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31.
Hyojin Park Sungwoon Lee Pravesh Shrestha Jihye Kim Jeong Ae Park Yeongrim Ko Young Ho Ban Dae-Young Park Sang-Jun Ha Gou Young Koh Victor Sukbong Hong Naoki Mochizuki Young-Myeong Kim Weontae Lee Young-Guen Kwon 《The Journal of cell biology》2015,211(3):619-637
The phosphoinositide 3-kinase–Akt signaling pathway is essential to many biological processes, including cell proliferation, survival, metabolism, and angiogenesis, under pathophysiological conditions. Although 3-phosphoinositide–dependent kinase 1 (PDK1) is a primary activator of Akt at the plasma membrane, the optimal activation mechanism remains unclear. We report that adhesion molecule with IgG-like domain 2 (AMIGO2) is a novel scaffold protein that regulates PDK1 membrane localization and Akt activation. Loss of AMIGO2 in endothelial cells (ECs) led to apoptosis and inhibition of angiogenesis with Akt inactivation. Amino acid residues 465–474 in AMIGO2 directly bind to the PDK1 pleckstrin homology domain. A synthetic peptide containing the AMIGO2 465–474 residues abrogated the AMIGO2–PDK1 interaction and Akt activation. Moreover, it effectively suppressed pathological angiogenesis in murine tumor and oxygen-induced retinopathy models. These results demonstrate that AMIGO2 is an important regulator of the PDK1–Akt pathway in ECs and suggest that interference of the PDK1–AMIGO2 interaction might be a novel pharmaceutical target for designing an Akt pathway inhibitor. 相似文献
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Keiichi Okada Takami Satomura Akihiko Kinoshita Takao Horikoshi Koh Yasue Masaki Fukuda Akiyoshi Yamada 《Mycoscience》2011,52(1):59-64
In this study, two plots in a secondary and another two in planted Pinus densiflora stands were exposed to different forest treatments, and the ectomycorrhizal (EM) biomass and its ergosterol content was measured
for a year. The unmanaged plot in the secondary stand had greater EM biomass than those in any other plots. Whereas understory
cutting had less effect on EM biomass, litter and humus removal decreased pine EM biomass and its ergosterol content, suggesting
that such forest treatment alters EM biomass and its structure. 相似文献
36.
Keiichi Okada Sachiko Okada Koh Yasue Masaki Fukuda Akiyoshi Yamada 《Ecological Research》2011,26(2):411-419
Ectomycorrhizas (EM) are among the most active components of forest soil biomass because they represent the dominant soil
carbon efflux from forests. However, temporal patterns of EM biomass in relation to climatic factors and host tree growth
remain unclear. We sampled EM and fine roots of pine each month for 6 years (May 2003 to June 2009) in a 40–50-year-old Pinus densiflora forest in Japan. Tree ring width of host pines in the plot was measured to assess the chronological sequence of annual tree
growth. EM biomass was not stable during the 6 years of monitoring and seasonal patterns were indistinct. Multiple correlation
analyses revealed that the autumn precipitation in the previous year was the most determinative factor of EM biomass in the
current year, with a negative correlation. In contrast, tree ring width generally showed a stable annual growth pattern throughout
the monitoring period. Clarification of such a carbon allocation pattern is important in understanding forest carbon dynamics
under a temperate monsoon climate. 相似文献
37.
Myung-Soon Yang Jin-Su Hong Seong-Tae Kim Ki-Young Lee Kye Won Park Suk-Tae Kwon Dae-Hyuk Kweon Young Ho Koh Nicholas Gaiano Keejung Yoon 《Biochemical and biophysical research communications》2011,(1):133
Notch signaling pathway enhances neural stem cell characters and regulates cell fate decisions during neural development. Interestingly, besides Notch, other γ-secretase substrates such as APP, LRP2, and ErbB4 have also proven to have biological functions in neural development. We designed a unique experimental setting, combining gain-of- (expression of Notch intracellular domain, NICD) and loss-of-function (γ-secretase inhibition) methods, and were able to examine the function of Notch alone by excluding the activity of other γ-secretase substrates. Here, we show that the frequency and size of neurospheres generated from embryonic neural stem cells (NSCs) significantly decreased by 62.7% and 37.2%, respectively, in the presence of γ-secretase inhibitor even when NICD was expressed. Under the condition of differentiation, however, the γ-secretase inhibitor treatment did not influence the promotion of astrogenesis at the expense of neurogenesis by NICD. These results indicate that other γ-secretase substrate(s) along with Notch are important in the maintenance of the stemness of NSCs, but that Notch alone can sufficiently inhibit neurogenesis without the action of the other γ-secretase substrates during differentiation. 相似文献
38.
Fine mapping and candidate gene analysis of dense and erect panicle 3, DEP3, which confers high grain yield in rice (Oryza sativa L.) 总被引:1,自引:0,他引:1
Qiao Y Piao R Shi J Lee SI Jiang W Kim BK Lee J Han L Ma W Koh HJ 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2011,122(7):1439-1449
Architecture of the rice inflorescence, which is determined mainly by the morphology, number and length of primary and secondary inflorescence branches, is an important agronomical trait. In the current study, we characterized a novel dense and erect panicle (EP) mutant, dep3, derived from the Oryza sativa ssp. japonica cultivar Hwacheong treated with N-methyl-N-nitrosourea. The panicle of the dep3 mutant remained erect from flowering to full maturation, whereas the panicle of the wild type plant began to droop after flowering. The dep3 mutation also regulated other panicle characteristics, including panicle length, grain shape and grain number per panicle. Anatomical observations revealed that the dep3 mutant had more small vascular bundles and a thicker culm than wild type plants, explaining the EP phenotype. Genetic analysis indicated that the phenotype with the dense and EP was controlled by a single recessive gene, termed dep3. The DEP3 gene was identified as the candidate via a map-based cloning approach and was predicted to encode a patatin-like phospholipase A2 (PLA2) superfamily domain-containing protein. The mutant allele gene carried a 408?bp genomic deletion within LOC_Os06g46350, which included the last 47?bp coding region of the third exon and the first 361?bp of the 3??-untranslated region. Taken together, our results indicated that the patatin-like PLA2 might play a significant role in the formation of vascular bundles, and that the dep3 mutant may provide another EP resource for rice breeding programs. 相似文献
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