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A Ras-Dependent Pathway Regulates RNA Polymerase II Phosphorylation in Cardiac Myocytes: Implications for Cardiac Hypertrophy 总被引:2,自引:1,他引:1 下载免费PDF全文
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Meng-yi Lin Kuo-hsing Chai Swee-suak Ko Lin-yun Kuang Huu-Sheng Lur Yee-yung Charng 《Plant physiology》2014,164(4):2045-2053
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The duplication and divergence of heat stress (HS) response genes might help plants adapt to varied HS conditions, but little is known on the topic. Here, we examined the evolution and function of Arabidopsis (Arabidopsis thaliana) mitochondrial GrpE (Mge) proteins. GrpE acts as a nucleotide-exchange factor in the Hsp70/DnaK chaperone machinery. Genomic data show that AtMge1 and AtMge2 arose from a recent whole-genome duplication event. Phylogenetic analysis indicated that duplication and preservation of Mges occurred independently in many plant species, which suggests a common tendency in the evolution of the genes. Intron retention contributed to the divergence of the protein structure of Mge paralogs in higher plants. In both Arabidopsis and tomato (Solanum lycopersicum), Mge1 is induced by ultraviolet B light and Mge2 is induced by heat, which suggests regulatory divergence of the genes. Consistently, AtMge2 but not AtMge1 is under the control of HsfA1, the master regulator of the HS response. Heterologous expression of AtMge2 but not AtMge1 in the temperature-sensitive Escherichia coli grpE mutant restored its growth at 43°C. Arabidopsis T-DNA knockout lines under different HS regimes revealed that Mge2 is specifically required for tolerating prolonged exposure to moderately high temperature, as compared with the need of the heat shock protein 101 and the HS-associated 32-kD protein for short-term extreme heat. Therefore, with duplication and subfunctionalization, one copy of the Arabidopsis Mge genes became specialized in a distinct type of HS. We provide direct evidence supporting the connection between gene duplication and adaptation to environmental stress. 相似文献
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Kuan-Te Li Ya-Lin Lin Ji-Ying Huang Wen-Ya Li Yuh-Chyang Charng 《Molecular breeding : new strategies in plant improvement》2008,22(1):85-94
The maize transposon Ac can move to a new location within the genome to create knockout mutants in transgenic plants. In rice, Ac transposon is very active but sometimes undergoes further transposition and leaves an empty mutated gene. Therefore, we developed
a one-time transposon system by locating one end of the transposon in the intron of the Ac transposase gene, which is under the control of the inducible promoter (PR-1a). Treatment with salicylic acid induced transposition
of this transposon, COYA, leading to transposase gene breakage in exons. The progeny plants inheriting the transposition events become stable knockout
mutants, because no functional transposase could be yielded. The behavior of COYA was analyzed in single-copy transgenic rice plants. We determined the expression of the modified transposase gene and its
ability to trigger transposition events in transgenic rice plants. The COYA element thus exhibits potential for development of an inducible transposon system suitable for gene isolation in heterologous
plant species.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
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Familial hypercholesterolemia (FH) is an autosomal dominant disease caused by mutations in low-density lipoprotein receptor (LDLR), apolipoprotein B-100 (APOB), and proprotein convertase subtilisin/kexin type 9 (PCSK9) genes. This study investigated FH patients carrying common mutations in Taiwan and compared them to FH southeastern Asians. Causal FH mutations were identified by exon-by-exon sequencing with/without multiplex ligation-dependent probe amplification among 208 Taiwanese with clinically diagnosed FH. Haplotype analyses among probands and family members were undertaken using TaqMan® Assays. Totally, LDLR mutations were found in 118 probands, consisting of 61 different loci, and APOB 10579C>T mutations in 12 probands. Three mutations (64delG, 1661C>T, and 2099A>G) were novel. LDLR 986G>A (13.1%), 1747C>T (10.8%), and APOB 10579C>T (9.2%) were common mutations with no differences in phenotypes. LDLR 1747C>T associated with one haplotype (CAAGCCCCATGG/(dTA)n-112nt); LDLR 986G>A with two. APOB 10579C>T associated with the same LDLR binding-domain pattern in Taiwanese and southeastern Asians. We concluded that LDLR 986G>A, 1747C>T and APOB 10579C>T are common mutations, with combined frequency of approximately 33%. The presence of different haplotypes associated with FH common mutations in Taiwan indicates multiple historical migrations, probable multiple recurrent origins from southern China, and haplotype homologies reflect the presence of common ancestors in southern China. 相似文献
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Wu-Lin Charng Shinya Yamamoto Manish Jaiswal Vafa Bayat Bo Xiong Ke Zhang Hector Sandoval Gabriela David Stephen Gibbs Hsiang-Chih Lu Kuchuan Chen Nikos Giagtzoglou Hugo J. Bellen 《PLoS biology》2014,12(1)
