The Transcription Factor YY1 Is a Substrate for Polo-Like Kinase 1 at the G2/M Transition of the Cell Cycle

Yin-Yang 1 (YY1) is an essential multifunctional zinc-finger protein. It has been shown over the past two decades to be a critical regulator of a vast array of biological processes, including development, cell proliferation and differentiation, DNA repair, and apoptosis. YY1 exerts its functions primarily as a transcription factor that can activate or repress gene expression, dependent on its spatial and temporal context. YY1 regulates a large number of genes involved in cell cycle transitions, many of which are oncogenes and tumor-suppressor genes. YY1 itself has been classified as an oncogene and was found to be upregulated in many cancer types. Unfortunately, our knowledge of what regulates YY1 is very minimal. Although YY1 has been shown to be a phosphoprotein, no kinase has ever been identified for the phosphorylation of YY1. Polo-like kinase 1 (Plk1) has emerged in the past few years as a major cell cycle regulator, particularly for cell division. Plk1 has been shown to play important roles in the G/M transition into mitosis and for the proper execution of cytokinesis, processes that YY1 has been shown to regulate also. Here, we present evidence that Plk1 directly phosphorylates YY1 in vitro and in vivo at threonine 39 in the activation domain. We show that this phosphorylation is cell cycle regulated and peaks at G2/M. This is the first report identifying a kinase for which YY1 is a substrate

At the Feet of the Fortress: Analysis of Inka Period (ca. AD 1430-1536) Archaeofaunal Assemblages from Residential Unit 1 (RU1), Pucara de Tilcara (Jujuy, Argentina).

This paper reports the results of a zooarchaeological analysis conducted on the occupation layer of a compound structure (Residential Unit 1) of the Pucara de Tilcara archaeological site (Jujuy Province, northwestern Argentina). Its occupation span extends between the 13th and 15th centuries AD, but evidence diagnostic of the Inka Period (AD 1430-1536) is predominant. Residential Unit 1 was a house-workshop that hosted specialized crafts like metallurgy and lapidary during the Inka Period. It was proposed in previous works that artisans living at Pucara de Tilcara were provisioned with agropastoral products by the Inka administration. This paper aims to test that hypothesis against the zooarchaeological evidence of Residential Unit 1. Three variables were used as proxies for state-sponsored distribution: taxonomic diversity (family and species ranks), and skeletal and age profiles of the predominant zoological family (Camelidae) in the assemblage. The results show a high degree of continuity with the regional record, characterized by a herding-hunting strategy focused on domestic and wild species of Camelidae and a mixed mortality pattern. The skeletal profile shows a strong and negative correlation with the desiccation potential of elements, which could be indicative of local production of chalona. Overall, faunal evidence does not show any sign of centralized distribution

c-Myc Is Essential to Prevent Endothelial Pro-Inflammatory Senescent Phenotype

The proto-oncogene c-Myc is vital for vascular development and promotes tumor angiogenesis, but the mechanisms by which it controls blood vessel growth remain unclear. In the present work we investigated the effects of c-Myc knockdown in endothelial cell functions essential for angiogenesis to define its role in the vasculature. We provide the first evidence that reduction in c-Myc expression in endothelial cells leads to a pro-inflammatory senescent phenotype, features typically observed during vascular aging and pathologies associated with endothelial dysfunction. c-Myc knockdown in human umbilical vein endothelial cells using lentivirus expressing specific anti-c-Myc shRNA reduced proliferation and tube formation. These functional defects were associated with morphological changes, increase in senescence-associated-β-galactosidase activity, upregulation of cell cycle inhibitors and accumulation of c-Myc-deficient cells in G1-phase, indicating that c-Myc knockdown in endothelial cells induces senescence. Gene expression analysis of c-Myc-deficient endothelial cells showed that senescent phenotype was accompanied by significant upregulation of growth factors, adhesion molecules, extracellular-matrix components and remodeling proteins, and a cluster of pro-inflammatory mediators, which include Angptl4, Cxcl12, Mdk, Tgfb2 and Tnfsf15. At the peak of expression of these cytokines, transcription factors known to be involved in growth control (E2f1, Id1 and Myb) were downregulated, while those involved in inflammatory responses (RelB, Stat1, Stat2 and Stat4) were upregulated. Our results demonstrate a novel role for c-Myc in the prevention of vascular pro-inflammatory phenotype, supporting an important physiological function as a central regulator of inflammation and endothelial dysfunction

Holocene landscape changes and wood use in Patagonia: Plant macroremains from Cerro Casa de Piedra 7

This paper studies the different practices employed in the acquisition of woody material used by hunter–gatherer societies from the northwestern region of the Santa Cruz Province, Argentine Patagonia, during the early and middle Holocene. In addressing this theme, we study carbonized and non-carbonized wood recovered from six stratigraphic levels from the Cerro Casa de Piedra 7 site. This research revealed that during the lowest level of occupation, a distinct range of woody species were utilized; these were subsequently absent in the rest of the stratigraphical levels studied. In fact, all the other levels analyzed presented the homogeneous presence of a single plant species: Nothofagus pumilio. This species has the largest representation among both the charcoal and uncharred wood fragments of the six levels studied. The study of the assemblage samples allowed us to identify differences between the various archaeological levels, which could be the product of behavioral and/or environmental differences.Fil: Caruso Fermé, Laura. Universitat Autònoma de Barcelona; EspañaFil: Civalero, Maria Teresa. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Methods of acquisition and use of firewood among hunter-gatherer groups in Patagonia (Argentina) during the Holocene

The present article examines the ways of obtaining firewood and of using it by Patagonian hunter-gatherer groups and the relationship with their high mobility. With these goals, we have selected a range of archaeological sites in varied types of vegetation: forest, forest-steppe ecotone and steppe (according to pollen reconstructions and current records) in several different latitudes of Argentinean Patagonia: Paredón Lanfré (Río Negro province); Cerro Pintado (Chubut province); Cerro Casa de Piedra 7 and Orejas de Burro 1 (Santa Cruz province). The taxa, including Nothofagus pumilio, Austrocedrus chilensis, Ribes magellanicum, Embothrium coccineum and Fabiana imbricata, found among the scattered charcoal remains in the sediments of the four Patagonian sites, show how firewood was gathered in types of vegetation similar to the ones that nowadays surround the archaeological sites. The archaeobotanical results allow us to detect differences and similarities of the supply of wood and its relationship with human mobility, site functionality and the types of occupation.Fil: Caruso, Laura Lihue. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin