Singing from the Grave: DNA from a 180 Year Old Type Specimen Confirms the Identity of Chrysoperla carnea (Stephens)

Copyright: © 2015 Price et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. The attached file is the published version of the article

Control of Pre-mRNA Splicing by the General Splicing Factors PUF60 and U2AF65

Pre-mRNA splicing is a crucial step in gene expression, and accurate recognition of splice sites is an essential part of this process. Splice sites with weak matches to the consensus sequences are common, though it is not clear how such sites are efficiently utilized. Using an in vitro splicing-complementation approach, we identified PUF60 as a factor that promotes splicing of an intron with a weak 3' splice-site. PUF60 has homology to U2AF(65), a general splicing factor that facilitates 3' splice-site recognition at the early stages of spliceosome assembly. We demonstrate that PUF60 can functionally substitute for U2AF(65)in vitro, but splicing is strongly stimulated by the presence of both proteins. Reduction of either PUF60 or U2AF(65) in cells alters the splicing pattern of endogenous transcripts, consistent with the idea that regulation of PUF60 and U2AF(65) levels can dictate alternative splicing patterns. Our results indicate that recognition of 3' splice sites involves different U2AF-like molecules, and that modulation of these general splicing factors can have profound effects on splicing

Tracking Ca2+ ATPase intermediates in real time by x-ray solution scattering

Sarco/endoplasmic reticulum Ca2+ ATPase (SERCA) transporters regulate calcium signaling by active calcium ion reuptake to internal stores. Structural transitions associated with transport have been characterized by x-ray crystallography, but critical intermediates involved in the accessibility switch across the membrane are missing. We combined time-resolved x-ray solution scattering (TR-XSS) experiments and molecular dynamics (MD) simulations for real-time tracking of concerted SERCA reaction cycle dynamics in the native membrane. The equilibrium [Ca2] E1 state before laser activation differed in the domain arrangement compared with crystal structures, and following laser-induced release of caged ATP, a 1.5-ms intermediate was formed that showed closure of the cytoplasmic domains typical of E1 states with bound Ca2+ and ATP. A subsequent 13-ms transient state showed a previously unresolved actuator (A) domain arrangement that exposed the ADP-binding site after phosphorylation. Hence, the obtained TR-XSS models determine the relative timing of so-far elusive domain rearrangements in a native environment

MicroRNAs are exported from malignant cells in customized particles

MicroRNAs (miRNAs) are released from cells in association with proteins or microvesicles. We previously reported that malignant transformation changes the assortment of released miRNAs by affecting whether a particular miRNA species is released or retained by the cell. How this selectivity occurs is unclear. Here we report that selectively exported miRNAs, whose release is increased in malignant cells, are packaged in structures that are different from those that carry neutrally released miRNAs (n-miRNAs), whose release is not affected by malignancy. By separating breast cancer cell microvesicles, we find that selectively released miRNAs associate with exosomes and nucleosomes. However, n-miRNAs of breast cancer cells associate with unconventional exosomes, which are larger than conventional exosomes and enriched in CD44, a protein relevant to breast cancer metastasis. Based on their large size, we call these vesicles L-exosomes. Contrary to the distribution of miRNAs among different microvesicles of breast cancer cells, normal cells release all measured miRNAs in a single type of vesicle. Our results suggest that malignant transformation alters the pathways through which specific miRNAs are exported from cells. These changes in the particles and their miRNA cargo could be used to detect the presence of malignant cells in the body

High-risk HPV E5-induced cell fusion: a critical initiating event in the early stage of HPV-associated cervical cancer

<p>Abstract</p> <p>Background</p> <p>Cervical cancer is strongly associated with high-risk human papillomavirus (HPV) and viral oncoproteins E5, E6 and E7 can transform cells by various mechanisms. It is proposed that oncogenic virus-induced cell fusion may contribute to oncogenesis if p53 or apoptosis is perturbed simultaneously. Recently, HPV-16 E5 was found to be necessary and sufficient for the formation of tetraploid cells, which are frequently found in precancerous cervical lesions and its formation is strongly associated with HPV state.</p> <p>Presentation of the hypothesis</p> <p>We propose that high-risk HPV E5-induced cell fusion is a critical initiating event in the early stage of HPV-associated cervical cancer.</p> <p>Testing the hypothesis</p> <p>Our hypothesis can be tested by comparing the likelihood for colony formation or tumorigenic ability in nude mice between normal HaCaT cells expressing all three oncogenic proteins and E5-induced bi-nucleated HaCaT cells expressing E6 and E7. Moreover, investigating premature chromosome condensation (PCC) in HPV-positive and negative precancerous cervical cells is another way to assess this hypothesis.</p> <p>Implication of the hypothesis</p> <p>This viewpoint would change our understanding of the mechanisms by which HPV induces cervical cancer. According to this hypothesis, blocking E5-induced cell fusion is a promising way to prevent the progression of cervical cancer. Additionally, establishment of a role of cell fusion in cervical carcinogenesis is of reference value for understanding the pathogenesis of other virus-associated cancers.</p

