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121.
Suzuki T Das SK Inoue H Kazami M Hino O Kobayashi T Yeung RS Kobayashi K Tadokoro T Yamamoto Y 《Biochemical and biophysical research communications》2008,368(1):132-137
The products of the TSC1 (hamartin) and TCS2 (tuberin) tumor suppressor genes negatively regulate cell growth by inhibiting mTOR signaling. Recent research has led to the postulation that tuberin and/or hamartin are involved in tumor migration, presumably through Rho activation. Here we show that LEF-8 cells, which contain a Y1571 missense mutation in tuberin, express higher Rac1 activity than tuberin negative and positive cells. We also provide evidence of obvious lamellipodia formation in LEF-8 cells. Since the production of TSC2Y1571H cannot form a hetero-complex with hamartin, we further analyzed another mutant, TSC2R611Q, which also lacks the ability to form a complex with hamartin. Introducing both forms of mutated TSC2 into COS-1 cells increased Rac1 activity as well as cell motility. We also found these two mutants interacted with Rac1. We further demonstrated that the introduction of mutated TSC2 into COS-1 cells can generate higher reactive oxygen species (ROS). These results indicate that loss-of-function mutated tuberin can activate Rac1 and thereby increase ROS production. 相似文献
122.
Atsuhiro Nabei Takayoshi Kuroda-Sowa Takashi Okubo Masahiko Maekawa Megumu Munakata 《Inorganica chimica acta》2008,361(12-13):3489-3493
Two new one-dimensional Fe(II)-bis-Schiff base complexes, [Fe(L1)(pyz)] · CH2Cl2 (1) and [Fe(L2)(pyz)] · 2CH2Cl2 (2) (H2L1 = bis(O-vanillin)-O-phenylenediimine, H2L2 = bis(O-vanillin)-2,3-naphthalenediimine, pyz = pyrazine) are reported with their crystal structures and magnetic property. Compound 1 shows a two-step SCO behavior while 2 shows HS at all the temperature range measured. Although the extension of aromatic moiety from benzene (L1) to naphthalene (L2) was introduced for the purpose of strengthening the cooperativity, it leads to the absence of SCO, due to the unanticipated π–π interaction, which leads to the longer Fe–N bond lengths and a weak ligand field around Fe(II) ion. 相似文献
123.
When immersed in water at 50-60 degrees, mature soybean seeds release a large amount of protein. The major protein released was basic 7S globulin (Bg), which is present in the cotyledons of soybean seeds. The released Bg consisted of the 27,000 and 16,000 subunits which were linked by disulphide bonding and glycosylated. The released Bg exhibited an identical structure with the mature Bg which was synthesized in the normal developing seeds. Proteins like Bg were also found to be released into hot water from the seeds of legume species such as azuki-bean, cowpea, mung-bean and winged-bean. Besides Bg and Bg-like proteins, a few proteins including the 9,000 hydrophobic protein in soybean, ubiquitin in cowpea and mung-bean, and Kunitz trypsin inhibitor in winged-bean, were released from the seeds in hot water. 相似文献
124.
Aoki K Uchiyama R Yamauchi S Katayama T Itonori S Sugita M Hada N Yamada-Hada J Takeda T Kumagai H Yamamoto K 《The Journal of biological chemistry》2004,279(31):32028-32034
We found for the first time that Zygomycetes species showed resistance to Aureobasidin A, an antifungal agent. A novel family of neutral glycosphingolipids (GSLs) was found in these fungi and isolated from Mucor hiemalis, which is a typical Zygomycetes species. Their structures were completely determined by compositional sugar, fatty acid, and sphingoid analyses, methylation analysis, matrix-assisted laser desorption ionization time-of-flight/mass spectrometry, and (1)H NMR spectroscopy. They were as follows: Gal beta 1-6Gal beta 1-1Cer (CDS), Gal alpha 1-6Gal beta 1-6Gal beta 1-1Cer (CTS), Gal alpha 1-6Gal alpha 1-6Gal beta 1-6Gal beta 1-1Cer (CTeS), and Gal alpha 1-6Gal alpha 1-6Gal alpha 1-6Gal beta 1-6Gal beta 1-1Cer (CPS). The ceramide moieties of these GSLs consist of 24:0, 25:0, and 26:0 2-hydroxy acids as major fatty acids and 4-hydroxyoctadecasphinganine (phytosphingosine) as the sole sphingoid. However, the glycosylinositolphosphoceramide families that are the major GSLs components in fungi were not detected in Zygomycetes at all. This seems to be the reason that Aureobasidin A is not effective for Zygomycetes as an antifungal agent. Our results indicate that the biosynthetic pathway for GSLs in Zygomycetes is significantly different from those in other fungi and suggest that any inhibitor of this pathway may be effective for mucormycosis, which is a serious pathogenic disease for humans. 相似文献
125.
