Gemini,a Bifunctional Enzymatic and Fluorescent Reporter of Gene Expression

Background

The development of collections of quantitatively characterized standard biological parts should facilitate the engineering of increasingly complex and novel biological systems. The existing enzymatic and fluorescent reporters that are used to characterize biological part functions exhibit strengths and limitations. Combining both enzymatic and fluorescence activities within a single reporter protein would provide a useful tool for biological part characterization.

Methodology/Principal Findings

Here, we describe the construction and quantitative characterization of Gemini, a fusion between the β-galactosidase (β-gal) α-fragment and the N-terminus of full-length green fluorescent protein (GFP). We show that Gemini exhibits functional β-gal activity, which we assay with plates and fluorometry, and functional GFP activity, which we assay with fluorometry and microscopy. We show that the protein fusion increases the sensitivity of β-gal activity and decreases the sensitivity of GFP.

Conclusions/Significance

Gemini is therefore a bifunctional reporter with a wider dynamic range than the β-gal α-fragment or GFP alone. Gemini enables the characterization of gene expression, screening assays via enzymatic activity, and quantitative single-cell microscopy or FACS via fluorescence activity. The analytical flexibility afforded by Gemini will likely increase the efficiency of research, particularly for screening and characterization of libraries of standard biological parts.     

缺氧内皮细胞条件培养液对肺动脉平滑肌细胞b-FGF表达的影响

应用细胞培养、免疫细胞化学和图像分析方法,探讨了缺氧猪肺动脉内皮细胞条件培养液对肺动脉平滑肌细胞碱性成纤维细胞生长因子（ｂＦＧＦ）表达的影响。本研究表明,肺动脉内皮细胞培养汇合前和汇合后均可表达ｂＦＧＦ,在缺氧时其表达增多。缺氧猪肺动脉内皮细胞条件培养液可刺激猪肺动脉平滑肌细胞表达ｂＦＧＦ,将条件培养液加热１００℃处理或加入ｂＦＧＦ抗体后,可使猪肺动脉平滑肌细胞表达ｂＦＧＦ明显减少。这提示缺氧可刺激猪肺动脉内皮细胞表达ｂＦＧＦ,缺氧猪肺动脉内皮细胞条件培养液通过ｂＦＧＦ使肺动脉平滑肌细胞表达ｂＦＧＦ,因此推测缺氧条件下肺动脉内皮细胞ｂＦＧＦ的旁分泌作用可能在肺动脉平滑肌细胞增生中起重要作用,这一过程在缺氧性肺动脉高压时肺动脉结构重建的发生机制中具有重要意义。     

Silencing of ZFP36L2 increases sensitivity to temozolomide through G2/M cell cycle arrest and BAX mediated apoptosis in GBM cells

Molecular Biology Reports - Despite the advancements in primary brain tumour diagnoses and treatments, the mortality rate remains high, particularly in glioblastoma (GBM). Chemoresistance,...     

Enzymatic deinking of various types of waste paper: Efficiency and characteristics

The aim of the present study was to characterize the enzymatic deinking of various types of waste paper. Studies on the optimization of enzymatic deinking have been performed previously using commercially available enzyme preparations containing cellulase and hemicellulase. The enzymatic deinking of different types of waste paper demonstrated a high efficiency of 86.6% on laser-printed paper, but a low deinking efficiency of 12.9% was obtained with newspaper. All enzymatic treatments significantly improved the drainage rate of the deinked waste paper. Enzymatic deinking increased the tensile index of magazine paper but reduced the tensile index of bubble jet-printed paper, photocopy paper and newspaper. Enzymatic hydrolysis caused a 21.1% reduction in the tear index for bubble jet-printed paper, but a 3.1% increase in the tear index was obtained for laser-printed paper relative to respective blank. In addition, enzymatic hydrolysis increased the burst index by 4.7% relative to blank for laser-printed paper. However, photocopy paper showed the highest reduction (8.3%) in the burst index relative to blank. Taken together, these results suggest that enzymatic hydrolysis is both advantageous and detrimental to the mechanical properties of deinked paper. Thus, the proper regulation of enzymatic hydrolysis is crucial to improve the quality of recycled paper.     

The Functional Proximal Proteome of Oncogenic Ras Includes mTORC2

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Universal stress protein in Malus sieversii confers enhanced drought tolerance

Journal of Plant Research - Drought is an important environmental factor that can severely affect plant growth and reproduction. Although many genes related to drought tolerance have been studied...