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991.
992.
Soon-Yong Choi Hee Yun Park Aron Paek Gil Seob Kim Seong Eun Jeong 《Molecules and cells》2009,28(6):575-581
Ornithine decarboxylase (ODC) is a rate-limiting enzyme in the biosynthesis of polyamines, which are essential for cell growth,
differentiation, and proliferation. This report presents the characterization of an ODC-encoding cDNA (SlitODC) isolated from
a moth species, the tobacco cutworm, Spodoptera litura (Lepidoptera); its expression in a polyamine-deficient strain of yeast, S. cerevisiae; and the recovery in polyamine levels and proliferation rate with the introduction of the insect enzyme. SlitODC encodes 448 amino acid residues, 4 amino acids longer than B. Mori ODC that has 71% identity, and has a longer C-terminus, consistent with B. mori ODC, than the reported dipteran enzymes. The null mutant yeast strain in the ODC gene, SPE1, showed remarkably depleted polyamine levels; in putrescine, spermidine, and spermine, the levels were > 7, > 1, and > 4%,
respectively, of the levels in the wild-type strain. This consequently caused a significant arrest in cell proliferation of
> 4% of the wild-type strain in polyaminefree media. The transformed strain, with the substituted SlitODC for the deleted endogenous ODC, grew and proliferated rapidly at even a higher rate than the wild-type strain. Furthermore,
its polyamine content was significantly higher than even that in the wild-type strain as well as the spe1-null mutant, particularly with a very continuously enhanced putrescine level, reflecting no inhibition mechanism operating
in the putrescine synthesis step by any corresponding insect ODC antizymes to SlitODC in this yeast system. 相似文献
993.
Man Il Kim Jee Yeon Baek Min Jee Kim Heon Cheon Jeong Ki-Gyoung Kim Chang Hwan Bae Yeon Soo Han Byung Rae Jin Iksoo Kim 《Molecules and cells》2009,28(4):347-363
The 15,389-bp long complete mitogenome of the endangered red-spotted apollo butterfly, Parnassius bremeri (Lepidoptera: Papilionidae) was determined in this study. The start codon for the COI gene in insects has been extensively discussed, and has long remained a matter of some controversy. Herein, we propose that the CGA (arginine) sequence functions as the start codon for the COI gene in lepidopteran insects, on the basis of complete mitogenome sequences of lepidopteran insects, including P. bremeri, as well as additional sequences of the COI start region from a diverse taxonomic range of lepidopteran species (a total of 53 species from 15 families). In our extensive search for a tRNA-like structure in the A+T-rich region, one tRNATrp-like sequence and one tRNALeu (UUR)-like sequence were detected in the P. bremeri A+T-rich region, and one or more tRNA-like structures were detected in the A+T-rich region of the majority of other sequenced lepidopteran insects, thereby indicating that such features occur frequently in the lepidopteran mitogenomes. Phylogenetic analysis using the concatenated 13 amino acid sequences and nucleotide sequences of PCGs of the four macrolepidopteran superfamilies together with the Tortricoidea and Pyraloidea resulted in the successful recovery of a monophyly of Papilionoidea and a monophyly of Bombycoidea. However, the Geometroidea were unexpectedly identified as a sister group of the Bombycoidea, rather than the Papilionoidea. 相似文献
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998.
Dephosphorylation of the C-terminal Tyrosyl Residue of the DNA Damage-related Histone H2A.X Is Mediated by the Protein Phosphatase Eyes Absent 总被引:1,自引:0,他引:1
999.
1000.
Won Jun Choi Hyuk Woo Lee Hea Ok Kim Moshe Chinn Zhan-Guo Gao Amit Patel Kenneth A. Jacobson Hyung Ryong Moon Young Hoon Jung Lak Shin Jeong 《Bioorganic & medicinal chemistry》2009,17(23):8003-8011
On the basis of a bioisosteric rationale, 4′-thionucleoside analogues of IB-MECA (N6-(3-Iodo-benzyl)-9-(5′-methylaminocarbonyl-β-d-ribofuranosyl)adenine), which is a potent and selective A3 adenosine receptor (AR) agonist, were synthesized from d-gulonic acid γ-lactone. The 4′-thio analogue (5h) of IB-MECA showed extremely high binding affinity (Ki = 0.25 nM) at the human A3AR and was more potent than IB-MECA (Ki = 1.4 nM). Bulky substituents at the 5′-uronamide position, such as cyclohexyl and 2-methylbenzyl, in this series of 2-H nucleoside derivatives were tolerated in A3AR binding, although small alkyl analogues were more potent. 相似文献