Effects of Lead on the Morphology and Structure of the Nucleolus in the Root Tip Meristematic Cells of Allium cepa L.

To study the toxic mechanisms of lead (Pb) in plants, the effects of Pb on the morphology and structure of the nucleolus in root tip meristematic cells of Allium cepa var. agrogarum L. were investigated. Fluorescence labeling, silver-stained indirect immunofluorescent microscopy and western blotting were used. Fluorescence labeling showed that Pb ions were localized in the meristematic cells and the uptake and accumulation of Pb increased with treatment time. At low concentrations of Pb (1–10 μM) there were persistent nucleoli in some cells during mitosis, and at high concentration (100 μM) many of the nucleolar organizing regions were localized on sticky chromosomes in metaphase and anaphase cells. Pb induced the release of particles containing argyrophilic proteins to be released from the nucleus into the cytoplasm. These proteins contained nucleophosmin and nucleolin. Pb also caused the extrusion of fibrillarin from the nucleus into the cytoplasm. Western blotting demonstrated the increased expression of these three major nucleolar proteins under Pb stress.     

基于合作博弈与用户联盟的网损分摊方法研究

就网损分摊问题提出一种新的分摊方法来解决参与者之间的网损分摊问题。与传统的网损分摊方法相比,有利于总网损降低,具有较强的经济导向性。     

Transmission Cost Allocation Based on Data Envelopment Analysis and Cooperative Game Method

Transmission cost allocation is a traditional but challenging problem in electric power industries. Many factors can affect the transmission cost allocation. But most traditional allocation methods focus on just one point. The Data Envelopment Analysis (DEA) approach has the characteristic of multi-criterion. It can overcome the drawbacks of traditional allocation methods. This paper combines the game theory and DEA approach to solve the problem of transmission cost allocation. In order to take various key points of power transmission into account, three criterions are proposed. These criterions reflect the effect of load demand, transmission line usage and marginal cost on transmission cost allocation. Nucleolus and Shapley value are used to solve the DEA game programming. For measuring the fairness of the transmission cost allocation methods, this paper proposes an algorithm to evaluate the satisfaction of users with the different allocation methods. The DEA game approach is applied to IEEE 14-bus system. The results which are compared with that of other three traditional allocation methods demonstrate the applicability of the proposed method.     

输电网合作投资费用的计算与分摊

电力市场环境下,输电费用的计算和分摊成为必须解决的问题之一。而此时各发电厂和用户都将成为独立行为的个体,他们具有合作的潜力以降低成本或获得最大利益。利用输电网的合作特性．给出了由发电厂投资修建输电网的计算方法,并提出结合合作博弈理论,采用核心、核仁、夏普利值三种方法将成本分摊到各个用户。     

Nucleolar Proteins and Non-Coding RNAs: Roles in Renal Cancer

Renal cell cancer is the most frequent kidney malignancy. Most RCC cases are classified as clear cell renal cell carcinoma (ccRCC), characterized by high aggressiveness and poor prognosis for patients. ccRCC aggressiveness is defined by classification systems based on changes in morphology of nucleoli, the membraneless substructures of nuclei. The latter act as the sites of ribosome biogenesis as well as the hubs that trap and immobilize proteins, preventing their action in other cellular compartments. Thereby, nucleoli control cellular functioning and homeostasis. Nucleoli are also the sites of activity of multiple noncoding RNAs, including snoRNAs, IGS RNA, and miRNAs. Recent years have brought several remarkable discoveries regarding the role of nucleolar non-coding RNAs, in particular snoRNAs, in ccRCC. The expression of snoRNAs is largely dysregulated in ccRCC tumors. snoRNAs, such as SNHG1, SNHG4 and SNHG12, act as miRNA sponges, leading to aberrant expression of oncogenes and tumor suppressors, and directly contributing to ccRCC development and progression. snoRNAs can also act without affecting miRNA functioning, by altering the expression of key oncogenic proteins such as HIF1A. snoRNAs are also potentially useful biomarkers of ccRCC progression. Here, we comprehensively discuss the role of nucleolar proteins and non-coding RNAs in ccRCC.     

High-Resolution Crystal Structure of Muscle Phosphoglycerate Mutase Provides Insight into Its Nuclear Import and Role

Phosphoglycerate mutase (PGAM) is a glycolytic enzyme converting 3-phosphoglycerate to 2-phosphoglycerate, which in mammalian cells is expressed in two isoforms: brain (PGAM1) and muscle (PGAM2). Recently, it was shown that besides its enzymatic function, PGAM2 can be imported to the cell nucleus where it co-localizes with the nucleoli. It was suggested that it functions there to stabilize the nucleolar structure, maintain mRNA expression, and assist in the assembly of new pre-ribosomal subunits. However, the precise mechanism by which the protein translocates to the nucleus is unknown. In this study, we present the first crystal structure of PGAM2, identify the residues involved in the nuclear localization of the protein and propose that PGAM contains a “quaternary nuclear localization sequence (NLS)”, i.e., one that consists of residues from different protein chains. Additionally, we identify potential interaction partners for PGAM2 in the nucleoli and demonstrate that 14-3-3ζ/δ is indeed an interaction partner of PGAM2 in the nucleus. We also present evidence that the insulin/IGF1–PI3K–Akt–mTOR signaling pathway is responsible for the nuclear localization of PGAM2.