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891.
Tamura A Nino H Minobe T Raneva VG Shigematsu N Hara H Kishida T Ebihara K 《Bioscience, biotechnology, and biochemistry》2006,70(6):1416-1422
We evaluated the body energy accumulation as fat and protein from ingestion of difructose anhydride III (DFAIII). Male Wistar rats were fed 0, 0.25, 0.5, 1.0, or 1.5 g per d of sucrose or DFAIII added to a 7 g of basal diet for 20 d. Supplements of DFAIII did not increase whole body or peripheral fat or total body energy, whereas sucrose increased them in a dose-dependent manner. Dose-dependent increases in body water were observed in both groups. The body protein was influenced by the dose of sugars. The estimated available energy value of DFAIII was 0.263 kcal per gram; this value is one-fifteenth that of sucrose. Ingestion of DFAIII dose-dependently increased the cecal SCFA pool. DFAIII was not detected in feces, showing complete degradation of DFAIII in the intestine. These results indicate that DFAIII is a fermentable saccharide with quite low available energy for fat accumulation. 相似文献
892.
Takahashi H Miyazawa M Ina Y Fukunishi Y Mizukoshi Y Nakamura H Shimada I 《Journal of biomolecular NMR》2006,34(3):167-177
Cross-saturation experiments allow the identification of the contact residues of large protein complexes (MW>50 K) more rigorously
than conventional NMR approaches which involve chemical shift perturbations and hydrogen-deuterium exchange experiments [Takahashi
et al. (2000) Nat. Struct. Biol., 7, 220–223]. In the amide proton-based cross-saturation experiment, the combined use of high deuteration levels for non-exchangeable
protons of the ligand protein and a solvent with a low concentration of
1H2O
greatly enhanced the selectivity of the intermolecular cross-saturation phenomenon. Unfortunately, experimental limitations
caused losses in sensitivity. Furthermore, since main chain amide protons are not generally exposed to solvent, the efficiency
of the saturation transfer directed to the main chain amide protons is not very high. Here we propose an alternative cross-saturation
experiment which utilizes the methyl protons of the side chains of the ligand protein. Owing to the fast internal rotation
along the methyl axis, we theoretically and experimentally demonstrated the enhanced efficiency of this approach. The methyl-utilizing
cross-saturation experiment has clear advantages in sensitivity and saturation transfer efficiency over the amide proton-based
approach.
Electronic supplementary material Electronic supplementary material is available for this article at
and accessible for authorised users. 相似文献
893.
In this study, we describe a method of simultaneous conditional gene silencing of up to four genes in Escherichia coli by using antisense RNAs. We used antisense RNAs with paired termini, which carried flanking inverted repeats to create paired double-stranded RNA termini; these RNAs have been proven to have high silencing efficacy. To express antisense RNAs, we constructed four IPTG-inducible vectors carrying different but compatible replication origins. When the lacZ antisense RNA was expressed using these vectors, lacZ expression was successfully silenced by all the vectors, but the expression level of the antisense RNA and silencing efficacy differed depending on the used vectors. All the vectors were co-transformable; the antisense RNAs against lacZ, ackA, pta and pepN were co-expressed, and silencing of all the target genes was confirmed. Furthermore, when antisense RNAs were targeted to the mutator genes mutS, mutD (dnaQ) and ndk, which are involved in DNA replication or DNA mismatch repair, spontaneous mutation frequencies increased over 2000-fold. The resulting mutator strain is useful for random mutagenesis of plasmids. The method provides a robust tool for investigating functional relationships between multiple genes or altering cell phenotypes for biotechnological and industrial applications. 相似文献
894.
Yoshifumi Yamawaki Yoshihiro Toh 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》2009,195(3):253-264
Responses to visual stimuli of some neurons that descend the nerve cord from the brain were recorded extracellularly in the
mantis Tenodera aridifolia. Most of the recorded neurons showed their largest responses to looming stimuli that simulated a black circle approaching
towards the mantis. The neurons showed a transient excitatory response to a gradually darkening or receding circle. The neurons
showed sustained excitation to the linearly expanding stimuli, but the spike frequency decreased rapidly. The responses of
the neurons were affected by both the diameter and the speed of looming stimuli. Faster or smaller looming stimuli elicited
a higher peak frequency. These responses were observed in both recordings from the connective between suboesophageal and prothoracic
ganglia and the connective between prothoracic and mesothoracic ganglia. There was a one-to-one correspondence of spike firing
between these two recordings with a fixed delay. The neurons had the receptive field on ipsilateral side to its axon at the
cervical connective. These results suggest that there is a looming-sensitive descending neuron, with an axon projecting over
prothoracic ganglion, in the mantis nervous system. 相似文献
895.
Barbara Kludkiewicz Yoko Takasu Robert Fedic Toshiki Tamura Frantisek Sehnal Michal Zurovec 《Insect biochemistry and molecular biology》2009,39(12):938-946
Sericins are soluble silk components encoded in Bombyx mori by three genes, of which Ser1 and Ser3 have been characterized. The Ser1 and Ser3 proteins were shown to appear later in the last larval instar as the major sericins of cocoon silk. These proteins are, however, virtually absent in the highly adhesive silk spun prior to cocoon spinning, when the larvae construct a loose scaffold for cocoon attachment. We show here that the silk-gland lumen of the feeding last instar larvae contains two abundant adhesive proteins of 230 kDa and 120 kDa that were identified as products of the Ser2 gene. We also describe the sequence, exon–intron structure, alternative splicing and deduced translation products of this gene in the Daizo p50 strain of B. mori. Two mRNAs of 5.7 and 3.1 kb are generated by alternative splicing of the largest exon. The predicted mature proteins contain 1740 and 882 amino acid residues. The repetitive amino acid sequence encoded by exons 9a and 9b is apparently responsible for the adhesiveness of Ser2 products. It has a similar periodic arrangement of motifs containing lysine and proline as a highly adhesive protein of the mussel Mytilus edulis. 相似文献
896.