Estudio paramétrico simplificado del comportamiento térmico de un satélite en órbita baja terrestre

En el presente trabajo se presenta un modelo simplificado que permite realizar predicciones sobre el comportamiento térmico de un microsatélite. En este modelo se presentan los datos y resultados en forma paramétrica lo cual brinda la ventaja de estudiar distintas configuraciones en el espacio de diseño. Se consigna la notación utilizada, análisis de cargas térmicas -para diversas hipótesis-, ecuaciones y parametrización del problema, rango de valores explorados en el espacio de diseño, simulaciones realizadas, discusión de resultados y conclusiones.Tema: Modelización y Simulación.Asociación Argentina de Energía Sola

Estudio paramétrico simplificado del comportamiento térmico de un satélite en órbita baja terrestre

En el presente trabajo se presenta un modelo simplificado que permite realizar predicciones sobre el comportamiento térmico de un microsatélite. En este modelo se presentan los datos y resultados en forma paramétrica lo cual brinda la ventaja de estudiar distintas configuraciones en el espacio de diseño. Se consigna la notación utilizada, análisis de cargas térmicas - para diversas hipótesis-, ecuaciones y parametrización del problema, rango de valores explorados en el espacio de diseño, simulaciones realizadas, discusión de resultados y conclusiones.Facultad de Arquitectura y Urbanism

The Problem of Colliding Networks and its Relation to Cancer

Complex systems, ranging from living cells to human societies, can be represented as attractor networks, whose basic property is to exist in one of allowed states, or attractors. We noted that merging two systems that are in distinct attractors creates uncertainty, as the hybrid system cannot assume two attractors at once. As a prototype of this problem, we explore cell fusion, whose ability to combine distinct cells into hybrids was proposed to cause cancer. By simulating cell types as attractors, we find that hybrids are prone to assume spurious attractors, which are emergent and sporadic states of networks, and propose that cell fusion can make a cell cancerous by placing it into normally inaccessible spurious states. We define basic features of hybrid networks and suggest that the problem of colliding networks has general significance in processes represented by attractor networks, including biological, social, and political phenomena

Selective Release of MicroRNA Species from Normal and Malignant Mammary Epithelial Cells

MicroRNAs (miRNAs) in body fluids are candidate diagnostics for a variety of conditions and diseases, including breast cancer. One premise for using extracellular miRNAs to diagnose disease is the notion that the abundance of the miRNAs in body fluids reflects their abundance in the abnormal cells causing the disease. As a result, the search for such diagnostics in body fluids has focused on miRNAs that are abundant in the cells of origin. Here we report that released miRNAs do not necessarily reflect the abundance of miRNA in the cell of origin. We find that release of miRNAs from cells into blood, milk and ductal fluids is selective and that the selection of released miRNAs may correlate with malignancy. In particular, the bulk of miR-451 and miR-1246 produced by malignant mammary epithelial cells was released, but the majority of these miRNAs produced by non-malignant mammary epithelial cells was retained. Our findings suggest the existence of a cellular selection mechanism for miRNA release and indicate that the extracellular and cellular miRNA profiles differ. This selective release of miRNAs is an important consideration for the identification of circulating miRNAs as biomarkers of disease

The Social Relations Approach, empowerment and women factory workers in Malaysia

This article discusses the empowerment of women factory workers in Malaysia through the lens of Kabeer’s Social Relations Approach. The approach offers an institutional analysis of how gender inequality is produced and calls for the overall terms of exchange and cooperation to be shifted in women’s favour. Its application shows that Malaysian women factory workers face significant challenges, due to the character of institutions, and women’s difficulties in adopting and internalising the notion of ‘empowerment’