Takemitsu Mizunaga Tadahiro Oshida Akiko Takasaki Yoshiharu Maruyama 《Bioscience, biotechnology, and biochemistry》2013,77(6):1445-1450
To find the function of the mannan chains covalently attached to yeast repressible acid phosphatase, the N-glycosidic carbohydrate chains were removed by endo-β-N-acetyl-glucosaminidase H under native conditions. Almost all of the N-glycosidic mannan chains were cleaved off by the glycosidase. The deglycosylated enzyme was shown to be a dimer structure as is the native enzyme. The deglycosylated enzyme retained enzyme activity, the same Km, and the same circular dichroism spectra as the native enzyme. These results indicate that the carbohydrate chains are not essential for maintaining the active enzyme structure, but the deglycosylated enzyme was shown to be more sensitive to acidic pH and high temperature. 相似文献
126.
We examined gametogenesis and the periodicity of planula release in the brooding coral Acropora (Isopora) brueggemanni (Brook, 1893) on Akajima Island, Okinawa, Japan. We captured the moment when A. brueggemanni would be in the process of self-fertilization. Whole colonies of this species were cultured separately or together with other colonies in plastic containers. We observed no apparent periodicity of planula release in the collected colonies. A few planulae were released intermittently during the observation period, regardless of whether the colonies were cultured individually or with other colonies. Serial paraffin sections of A. brueggemanni showed follicle-like cells surrounding the oocyte during vitellogenesis. In September and October, some spermaries looked half-broken and some ova were surrounded by sperm or spermaries instead of follicle-like cells. Such ova were heart-shaped and may have been cells at the first cleavage stage. These observations suggest that the migration of spermaries and/or oocytes resulted in the close proximity of oocytes and sperm, which would allow self-fertilization. This possibility, together with the production of planula larvae by isolated colonies, suggests that this brooding coral engages in self-fertilization. 相似文献
127.
Embryogenesis in the reef building corals Acropora intermedia, A. solitaryensis, A. hyacinthus, A. digitifera, and A. tenuis was studied in detail at the morphological level, and the relationships among the animal pole, blastopore, and mouth were investigated for the first time in corals. These species showed essentially the same sequence of development. The embryo undergoes spiral-like holoblastic cleavage despite the presence of a dense isolecithal yolk. After the morula stage, the embryo enters the "prawn-chip" stage, which consists of an irregularly shaped cellular bilayer. The embryo begins to roll inward to form the bowl stage; the round shape observed during this stage suggests that it may be the beginning of gastrulation. However, the blastopore closes and the stomodeum (mouth and pharynx) is formed via invagination at a site near the closed blastopore. During the planula stage, a concavity forms in the aboral region in conjunction with numerous spirocysts, suggesting that spirocysts are used to attach to the substrate before the onset of metamorphosis. 相似文献
128.
Masato Aoyama Hiroshi Dohi Shigeru Shioya Yukari Takeuchi Yuji Mori Tadakatu Okubo 《Applied animal behaviour science》1994,40(3-4)
A feeding-deterrent substance was isolated from cattle feces and its effects on ingestive behavior were examined in goats. The substance was added to alfalfa hay and presented to the goats in the following experiments. In a two-choice test, between control fodder and the fodder treated with the substance, animals avoided eating treated fodder. This food-deterrent effect was strengthened in a dose-dependent manner. The results of ingestive behavior analysis suggested that this substance affected the goats through olfaction. However, in a single-presentation test, where the goats had no choice, no effect on ingestive behavior was noticed. It is therefore suggested that the preference induced by the substance is relative rather than absolute in the ingestive behavior of goats. 相似文献
129.
S Shimura T Okubo S Maeda T Aoki M Tomioka Y Shindo T Takishima K Umeya 《Biorheology》1983,20(5):677-683
We studied the effects of expectorants (mucolytic agents) in vivo on the relaxation behavior of sputum viscoelasticity. Seven female and thirty-three male patients (56.8 +/- 19.3 yrs, range: 21 to 82 years old) with a chronic pulmonary disease except bronchial asthma were studied. They were randomly put into the control group or a group which would be given oral treatments with an expectorant for a week after a one week washout period. The groups were as follows: Group I (n = 8), control; Group II (n = 7), Bromhexine hydrochloride 24 mg per day; Group III (n = 10), Ambroxol 90 mg per day; Group IV (n = 9) alpha - Chymotrypsin buccle 100 ch.u. per day; Group V (n = 6), Serratiopeptidase 30 mg per day. In Groups IV & V, frequency dependence of sputum viscoelasticity at the range of omega = 10(-3) to 10(0) rad.sec-1 were clearly changed after the treatments, and the magnitude of the relaxation and its main relaxation time were significantly increased. On the other hand, in Groups I, II & III, no significant changes of the frequency dependences were observed. These findings suggest that proteolytic enzymes administered orally work on the molecular structure of sputum, and break down their linkages between subunits of the structure. 相似文献
130.