Long non-coding RNA HOTAIR in carcinogenesis and metastasis

Long non-coding RNAs （lncRNAs） have gained massive attention in recent years as a potentially new and crucial layer of gene regulation. LncRNAs are prevalently transcribed in the genome, but their roles in gene regulation and disease development are largely unknown. HOX antisense intergenic RNA （HOTAIR）, a lncRNA located in the HOXC locus, has been shown to repress HOXD gene expression and promote breast cancer metastasis. Mechanistically, HOTAIR interacts with and recruits polycomb repressive complex 2 （PRC2） and regulates chromosome occupancy by EZH2 （a subunit of PRC2）, which leads to histone H3 lysine 27 trimethylation of the HOXD locus. Moreover, HOTAIR is pervasively overexpressed in most human cancers compared with noncancerous adjacent tissues. This review summarizes the studies on the HOTAIR lncRNA over the past 6 years.     

Animal personalities and their implications for complex signaling

Animal personalities have been a major focus of behavioral ecology over the past decade. Consistent individual dif ferences in behavior have been found across taxa, and have been shown to influence a range of ecological processes. The role of personalities in sexual selection has been considered, and examples exist that show selection for personality traits with both assortative and disassortative mating patterns between personality types. One overlooked aspect of the personality and sexual se lection literature is the potential for personalitysignaling interactions, specifically with complex signaling. Complex signaling is a diverse topic in itself, and in short, consists of multiple signals within one or more modalities that interact to elicit a receiver response. Research into complex signaling has been thorough, although at times studies discover complex signaling systems that fail to fit into one of the existing hypotheses in the literature. Here, we argue that personalities may interact with complex signal ing, which should be considered by researchers of both personality and sexual selection and communication. We describe several ways in which personalitycomplex signaling interactions could affect both the signaler and receiver, and the way in which they may drive personalityspecific signals as well as receiver preferences. Finally, we discuss how considering personality in com plex signaling studies may inform theory as well as improve the ability of researchers to accurately describe its function.     

Histone modifications dictate specific biological readouts

The basic unit of chromatin is the nucleosomal core particle, containing 147 bp of DNA that wraps twice around an octamer of core histones. The core histones bear a highly dynamic N-terminal amino acid tail around 20-35 residues in length and rich in basic amino acids. These tails extending from the surface of nucleosome play an important role in folding of nucleosomal arrays into higher order chromatin structure, which plays an important role in eukaryotic gene regulation. The amino terminal tails protruding from the nuclesomes get modified by the addition of small groups such as methyl, acetyl and phosphoryl groups. In this review, we focus on these complex modi- fication patterns and their biological functions. Moreover, these modifications seem to be part of a complex scheme where distinct histone modifications act in a sequential manner or in combination to form a ＂histone code＂ read by other proteins to control the structure and/or function of the chromatin fiber. Errors in this histone code may be involved in many human diseases especially cancer, the nature of which could be therapeutically exploited. Increasing evidence suggests that many proteins bear multiple, distinct modifications, and the ability of one modification to antagonize or synergize the deposition of another can have significant biological consequences.     

Open and Closed： The Roles of Linker Histones in Plants and Animals

Histones package DNA in all eukaryotes and play key roles in regulating gene expression. Approximately 150 base pairs of DNA wraps around an octamer of core histones to form the nucleosome, the basic unit of chromatin. Linker histones compact chromatin further by binding to and neutralizing the charge of the DNA between nucleosomes. It is well established that chromatin packing is regulated by a complex pattern of posttranslational modifications （PTMs） to core histones, but linker histone function is less well understood. In this review, we describe the current understand- ing of the many roles that linker histones play in cellular processes, including gene regulation, cell division, and devel- opment, while putting the linker histone in the context of other nuclear proteins. Although intriguing roles for plant linker histones are beginning to emerge, much of our current understanding comes from work in animal systems. Many unanswered questions remain and additional work is required to fully elucidate the complex processes mediated by linker histones in plants.     

Possible role of histone H1 in the regulation of furin-dependent proprotein processing

Histone H1 and its C-terminal lysine rich fragments were recently found to be potent inhibitorsof furin,a mammalian proprotein convertase.However,its role in the regulation of furin-dependent proproteinprocessing remains unclear.Here we report that histone H1 efficiently blocks furin-dependent pro-yonWillebrand factor(pro-vWF)processing in a dose-dependent manner.Coimmunoprecipitation and immunof-luorescence studies confirmed that histone H1 could interact with furin,and the interaction mainly took placeon the cell surface.We noted that histone H1 was released from cells undergoing necrosis and apoptosisinduced by H_2O_2.Our findings suggested that histone H1 might be involved in extracellular and/or intracellu-lar furin regulation.     

Role of plasma membrane lipid composition on cellular homeostasis： learning from cell line models expressing fatty acid desaturases

Experimental evidence has suggested that plasma membrane （PM）-associated signaling and hence cell metabolism and viability depend on lipid composition and organization. The aim of the present work is to develop a cell model to study the endogenous polyunsaturated fatty acids （PUFAs） effect on PM properties and analyze its influence on cholesterol （Chol） homeostasis. We have previously shown that by using a cell line overexpressing stearoyl-CoA-desaturase, membrane composition and organization coordinate cellular pathways involved in Chol efflux and ceil viability by different mechanisms. Now, we expanded our studies to a cell model overexpressing both A5 and A6 desaturases, which resulted in a permanently higher PUFA content in PM. Furthermore, this cell line showed increased PM fluidity, Chol storage, and mitochondrial activity. In addition, human apolipoprotein AI-mediated Chol removal was less efficient in these cells than in the corresponding control. Taken together, our results suggested that the ceil functionality is preserved by regulating PM organization and Chol exportation and homeostasis.