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931.
932.
Anthony Wynshaw-Boris Tiziano Pramparo Yong Ha Youn Shinji Hirotsune 《Seminars in cell & developmental biology》2010,21(8):823-830
Lissencephaly is a severe human neuronal migration defect characterized by a smooth cerebral surface, mental retardation and seizures. The two most common genes mutated in patients with lissencephaly are LIS1 and DCX. LIS1 was the first gene cloned that was important for neuronal migration in any organism, and heterozygous mutations or deletions of LIS1 are found in the majority of patients with lissencephaly, while DCX mutations were found in males with X-linked lissencephaly. In this review, we will discuss how an understanding of the molecular and cellular pathways disrupted in model organisms with Lis1 and Dcx mutations or knock-down not only provide insights into the normal processes of neuronal migration, including neurogenesis, but they also may lead to potential novel therapeutic strategies for these severe cortical malformations. 相似文献
933.
934.
Park IS Park JU Seo MJ Kim MJ Lee HH Kim SR Kang BW Choi YH Joo WH Jeong YK 《Journal of microbiology (Seoul, Korea)》2010,48(6):836-841
A fibrinolytic enzyme of the mushroom, Schizophyllum commune was purified with chromatographic methods, including a DEAE-Sephadex A-50 ion-exchange column and gel filtrations with Sephadex
G-75 and Sephadex G-50 columns. The analysis of fibrin-zymography and SDS-PAGE showed that the enzyme was a monomeric subunit
that was estimated to be approximately 17 kDa in size. The fibrinolytic activity of the enzyme in plasminogen-rich and plasminogen-free
fibrin plates was 1.25 and 0.44 U/ml, respectively. The N-terminal amino acid sequence of the purified enzyme was identified
as HYNIXNSWSSFID, which was highly distinguished from known fibrinolytic enzymes. The relative activity of the purified enzyme
with an addition of 5 mM EDTA, Phosphoramidon, and Bestatin was about 76, 64, and 52%, respectively, indicating that it is
a metalloprotease. The optimum temperature for the purified enzyme was approximately 45°C, and over 87% of the enzymatic activity
was maintained as a stable state in a pH range from 4.0 to 6.0. Therefore, our results suggest that the potential thrombolytic
agent from S. commune is a unique type of fibrinolytic enzyme. 相似文献
935.
Selvaraj T Kim SK Kim YH Jeong YS Kim YJ Phuong ND Jung KH Kim J Yun HD Kim H 《Journal of microbiology (Seoul, Korea)》2010,48(6):856-861
A non-cellulosomal xylanase from Clostridium thermocellum, XynX, consists of a family-22 carbohydratebinding module (CBM22), a family-10 glycoside hydrolase (GH10) catalytic module, two family-9 carbohydrate-binding modules (CBM9-I and CBM9-II), and an S-layer homology (SLH) module. E. coli BL21(DE3) (pKM29), a transformant carrying xynX', produced several truncated forms of the enzyme. Among them, three major active species were purified by SDS-PAGE, activity staining, gel-slicing, and diffusion from the gel. The truncated xylanases were different from each other only in their C-terminal regions. In addition to the CBM22 and GH10 catalytic modules, XynX(1) had the CBM9-I and most of the CBM9-II, XynX(2) had the CBM9-I and about 40% of the CBM9-II, and XynX(3) had about 75% of the CBM9-I. The truncated xylanases showed higher binding capacities toward Avicel than those toward insoluble xylan. XynX(1) showed a higher affinity toward Avicel (70.5%) than XynX(2) (46.0%) and XynX(3) (42.1%); however, there were no significant differences in the affinities toward insoluble xylan. It is suggested that the CBM9 repeat, especially CBM9-II, of XynX plays a role in xylan degradation in nature by strengthening cellulose binding rather than by enhancing xylan binding. 相似文献
936.
Microbial communities in hot pepper (Capsicum annuum L.) cultivation fields under different cultivation methods were investigated by terminal restriction fragment length polymorphism
(T-RFLP) analysis. Rhizosphere soil and leaf samples were collected from control, conventional and nature-friendly cultivation
fields between May and July, 2009. Two Bacillus subtilis strains were applied to nature-friendly cultivation fields as biocontrol agents during the sampling period. Relative abundances
of bacteria and plant pathogenic fungi related T-RFs were also measured to monitor the effect of biocontrol agents on potential
plant pathogenic fungi. In the principal component analysis (PCA) based on T-RFLP profiles, the microbial communities from
rhizosphere soil samples in July, including bacteria and fungi, showed distinct difference between nature-friendly cultivation
fields and other cultivation fields. However, there was no correlation between cultivation methods and leaf microbial communities
at any sampling period. Changes in the abundance of bacteria related T-RF in the rhizosphere of nature-friendly cultivation
fields were observed clearly two months after application of biocontrol agent, while the abundance of plant pathogenic fungi
related T-RFs significantly decreased. 相似文献
937.
