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941.
Yoshiteru Sasaki Soichi Sano Masaki Nakahara Shigeo Murata Kohei Kometani Yuichi Aiba Shinji Sakamoto Yoshihiro Watanabe Keiji Tanaka Tomohiro Kurosaki Kazuhiro Iwai 《The EMBO journal》2013,32(18):2463-2476
The linear ubiquitin chain assembly complex (LUBAC) plays a crucial role in activating the canonical NF‐κB pathway, which is important for B‐cell development and function. Here, we describe a mouse model (B‐HOIPΔlinear) in which the linear polyubiquitination activity of LUBAC is specifically ablated in B cells. Canonical NF‐κB and ERK activation, mediated by the tumour necrosis factor (TNF) receptor superfamily receptors CD40 and TACI, was impaired in B cells from B‐HOIPΔlinear mice due to defective activation of the IKK complex; however, B‐cell receptor (BCR)‐mediated activation of the NF‐κB and ERK pathways was unaffected. B‐HOIPΔlinear mice show impaired B1‐cell development and defective antibody responses to thymus‐dependent and thymus‐independent II antigens. Taken together, these data suggest that LUBAC‐mediated linear polyubiquitination is essential for B‐cell development and activation, possibly via canonical NF‐κB and ERK activation induced by the TNF receptor superfamily, but not by the BCR. 相似文献
942.
Yoichi Honda Toshikazu Irie Mina Atsuji Takashi Watanabe Masaaki Kuwahara 《Mycoscience》1996,37(4):459-461
To develop a dominant genetic marker inPleurotus ostreatus, mutant strains resistant to a carboxin-derived fungicide, flutolanil, were isolated. These mutants included strains which
showed resistance to 50-fold higher concentration of fluotolanil than the wild-type strain, even after successive cultivations
in the absence of the drug. Dominance of the phenotype was confirmed by back-crossing between the resistant and wild-type
monokaryons. The flutolanilresistance was also shown to be stably inherited by the basidiospore-derived progenies of the mutant
strains. 相似文献
943.
Nobuyuki Kawasaki Kazuhiro Komatsu Ayato Kohzu Noriko Tomioka Ryuichiro Shinohara Takayuki Satou Fumiko Nara Watanabe Yuya Tada Koji Hamasaki M. R. M. Kushairi Akio Imai 《Applied and environmental microbiology》2013,79(23):7160-7168
Incubation experiments using filtered waters from Lake Kasumigaura were conducted to examine bacterial contribution to a dissolved organic carbon (DOC) pool. Bacterial abundance, bacterial production, concentrations of DOC, total dissolved amino acids (TDAA), and total dissolved neutral sugars (TDNS) were monitored during the experiments. Bacterial production during the first few days was very high (20 to 35 μg C liter−1 day−1), accounting for 40 to 70% of primary production. The total bacterial production accounted for 34 to 55% of the DOC loss during the experiment, indicating high bacterial activities in Lake Kasumigaura. The DOC degradation was only 12 to 15%, whereas the degradation of TDAA and TDNS ranged from 30 to 50%, suggesting the preferential usage of TDAA and TDNS. The contribution of bacterially derived carbon to a DOC pool in Lake Kasumigaura was estimated using d-amino acids as bacterial biomarkers and accounted for 30 to 50% of the lake DOC. These values were much higher than those estimated for the open ocean (20 to 30%). The ratio of bacterially derived carbon to bulk carbon increased slightly with time, suggesting that the bacterially derived carbon is more resistant to microbial degradation than bulk carbon. This is the first study to estimate the bacterial contribution to a DOC pool in freshwater environments. These results indicate that bacteria play even more important roles in carbon cycles in freshwater environments than in open oceans and also suggests that recent increases in recalcitrant DOC in various lakes could be attributed to bacterially derived carbon. The potential differences in bacterial contributions to dissolved organic matter (DOM) between freshwater and marine environments are discussed. 相似文献
944.
Functional role of stromal interaction molecule 1 (STIM1) in vascular smooth muscle cells 总被引:2,自引:0,他引:2
Takahashi Y Watanabe H Murakami M Ono K Munehisa Y Koyama T Nobori K Iijima T Ito H 《Biochemical and biophysical research communications》2007,361(4):934-940
We investigated the functional role of STIM1, a Ca(2+) sensor in the endoplasmic reticulum (ER) that regulates store-operated Ca(2+) entry (SOCE), in vascular smooth muscle cells (VSMCs). STIM1 was mainly localized at the ER and plasma membrane. The knockdown of STIM1 expression by small interfering (si) RNA drastically decreased SOCE. In contrast, an EF-hand mutant of STIM1, STIM1(E87A), produced a marked increase in SOCE, which was abolished by co-transfection with siRNA to transient receptor potential canonical 1 (TRPC1). In addition, transfection with siRNA against STIM1 suppressed phosphorylation of cAMP-responsive element binding protein (CREB) and cell growth. These results suggest that STIM1 is an essential component of SOCE and that it is involved in VSMC proliferation. 相似文献
945.
