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1.
Voltage-gated calcium channels(VGCCs) play critical roles in cardiac and skeletal muscle contractions,hormone and neurotransmitter release,as well as slower processes such as cell proliferation,differentiation,migration and death.Mutations in VGCCs lead to numerous cardiac,muscle and neurological disease,and their physiological function is tightly regulated by kinases,phosphatases,G-proteins,calmodulin and many other proteins.Fifteen years ago,RGK proteins were discovered as the most potent endogenous regulators of VGCCs.They are a family of monomeric GTPases(Rad,Rem,Rem2,and Gem/Kir),in the superfamily of Ras GTPases,and they have two known functions: regulation of cytoskeletal dynamics including dendritic arborization and inhibition of VGCCs.Here we review the mechanisms and molecular determinants of RGK-mediated VGCC inhibition,the physiological impact of this inhibition,and recent evidence linking the two known RGK functions. 相似文献
2.
MENG Yan ZHOU Xueyan LI Yang ZHAO Dan LIANG Shuyuan ZHAO Xuejian YANG Baoxue . Department of Pathophysiology School of Medical Science Jilin University Changchun China . The Third Hospital of Jilin University Changchun China . Departments of Medicine University of California San Francisco CA - USA 《中国科学:生命科学英文版》2005,48(6):636-640
Jk (kidd) blood group antigens are carried by the urea transporter UT-B[1,2]. The Jknull phenotype, lack-ing urea permeability in erythrocytes[3,4], has a very low frequency in all populations except Polynesians and Finns[5]. In Japan, only 14 individuals with Jk (a-b-) phenotype were identified from 638460 screened donor’s blood samples using the 2 mol/L urea solution hemolysis test[6]. The frequency of Jknull is 0.27% in Polynesian, about 0.03% in Finland[7], and extremely rare in Fran… 相似文献
3.
ZHANG Hao FANG Yan HUANG Cuifen YANG Xiao & YE Qinong Beijing Institute of Biotechnology Beijing China 《中国科学:生命科学英文版》2005,48(3):270-276
Pescadillo was initially identified in a genetic screen for mutations that affect embryonic develop-ment of the zebrafish Daniorerio[1]. Pescadillo-/- ze-brafish mutants showed abnormal embryonic devel-opment such as reduced brain, eye size and a lack of extension of the jaw on developmental day 3. Further study showed that the Pescadillo protein is mainly distributed in tissues containing a significant number of proliferating cells and dramatically elevated in ma-lignant human astrocytomas an… 相似文献
4.
The importance of aquatic vegetation to the ecologi-cal restoration has been recognized commonly bylimnolo-gists and lake managements[1—4].As to the ecologicalrestoration in eutrophicated lakes,it is of great signifi-cance to knowthe dynamic process of the ecosystemevo-lution in a macrophyte-dominated lake under the humanimpacts in historical period,to make it clear whether thecommunitystructure and ecological function would be af-fected bythe extension of the vegetation growth,tofind asolutionto remain ste... 相似文献
5.
MEI-LING YANG HAI-HUA WU YA-PING GUO EN-BO MA 《Insect Science》2006,13(1):41-47
We evaluate comparative toxicity of malathion in the two populations of the grasshopper Oxya chinensis, collected from Daixian and Fanshi of Shanxi province, China. General esterases and acetylcholinesterase (ACHE) from the two populations were characterized and compared. LD50 of the Daixian population (7.58 μg/g body weight) was 2.02-fold higher than that of the Fanshi population (3.75μg/g body weight). General esterase-specific activities in the Daixian population were 1.91,130 and 1.85-fold higher than those in the Fanshi population, when α-NA, α-NB and β-NA were used as a substrate, respectively. Kinetic studies of general esterase showed that Vmax values of general esterases hydrolyzing α-NA,α-NB and β-NA in the Daixian population were 2.15-, 1.12-, and 1.47-fold, respectively, higher than those in the Fanshi population. The AChE activity of the Fanshi population was 1.54-fold higher than that of the Daixian population. Kinetic analysis of AChE showed that significant differences were presented between the two populations in the Km values; and the Vmax value in the Fanshi population was higher than that in the Daixian population. Inhibition studies of AChE indicated that AChE from the Daixian population was 2.56-, 2.80-, and 2.29-fold less sensitive to inhibition by paraoxon, chlorpyrifos-oxon, and demeton-S-methyl, respectively, than that from the Fanshi population. These biochemical characterizations of general esterases and AChE were consistent with malathion bioassay in the two populations. It is inferred that the reduced sensitivity of altered AChE and increased general esterase activities play an important role in the differences of insusceptibility of Oxya chinensis to malathion between the two populations. 相似文献
6.