Jae J. Song Joo-Hang Kim Bo K. Sun Marco A. Alcala David L. Bartlett Yong J. Lee 《Cellular signalling》2010,22(3):377-385
We have previously observed that TRAIL (tumor necrosis factor-related apoptosis-inducing ligand) induces acquired TRAIL resistance by increasing Akt phosphorylation and Bcl-xL expression. In this study, we report that Src, c-Cbl, and PI3K are involved in the phosphorylation of Akt during TRAIL treatment. Data from immunoprecipitation and immunoblotting assay reveal that Src interacts with c-Cbl and PI3K. Data from immune complex kinase assay demonstrate that Src can directly phosphorylate c-Cbl and PI3K p85 subunit protein. Data from gene knockdown experiments with an RNA interference (RNAi) technique show that c-Cbl is involved in the interaction between Src and PI3K p85 during TRAIL treatment, playing an important role in TRAIL-induced Akt phosphorylation. Taken together, c-Cbl may act as a mediator to regulate the Src-PI3K-Akt signal transduction pathway during TRAIL treatment. 相似文献
938.
Jung Woong Choi Seyoung Lim Yong-Seok Oh Eung-Kyun Kim Sun-Hee Kim Yun-Hee Kim Kyun Heo Jaeyoon Kim Jung Kuk Kim Yong Ryul Yang Sung Ho Ryu Pann-Ghill Suh 《Cellular signalling》2010,22(7):1153-1161
Among phospholipase C (PLC) isozymes (β, γ, δ, ε, ζ and η), PLC-β plays a key role in G-protein coupled receptor (GPCR)-mediated signaling. PLC-β subtypes are often overlapped in their distribution, but have unique knock-out phenotypes in organism, suggesting that each subtype may have the different role even within the same type of cells. In this study, we examined the possibility of the differential coupling of each PLC-β subtype to GPCRs, and explored the molecular mechanism underlying the specificity. Firstly, we found that PLC-β1 and PLC-β3 are activated by bradykinin (BK) or lysophosphatidic acid (LPA), respectively. BK-triggered phosphoinositides hydrolysis and subsequent Ca2+ mobilization were abolished specifically by PLC-β1 silencing, whereas LPA-triggered events were by PLC-β3 silencing. Secondly, we showed the evidence that PDZ scaffold proteins is a key mediator for the selective coupling between PLC-β subtype and GPCR. We found PAR-3 mediates physical interaction between PLC-β1 and BK receptor, while NHERF2 does between PLC-β3 and LPA2 receptor. Consistently, the silencing of PAR-3 or NHERF2 blunted PLC signaling induced by BK or LPA respectively. Taken together, these data suggest that each subtype of PLC-β is selectively coupled to GPCR via PDZ scaffold proteins in given cell types and plays differential role in the signaling of various GPCRs. 相似文献
939.
Jae J. Song Miroslaw Jerzy Szczepanski So Young Kim Joo-Hang Kim Jee Young An Yong Tae Kwon Marco A. Alcala David L. Bartlett Yong J. Lee 《Cellular signalling》2010,22(3):553-563
We previously reported two modes of development of acquired TRAIL resistance: early phase and late phase [1]. In these studies, we observed that greater Akt activity and the expression of Bcl-xL were related mainly to the late phase of acquired TRAIL resistance.Recently we became aware of a possible mechanism of early phase TRAIL resistance development through internalization and degradation of TRAIL receptors (DR4 and DR5). Our current studies demonstrate that TRAIL receptors rapidly diminish at the membrane as well as the cytoplasm within 4 h after TRAIL exposure, but recover completely after one or two days. Our studies also reveal that Cbl, a ubiquitously expressed cytoplasmic adaptor protein, is responsible for the rapid degradation of TRAIL receptors; Cbl binds to them and induces monoubiquitination of these receptors concurrent with their degeneration soon after TRAIL exposure, creating the early phase of acquired TRAIL resistance. 相似文献
940.
Effects of microclimate,litter type,and mesh size on leaf litter decomposition along an elevation gradient in the Wuyi Mountains,China 总被引:1,自引:0,他引:1
Litter decomposition is an important ecosystem process regulated by both biotic factors (e.g., decomposers and litter types)
and abiotic factors (e.g., temperature and moisture). This study examined the regulatory effects of soil fauna and microclimate
on decomposition of two substrates (Castanopsis carlesii and Pinus taiwanensis) along an elevation gradient in four ecosystems of zonal vegetation types in southeastern China: evergreen broadleaf forest
(EVB), coniferous forest (COF), dwarf forest (DWF), and alpine meadow (ALM). Our objective was to identify the mechanisms
by which microclimate, substrate, and fauna control litter decomposition, especially where variations in ecosystem structure
and environment are markedly shown across an elevation gradient. The hypotheses were as follows: (1) litter decomposition
within the same litter type would decrease across the elevation gradient, (2) litter decomposition would be lower in poorer
nutrient quality substrate across the four sites, and (3) litter dynamics, influenced by strong interactions among ecosystem
type, litter type, and decomposers, would vary by elevation gradient due to microclimate effects (i.e., temperature and moisture).
The decomposition rates of C. carlesii were significantly higher than those of P. taiwanensis at EVB, COF, and DWF sites; however, they were not significantly different at the ALM site. Low elevation forests possessed
a microclimate (warm and humid) that favors decomposer activities and also appeared to possess a decomposer community adapted
to consuming large amounts of leaf litter, as indicated by the rapid leaf litter loss. Litter decomposition in micro-mesh
bags proceeded more slowly compared to litter in meso-mesh and macro-mesh litterbags across the elevation gradient, indicating
that restricting some detritivore access to litter reduced litter mass loss. We suggest that microclimate and faunal contributions
to plant litter decomposition differ markedly across the ecosystems in the Wuyi Mountains. 相似文献