Transcriptional Activation of TINF2, a Gene Encoding the Telomere-Associated Protein TIN2, by Sp1 and NF-κB Factors

The expression of the telomere-associated protein TIN2 has been shown to be essential for early embryonic development in mice and for development of a variety of human malignancies. Recently, germ-line mutations in TINF2, which encodes for the TIN2 protein, have been identified in a number of patients with bone-marrow failure syndromes. Yet, the molecular mechanisms that regulate TINF2 expression are largely unknown. To elucidate the mechanisms involved in human TINF2 regulation, we cloned a 2.7 kb genomic DNA fragment containing the putative promoter region and, through deletion analysis, identified a 406 bp region that functions as a minimal promoter. This promoter proximal region is predicted to contain several putative Sp1 and NF-κB binding sites based on bioinformatic analysis. Direct binding of the Sp1 and NF-κB transcription factors to the TIN2 promoter sequence was demonstrated by electrophoretic mobility shift assay (EMSA) and/or chromatin immunoprecipitation (ChIP) assays. Transfection of a plasmid carrying the Sp1 transcription factor into Sp-deficient SL2 cells strongly activated TIN2 promoter-driven luciferase reporter expression. Similarly, the NF-κB molecules p50 and p65 were found to strongly activate luciferase expression in NF-κB knockout MEFs. Mutating the predicted transcription factor binding sites effectively reduced TIN2 promoter activity. Various known chemical inhibitors of Sp1 and NF-κB could also strongly inhibit TIN2 transcriptional activity. Collectively, our results demonstrate the important roles that Sp1 and NF-κB play in regulating the expression of the human telomere-binding protein TIN2, which can shed important light on its possible role in causing various forms of human diseases and cancers

Metarhodopsin control by arrestin, light-filtering screening pigments, and visual pigment turnover in invertebrate microvillar photoreceptors

The visual pigments of most invertebrate photoreceptors have two thermostable photo-interconvertible states, the ground state rhodopsin and photo-activated metarhodopsin, which triggers the phototransduction cascade until it binds arrestin. The ratio of the two states in photoequilibrium is determined by their absorbance spectra and the effective spectral distribution of illumination. Calculations indicate that metarhodopsin levels in fly photoreceptors are maintained below ~35% in normal diurnal environments, due to the combination of a blue-green rhodopsin, an orange-absorbing metarhodopsin and red transparent screening pigments. Slow metarhodopsin degradation and rhodopsin regeneration processes further subserve visual pigment maintenance. In most insect eyes, where the majority of photoreceptors have green-absorbing rhodopsins and blue-absorbing metarhodopsins, natural illuminants are predicted to create metarhodopsin levels greater than 60% at high intensities. However, fast metarhodopsin decay and rhodopsin regeneration also play an important role in controlling metarhodopsin in green receptors, resulting in a high rhodopsin content at low light intensities and a reduced overall visual pigment content in bright light. A simple model for the visual pigment–arrestin cycle is used to illustrate the dependence of the visual pigment population states on light intensity, arrestin levels and pigment turnover

Recent lepidopteran records from sub-Antarctic South Georgia

No Lepidoptera (butterflies and moths) are known to be residents of South Georgia. This paper presents new records of three lepidopterans on the island. Two, Agrotis ipsilon (Noctuidae) and Plutella xylostella (Yponomeutidae), are well-known migrants. The third, Plodia interpunctella (Pyralidae), is closely associated with human habitation. In the context of regional trends of climate warming P. xylostella may already possess the ecophysiological capacity to permit establishment on South Georgia

Dental nonmetric investigation of population dynamics at Mayapan

Dental morphological traits have demonstrated utility in the analysis of genetic relationships between populations, within a population, and sometimes even at the familial level. However, despite this potential, such studies of the Maya are rare, though recent years have seen this trend reverse. This chapter contributes to this growing body of research on Maya dental morphology by demonstrating the utility of this approach to illuminate aspects of Mayapan’s internal population dynamics

Disaster management

© Springer International Publishing AG 2018. Natural disasters, whether of meteorological origin such as cyclones, floods, tornadoes and droughts or of having geological nature such as earthquakes and volcanoes, are well known for their devastating impacts on human life, economy and environment, and are also formidable physical constraints in our overall efforts to develop and utilize the natural resources on a sustainable basis (Jayaraman, Chandrasekhar, Rao, Acra Astronaut 40(2–8):291–325, 1997, [1])