XIAO-DONG YU TIAN-HONG LUO JIAN YANG HONG-ZHANG ZHOU 《Insect Science》2006,13(2):127-135
Abstract The influence of edge effect on ground-dwelling beetles (Coleoptera) across a forest-clearcut ecotone was studied in Wolong Natural Reserve, southwestern China. During the field research, a total of 30 739 beetles were collected with pitfall traps along transects, which extending 100 m from the edge into the forest interior and 100 m into the clearcut. Of the collection, Carabidae comprised 92%, Staphylinidae 3%, Curculionidae 2%, and Tenebrionidae 2%, and these four families can be considered as abundant groups. Family richness, Shannon diversity and equitability display a significant decrease from forest interior, edge to clearcut. Based on the family composition and abundance, ground-dwelling beetles of the forest interior can be separated from those in the clearcut by Principal coordinate analysis ordination, and beetle assemblages in the forest edge were more similar to forest assemblages than to those found in the clearcut by cluster analysis. Seasonal dynamics of family richness showed a monotone peak in the middle season, with a highest value in the forest interior and a lowest value in the clearcut. Family abundance showed two peaks in the middle season, always with more individuals in the clearcut than in the forest interior or in the edge. Multiple linear regression analyses showed that the cover of shrub and litter were the two most important factors in determining family richness, Shannon diversity, equitability and abundance. Our results show that the forest edge and clearcut have obviously different composition and diversity of ground-dwelling beetles from forest interior at the family level. However, more edges have been formed due to increasing forest fragmentation (clearcutting or logging), so it is necessary to preserve large and intact forest to protect the diversity of ground-dwelling beetles in Wolong Natural Reserve. 相似文献
7.
YANG Lei RONG WeiQi XIAO Ting ZHANG Ying XU Bin LIU Yu WANG LiMing WU Fan QI Jun ZHAO XiuYing WANG HongXia HAN NaiJun GUO SuPing WU JianXiong GAO YanNing CHENG ShuJun 《中国科学:生命科学英文版》2013,56(7):638-646
For successful therapy, hepatocellular carcinoma (HCC) must be detected at an early stage. Herein, we used a proteomic approach to analyze the secretory/releasing proteome of HCC tissues to identify plasma biomarkers. Serum-free conditioned media (CM) were collected from primary cultures of cancerous tissues and surrounding noncancerous tissues. Proteomic analysis of the CM proteins permitted the identification of 1365 proteins. The enriched molecular functions and biological processes of the CM proteins, such as hydrolase activity and catabolic processes, were consistent with the liver being the most important metabolic organ. Moreover, 19% of the proteins were characterized as extracellular or membrane-bound. For validation, secretory proteins involved in transforming growth factor-β signaling pathways were validated in plasma samples. Alphafetoprotein (AFP), metalloproteinase (MMP)1, osteopontin (OPN), and pregnancy-specific beta-1-glycoprotein (PSG)9 were significantly increased in HCC patients. The overall performance of MMP1 and OPN in the diagnosis of HCC remained greater than that of AFP. In addition, this study represents the first report of MMP1 as a biomarker with a higher sensitivity and specificity than AFP. Thus, this study provides a valuable resource of the HCC secretome with the potential to investigate serological biomarkers. MMP1 and OPN could be used as novel biomarkers for the early detection of HCC and to improve the sensitivity of biomarkers compared with AFP. 相似文献
8.
DUAN AiPing NING LiMin LI Chao HOU YaFei YANG NaNa SUN LiZhou LI GenXi 《中国科学:生命科学英文版》2013,56(4):293-297
Hepatitis C virus (HCV), a positive single-stranded RNA virus, is a major cause of liver disease in humans. Herein we report a novel strategy to inhibit the reproduction and translation of HCV using a short RNA, named an Additional RNA, to activate the endonuclease activity of Argonaute 2 (Ago2). In the presence of the Additional RNA, the HCV genome RNA has the requisite 12 nucleotides of base-pairing with microRNA-122. This activates the endonuclease activity of Ago2, resulting in cleavage and release of the HCV genome RNA from Ago2 and microRNA-122. The free HCV genome RNA would be susceptible to intracellular degradation, effectively inhibiting its reproduction and translation. This study presents a new method to inhibit HCV that may hold great potential for HCV treatment in the future. 相似文献
9.
10.
ZHANG Dian YUAN Bingxiang DENG Xiuling YANG Guangde HE Langchong ZHANG Youyi & HAN Qide . School of Medicine Xi''''an Jiaotong University Xi''''an China . College of pharmacy Xi''''an Jiaotong University Xi''''an China . Third Hospital Beijing University Beijing China 《中国科学:生命科学英文版》2004,(4)
Copyright by Science in China Press 2004 The a1-AR is present in many tissues including heart, blood vessels, liver, brain, kidney, prostate and spleen. In these tissues, the a1-AR mediates a variety of physiological effects such as neurotransmission, vasoconstriction, cardiacinotropy, chronotropy and glycogenolysis[1]. In 1986, Morrow and Greese pro-posed that a1-AR should be subclassified into two subtypes. Later this hypothesis was proved by Q.D Han in 1987. He not only verified a1-A… 相似文献