Kanai T Tanimoto K Nemoto Y Fujii R Makita S Totsuka T Watanabe M 《American journal of physiology. Gastrointestinal and liver physiology》2006,290(5):G1051-G1058
Naturally arising CD4+CD25+ regulatory T (T(R)) cells have been shown to prevent and cure murine T cell-mediated colitis. However, their exact mechanism of controlling colitogenic memory CD4+ T cells in in vivo systems excluding the initial process of naive T cell activation and differentiation has not been examined to date. Using the colitogenic effector memory (T(EM)) CD4+ cell-mediated colitis model induced by adoptive transfer of colitogenic CD4+CD44(high)CD62L(-) lamina propria (LP) T cells obtained from colitic CD4+CD45RB(high) T cell-transferred mice, we have shown in the present study that CD4+CD25+ T(R) cells are able not only to suppress the development of colitis, Th1 cytokine production, and the expansion of colitogenic LP CD4+ T(EM) cells but also to expand these cells by themselves extensively in vivo. An in vitro coculture assay revealed that CD4+CD25+ T(R) cells proliferated in the presence of IL-2-producing colitogenic LP CD4+ T(EM) cells at the early time point (48 h after culture), followed by the acquisition of suppressive activity at the late time point (96 h after culture). Collectively, these data suggest the distinct timing of the IL-2-dependent expansion of CD4+CD25+ T(R) cells and the their suppressive activity on colitogenic LP CD4+ T(EM) cells. 相似文献
946.
T Wada K Nakagawa T Watanabe G Nishitai J Seo H Kishimoto D Kitagawa T Sasaki J M Penninger H Nishina T Katada 《The Journal of biological chemistry》2001,276(33):30892-30897
Stress-activated protein kinase/c-Jun NH(2)-terminal kinase (SAPK/JNK), which is a member of the mitogen-activated protein kinase (MAPK) family, plays an important role in a stress-induced signaling cascade. SAPK/JNK activation requires the phosphorylation of Thr and Tyr residues in its Thr-Pro-Tyr motif, and SEK1 (MKK4) and MKK7 (SEK2) have been identified as the upstream MAPK kinases. Here we examined the activation and phosphorylation sites of SAPK/JNK and differentiated the contribution of SEK1 and MKK7alpha1, -gamma1, and -gamma2 isoforms to the MAPK activation. In SEK1-deficient mouse embryonic stem cells, stress-induced SAPK/JNK activation was markedly impaired, and this defect was accompanied with a decreased level of the Tyr phosphorylation. Analysis in HeLa cells co-transfected with the two MAPK kinases revealed that the Thr and Tyr of SAPK/JNK were independently phosphorylated in response to heat shock by MKK7gamma1 and SEK1, respectively. However, MKK7alpha1 failed to phosphorylate the Thr of SAPK/JNK unless its Tyr residue was phosphorylated by SEK1. In contrast, MKK7gamma2 had the ability to phosphorylate both Thr and Tyr residues. In all cases, the dual phosphorylation of the Thr and Tyr residues was essentially required for the full activation of SAPK/JNK. These data provide the first evidence that synergistic activation of SAPK/JNK requires both phosphorylation at the Thr and Tyr residues in living cells and that the preference for the Thr and Tyr phosphorylation was different among the members of MAPK kinases. 相似文献
947.
948.
Shibata Y Kamata T Kimura M Yamashita M Wang CR Murata K Miyazaki M Taniguchi M Watanabe N Nakayama T 《Journal of immunology (Baltimore, Md. : 1950)》2002,169(4):2134-2140
The central role for Th2 cells in the development of Ag-induced airway hyperresponsiveness and eosinophilic inflammation is well documented. We have reported a crucial role for TCR-induced activation of the Ras/extracellular signal-regulated kinase mitogen-activated protein kinase cascade in Th2 cell differentiation. Here, we show that the development of both OVA-induced airway hyperresponsiveness and eosinophilic airway inflammation in a mouse asthma model are attenuated in transgenic mice by the overexpression of enzymatically inactive Ras molecules in T cells. In addition, reduced levels of IL-5 production and eosinophilic inflammation induced by nematode infection (Nippostrongylus brasiliensis or Heligmosomoides polygyrus) were detected. Thus, the level of Ras activation in T cells appears to determine Th2-dependent eosinophilic inflammation and Ag-induced airway hyperresponsiveness. 相似文献
949.
Muscarinic agonists inhibit cyclic AMP (cAMP)-induced phosphorylation of the cardiac protein phospholamban. The mechanism of this muscarinic inhibition of phosphorylation of phospholamban appears to occur at more than one level in the series of reactions comprising the adenylate cyclase, cAMP-dependent protein kinase system. Muscarinic agonists attenuate hormone and drug stimulation of cardiac adenylate cyclase. This results in reduced tissue levels of cAMP and diminished phosphorylation of cardiac proteins and consequent inhibition of biochemical and inotropic effects of drugs that act via cAMP. The mechanism of muscarinic inhibition of adenylate cyclase is only partially understood, but probably involves the inhibitory guanine nucleotide-binding regulatory protein. In addition to the inhibition of adenylate cyclase, muscarinic agonists appear to be able to inhibit the effects of cAMP. The mechanism for this second effect of muscarinic agonists is unknown. 相似文献
950.
Yamazaki Masaaki; Ono Ayako; Watanabe Koji; Sasaki Kuniaki; Tashiro Hiroyuki; Nomura Toru 《DNA research》1995,2(4):187-189
Most ofthe human Not I linking clones identified to date areconsidered to be derived from CpG islands because ofthe recognitionsequence of this enzyme, and CpG islands have been reportedto be located around the 5' regions of genes. As a pilot study,we determined the complete nucleotide sequence (41,924 bp) ofa human cosmid clone (LL21NC02Q7A10) containing the marker D21S246originating from a Not I linking clone. As a result of sequenceanalysis, we successfully mapped and revealed the genomic genestructure for KIAA0002 previously reported as a cDNA clone.This gene consists of 15 exons and was shown to exist at theD21S246 locus on human chromosome 21q21.3q22.1. Theseresults demonstrated that genomic marker-anchored DNA sequencingis a useful approach for the human genome project. 相似文献