Histone methylation plays an important role in eukaryotic transcriptional regulation. A number of histone methyltransferases (HMTases) with distinct functions have been identified. The HSPC069/HYPB gene was originally isolated from the human hematopoietic stem/progenitor cells (HSPCs), and it was also identified as a huntingtin interacting protein, implicated in the pathogenesis of Huntington disease (HD). However, its biochemical function is poorly understood. Here we report the structural and functional characterization of the huntingtin interacting protein B (HYPB). 1) The triplicate AWS-SET-PostSET domains mediate a histone H3 lysine 36 specific HMTase activity. 2) A low charged region that is rich in glutamine and proline has been characterized as a novel transcriptional activation domain. The structural features of this region are evolutionarily conserved in vertebrates. 3) Coimmunoprecipitation assays indicate that HYPB protein associates with hyperphosphorylated RNA polymerase II (RNAPII) but not the unphosphorylated form. Furthermore, the RNAPII-association region of HYPB protein has been identified to encompass the C-terminal 142 amino acids. Thus, our results suggest that HYPB HMTase may coordinate histone methylation and transcriptional regulation in mammals and open perspective for the further study of the potential roles of HYPB protein in hematopoiesis and pathogenesis of HD.Nucleosome, the bead-like unit of DNA packaging in eukaryotic cells, consists of DNA wound around a protein core made up of eight histone molecules. Covalent modifications of the N-terminal tails of the core histones have emerged as key regulatory mechanisms of gene expression (1-3). These histone modifications, including acetylation, phosphorylation, ubiquitination, and methylation, create both synergistic and antagonistic signals that correlate with the transcriptional activity of a gene, through recruiting/dispelling some protein complexes or through changing the structure of chromatin to allow access for RNA polymerase to initiate transcription. Moreover, these histone modifications and the consequent changes in chromatin structure may serve as an epigenetic marking system that is responsible for establishing and maintaining the heritable programs of gene expression during cellular differentiation and organism development (4, 5).Methylations of histone lysine residues, with exception of H3 lysine 79, are catalyzed by a family of SET domain-containing proteins (6). The SET domain is an evolutionarily conserved, ϳ130-amino acid sequence motif. It was originally identified in members of polycomb group (PcG), trithorax group (trxG), and Su(var) genes and was named after the genes Su(var)3-9, Enhancer of zeste (E(z)) and trithorax (trx) (7). Not all SET domain-containing proteins possess histone methyltransferase (HMTase) 5 activities. The cysteine-rich regions adjacent to the SET domains are also required (8,9). In addition to the SET domains, most HMTases carry other functional domains such as transcriptional activation or re...

We investigate a unique wireless sensor network scheduling problem in which all nodes in a cluster send exactly one packet to a designated sink node in an effort to minimize transmission time. However, node transmissions must be sufficiently isolated either in time or in space to avoid collisions. The problem is formulated and solved via graph representation. We prove that an optimal transmission schedule can be obtained efficiently through a pipeline-like schedule when the underlying topology is either line or tree. The minimum time required for a line or tree topology with n nodes is 3ðn À 2Þ. We further prove that our scheduling problem is NP-hard for general graphs. We propose a heuristic algorithm for general graphs. Our heuristic tries to schedule as many independent segments as possible to increase the degree of parallel transmissions. This algorithm is compared to an RTS/CTS based distributed algorithm. Preliminary simulated results indicate that our heuristic algorithm outperforms the RTS/CTS based distributed algorithm (up to 30%) and exhibits stable behavior.

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The aim of this paper is to identify the research status quo on pervasive and ubiquitous computing via scientometric analysis. Information visualization and knowledge domain visualization techniques were adopted to determine how the study of pervasive and ubiquitous computing has evolved. A total of 5,914 papers published between 1995 and 2009 were retrieved from the Web of Science with a topic search of pervasive or ubiquitous computing. CiteSpace is a java application for analyzing and visualizing a wide range of networks from bibliographic data. By use of it, we generated the subject category network to identify the leading research fields, the research power network to find out the most productive countries and institutes, the journal co-citation map to identify the distribution of core journals, the author co-citation map to identify key scholars and their co-citation patterns, the document co-citation network to reveal the ground-breaking literature and detect the co-citation clusters on pervasive and ubiquitous computing, and depicted the hybrid network of keywords and noun phrases to explore research foci on pervasive and ubiquitous computing over the entire span 1995-2009.

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To study the pollution characteristics of PM 2.5 during the haze period in October 2014, the hourly automatic monitoring data and 22-h atmospheric PM 2.5 samples were collected in Changchun city. According to the statistical results of the hourly average PM 2.5 concentration, heavy pollution occurred from October 13 to November 1 in 2014 in Changchun city. The daily concentration of PM 2.5 during this period was 53.18 µg m -3 to 450.69 µg m -3 . In addition, the PM 2.5 concentration was higher at night and lower during the daytime on haze days, which is affected by pollutant emission and meteorological conditions. The Pearson correlation coefficient between PM 2.5 and CO was high (r = 0.745), which implies that the concentration suddenly increased, probably because of the combustion of fossil fuels and other organic matter. The meteorological condition investigation shows that the wind speed, temperature and pressure are low and that the RH value is relatively high on haze days. In addition, stable weather during haze days makes the pollution heavier. The analysis of water-soluble inorganic ions (WSIIs) suggests that WSIIs constituted up to 21-56% of PM 2.5 , and the total ions, anions and cations showed a significant correlation. During the haze days, the NO 3 -/SO 4 2-ratio was substantial (3.7-4.6), except at the CP and JZP stations, which suggests that the pollutants in the atmosphere are from a mixture of stationary emission and mobile emission. The NOR and SOR values were more than 0.1 at most sampling stations, so serious secondary pollution occurs in the atmosphere on haze days, and secondary ion formation is enhanced by the atmospheric conditions and emissions of gaseous SO 2 and NO 2 .

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