(2):261-269
The study sought to explore if androgen receptor gene (AR) polymorphisms are associated with the risk of urothelial carcinoma (UC) which is male-predominant. AR CAG and GGN repeat lengths were analyzed in 277 UC cases and 280 age and sex-matched controls by direct sequencing of leukocyte
DNA. Smoking habits were obtained using a structured questionnaire interview. Relative risks were compared between groups
categorized by all possible cutoffs of AR CAG and GGN repeat lengths. Men and women who had 23 and 44 (cumulative) CAG repeats had a significantly greater risk of
UC, respectively (OR 2.09, 95% CI: 1.05–4.17, p = 0.036 and OR 4.95, 95% CI: 1.56–15.73, p = 0.007). Amongst males who were medium-dose cigarette smokers, those who had 23 CAG and shorter GGN (<22) repeats, had an
elevated risk than those with longer CAG and GGN (OR 4.32 and 4.57, p = 0.034 and 0.042, respectively). However, neither CAG nor GGN affected the UC risk in non-smokers or heavy smokers (≥25
packs per day-years). AR CAG polymorphism may affect the risk of UC in both genders. In addition, AR polymorphisms may influence carcinogenic effect of medium-dose of cigarette smoking in men. 相似文献
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Nasser Hashemi Goradel Farshid Ghiyami‐ Hour Babak Negahdari Ziba Vaisi Malekshahi Milad Hashemzehi Aria Masoudifar Hamed Mirzaei 《Journal of cellular biochemistry》2018,119(1):95-104
Cardiovascular diseases are known as one of major causes of morbidity and mortality worldwide. Despite the many advancement in therapies are associated with cardiovascular diseases, it seems that finding of new therapeutic option is necessary. Cell therapy is one of attractive therapeutic platforms for treatment of a variety of diseases such as cardiovascular diseases. Among of various types of cell therapy, stem cell therapy has been emerged as an effective therapeutic approach in this area. Stem cells divided into multipotent stem cells and pluripotent stem cells. A large number studies indicated that utilization of each of them are associated with a variety of advantages and disadvantages. Multiple lines evidence indicated that stem cell therapy could be used as suitable therapeutic approach for treatment of cardiovascular diseases. Many clinical trials have been performed for assessing efficiency of stem cell therapies in human. However, stem cell therapy are associated with some challenges, but, it seems resolving of them could contribute to using of them as effective therapeutic approach for patients who suffering from cardiovascular diseases. In the current review, we summarized current therapeutic strategies based on stem cells for cardiovascular diseases. J. Cell. Biochem. 119: 95–104, 2018. © 2017 Wiley Periodicals, Inc. 相似文献
57.
Chi-Cheng Lu Jai-Sing Yang Jo-Hua Chiang Mann-Jen Hour Kuei-Li Lin Tsung-Han Lee Jing-Gung Chung 《Biochimica et Biophysica Acta (BBA)/General Subjects》2014
Background
This investigation clearly clarified the synthesized and antimitotic compound, 2-(3′-methoxyphenyl)-6-pyrrolidinyl-4-quinazolinone (HMJ-38), addressing its target and precise mechanism of action. We hypothesized that HMJ-38 might sensitize apoptotic death of human oral carcinoma CAL 27 cells in vitro and inhibit xenograft tumor growth in vivo.Methods
Cell viability was assessed utilizing MTT assay. HMJ-38-treated cells represented DNA fragmentation using agarose gel electrophoresis as further evidenced using TUNEL staining. Flow cytometric analyses, immunoblotting and quantitative RT-PCR were applied for protein and gene expression. Antitumor xenograft study was employed.Results
HMJ-38 concentration- and time-dependently reduced viability of CAL 27 cells. The effect of intrinsic molecules was signalized during HMJ-38 exposure with disruption of ΔΨm, MPT pore opening and the release of various events from mitochondria undergoing cell apoptosis. HMJ-38 also markedly facilitated G2/M phase arrest. HMJ-38 stimulated the activation of CDK1 activity that modulated phosphorylation on Ser70 of Bcl-2-mediated mitotic arrest and apoptosis. HMJ-38 triggered intracellular Ca2 + release and activated related pivotal hallmarks of ER stress. HMJ-38 in nude mice bearing CAL 27 tumor xenografts decreased tumor growth. Furthermore, HMJ-38 enhanced caspase-3 gene expression and protein level in xenotransplanted tumors.Conclusions
Early roles of mitotic arrest, unfolded protein response and mitochondria-dependent signaling contributed to apoptotic CAL 27 cell demise induced by HMJ-38. In in vivo experiments, HMJ-38 also efficaciously suppressed tumor volume in a xenotransplantation model.General significance
This finding might fully support a critical event for HMJ-38 via induction of apoptotic machinery and ER stress against human oral cancer cells. 相似文献58.
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Methylmethacrylate (MMA) is the most commonly used embedding medium for sectioning undecalcified bone; however, a number of problems exist with its use in a research laboratory. MMA requires a long infiltration time and temperature control, and it reacts with many polymers. We used Kleer Set resin™ as an alternative embedding medium for sectioning undecalcified bone specimens. Fluorochrome labeled bone specimens were sectioned transversely using a ground section technique and longitudinally on a sledge macrotome. The slides were viewed using both transmitted light and epifluorescence microscopy. High quality sections were obtained using Kleer Set resin™ for both sectioning techniques. We have shown that this new embedding medium is simpler, safer, quicker to use and does not interfere with visualization of fluorochromes. 相似文献