Vesicular trafficking plays a key role in tuning the activity of Notch signaling. Here, we describe a novel and conserved Rab geranylgeranyltransferase (RabGGT)-α–like subunit that is required for Notch signaling-mediated lateral inhibition and cell fate determination of external sensory organs. This protein is encoded by tempura, and its loss affects the secretion of Scabrous and Delta, two proteins required for proper Notch signaling. We show that Tempura forms a heretofore uncharacterized RabGGT complex that geranylgeranylates Rab1 and Rab11. This geranylgeranylation is required for their proper subcellular localization. A partial dysfunction of Rab1 affects Scabrous and Delta in the secretory pathway. In addition, a partial loss Rab11 affects trafficking of Delta. In summary, Tempura functions as a new geranylgeranyltransferase that regulates the subcellular localization of Rab1 and Rab11, which in turn regulate trafficking of Scabrous and Delta, thereby affecting Notch signaling. 相似文献
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Yao‐Pin Lin Tsung‐yuan Lee Ayumi Tanaka Yee‐yung Charng 《The Plant journal : for cell and molecular biology》2014,80(1):14-26
Chlorophylls, the most abundant pigments in the photosynthetic apparatus, are constantly turned over as a result of the degradation and replacement of the damage‐prone reaction center D1 protein of photosystem II. Results from isotope labeling experiments suggest that chlorophylls are recycled by reutilization of chlorophyllide and phytol, but the underlying mechanism is unclear. In this study, by characterization of a heat‐sensitive Arabidopsis mutant we provide evidence of a salvage pathway for chlorophyllide a. A missense mutation in CHLOROPHYLL SYNTHASE (CHLG) was identified and confirmed to be responsible for a light‐dependent, heat‐induced cotyledon bleaching phenotype. Following heat treatment, mutant (chlg‐1) but not wild‐type seedlings accumulated a substantial level of chlorophyllide a, which resulted in a surge of phototoxic singlet oxygen. Immunoblot analysis suggested that the mutation destabilized the chlorophyll synthase proteins and caused a conditional blockage of esterification of chlorophyllide a after heat stress. Accumulation of chlorophyllide a after heat treatment occurred during recovery in the dark in the light‐grown but not the etiolated seedlings, suggesting that the accumulated chlorophyllides were not derived from de novo biosynthesis but from de‐esterification of the existing chlorophylls. Further analysis of the triple mutant harboring the CHLG mutant allele and null mutations of CHLOROPHYLLASE1 (CLH1) and CLH2 indicated that the known chlorophyllases are not responsible for the accumulation of chlorophyllide a in chlg‐1. Taken together, our results show that chlorophyll synthase acts in a salvage pathway for chlorophyll biosynthesis by re‐esterifying the chlorophyllide a produced during chlorophyll turnover. 相似文献
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Chen Long-Fang O. Hwang Jia-Yuan Charng Yee-Yung Sun Chi-Wen Yang Shang-Fa 《Molecular breeding : new strategies in plant improvement》2001,7(3):243-257
Transgenic plantlets with a retarding effect on post-harvest yellowing in broccoli have been generated via Agrobacterium tumefaciens-mediated transformation of cytokinin synthesizing ipt (isopentenyltransferase) gene. The ipt gene is constructed under the control of senescence-associated gene promoters from Arabidopsis in the forms of pSG529(+) and pSG766A, which were the gifts from Dr R.M. Amasino at University of Wisconsin, Madison. Evidence of transgene integration was confirmed by assays on neomycin phosphotransferase II (NPTII) activity of selection markers, PCR and Southern hybridization. Based on the chlorophyll retention rate (>50%) after 4 days of post-harvest storage at 25 °C, it was found that 31% of transformants exhibited the effect of retarding yellowing in detached leaves, with 16% having the effect on florets and 7.2% on both leaves and florets. RT-PCR revealed that ipt gene expression occurred early on the day of detachment. Factors such as vacuum aid infiltration, plasmid differences, explant types, seedling ages and kanamycin concentrations were also studied. Putative transformation frequencies tended to vary with plasmids and explant types. The advantage of vacuum aid infiltration depended on explant types. The optimal kanamycin concentration should be determined experimentally for each study to avoid the high escape rate of kanamycin selection. Flow cytometric analysis of explant nuclear DNA phases was found to be helpful for selecting suitable explants for transformation and minimizing the polyploid transformants. A reproducible transformation protocol without any pre-culture was established for explants of hypocotyl, cotyledon, and peduncle. Most of the ipt transformants with a retarding effect on yellowing had a chimeric nature but showed little or no serious morphological abnormality in comparison with their parental line. Through proper selection, transformation lines with the capability of retarding post-harvest yellowing in broccoli should be feasible. 相似文献