Mutsumi Fukuda Seiji Watanabe Jun Kaneko Yoshifumi Itoh Yoshiyuki Kamio 《Journal of bacteriology》2009,191(5):1641-1649
897.
898.
Yoshifumi Inoue Lucie Canaff Geoffrey N. Hendy Itoko Hisa Toshitsugu Sugimoto Kazuo Chihara Hiroshi Kaji 《Journal of cellular biochemistry》2009,108(1):285-294
Parathyroid hormone (PTH) exerts an anabolic action on bone but the mechanisms are incompletely understood. We showed previously that PTH interacts with the canonical Wnt‐β‐catenin signaling pathway via the transforming growth factor (TGF)‐β signaling molecule, Smad3, to modulate osteoblast differentiation and apoptosis. Here, we examined which actions of Smad3 are TGF‐β‐independent in stimulating the osteoblast phenotype and PTH‐induced Wnt‐β‐catenin signaling. For this, the TGF‐β receptor type 1 [activin receptor‐like kinase (ALK5)] inhibitor (SB431542), and a Smad3 mutant in which the site normally phosphorylated by ALK5 is mutated from SSVS to AAVA, was used. PTH induced total β‐catenin and reduced phosphorylated β‐catenin levels at 1, 6, and 24 h in mouse osteoblastic MC3T3‐E1 cells. Transient transfection of Smad3AAVA inhibited the PTH induction of total β‐catenin and reduction of phosphorylated β‐catenin levels at 6 and 24 h, but not at 1 h, indicating that the early effects occur independently of TGF‐β receptor signaling. On the other hand, MC3T3‐E1 cell clones in which Smad3AAVA was stably expressed demonstrated elevated β‐catenin levels, although alkaline phosphatase (ALP) activity and mineralization were unaltered. In contrast, MC3T3‐E1 cell clones in which wild‐type Smad3 was stably expressed exhibited increased ALP activity and mineralization that were decreased by the ALK5 inhibitor, SB431542, although the β‐catenin levels induced in these cells were not modulated. In conclusion, the present study indicates that PTH induces osteoblast β‐catenin levels via Smad3 independently of, and dependently on, TGF‐β in the early and later induction phases, respectively. J. Cell. Biochem. 108: 285–294, 2009. © 2009 Wiley‐Liss, Inc. 相似文献
899.
Tomoko Tamura Masaharu Kuroda Tetsuo Oikawa Junko Kyozuka Kaede Terauchi Yoshiro Ishimaru Keiko Abe Tomiko Asakura 《Plant cell reports》2009,28(11):1615-1621
Signal peptide peptidase (SPP) is a multi-transmembrane aspartic proteinase involved in regulated intramembrane proteolysis,
which is implicated in fundamental life processes such as immunological response, cell signaling, tissue differentiation,
and embryogenesis. In this study, we identified two rice SPPs: OsSPP1 and OsSPP2. Green fluorescent protein-fused OsSPP1 and
OsSPP2 were localized to the ER in cultured plant cells. In situ hybridization showed that OsSPPs were strongly expressed
in vegetative shoot apex, young panicle, developing panicle, and the early developing florets. Undifferentiated cells, which
have the potential to differentiate into all of the aerial parts of the plant are presented in the shoot apex. OsSPPs are
located in both the undifferentiated cells, and the early differentiated cells at the shoot apex. These results suggest that
rice SPPs have an important function in differentiation and development at the shoot apex. The expression of the shoot apex
and ER localization is equal to dicot Arabidopsis thaliana, and will have common crucial roles in plant. 相似文献
900.
Mizuho Tamura Reiko Aizawa Masatoshi Hori Hiroshi Ozaki 《Histochemistry and cell biology》2009,131(4):483-490
Adenine phosphoribosyltransferase deficiency in mice or an excessive oral intake of adenine leads to the accumulation of 2,8-dihydroxyadenine
(DHA) in renal tubules and that causes progressive renal dysfunction accompanied by interstitial fibrosis. However, the precise
mechanism responsible for DHA-induced progressive fibrosis is not fully understood. The present study investigates the possible
involvement of monocytes/macrophages in the progressive fibrosis induced by feeding adenine to mice. Urinary calculi were
deposited in tubules on day 7 after the initiation of adenine feeding. Elevation of the serum creatinine level and loss of
body weight were observed in a time-dependent manner, suggesting the development of typical renal dysfunction induced by the
adenine feeding. In renal tissue, mRNA expression of MCP-1, MIP-1α, RANTES, IL-1β, CCR2, TGF-β, α-smooth muscle actin (α-SMA)
and collagen 1a1 was increased in parallel. Along with the increased expression of these genes, a remarkable infiltration
of macrophages into the tubulointerstitial area was observed in a time-dependent manner. In addition, in the tubulointerstitial
area, α-SMA positive fibroblasts were increased in parallel with collagen deposition. These results suggest that the excessive
consumption of adenine leads to progressive renal dysfunction in mice. We speculate that the accumulation of DHA in tubules
might stimulate epithelium to produce MCP-1 and that profibrogenic TGF-β produced by infiltrated macrophages might stimulate
interstitial fibroblasts to produce collagen. These results indicate that macrophage infiltration is one of the triggers that
initiates interstitial fibroblast activation and collagen deposition followed by renal dysfunction. 相似文献