Evidence for a posttranscriptional effect of retinoic acid on connexin43 gene expression via the 3′-untranslated region

AbstractAll-trans retinoic acid (10−7 M) induces cell–cell communication and the expression of the gap junction protein connexin43 in mouse F9 teratocarcinoma cells. Previous experiments revealed an increase of mRNA but no change in the transcription of connexin43, suggesting a posttranscriptional mechanism responsible for the regulation of connexin43 gene expression. In transient transfection experiments using an expression vector containing the 3′-untranslated region of the connexin43 gene downstream of the luciferase coding sequence driven by the connexin43 promoter we show here that retinoic acid enhances luciferase activity via the connexin43 3′-untranslated region due to altered stability of the mRNA. Thus, retinoic acid is able to influence connexin43 gene expression at the level of mRNA stability via elements located in the 3′-untranslated region

The isozyme pattern of glutathione S-transferases in rat heart

AbstractThe isozyme pattern of glutathione S-transferases of rat heart differs markedly from that of liver. Heart lacks the majority of basic isozymes recognized in rat liver, and isoelectric focusing of glutathione S-transferases obtained from affinity chromatography on S-hexylglutathione-linked Sepharose 6B revealed that 3 major acidic isozymes with pI values of 6.8, 6.3 and 4.9 are present in heart, at least two of which were not found in liver. In addition, multiple bands were found in the pI range 5.0–5.5 for glutathione S-transferase activity and protein staining

Singlet oxygen inactivates protein tyrosine phosphatase-1B by oxidation of the active site cysteine

Singlet oxygen (1O2), an electronically excited form of molecular oxygen, is a mediator of biological effects of ultraviolet A radiation, stimulating signaling cascades in human cells. We demonstrate here that 1O2 generated by photosensitization or by thermodecomposition of 3,3′-(1,4-naphthylidene)dipropionate-1,4-endoperoxide inactivates isolated protein tyrosine phosphatases (PTPases). PTPase activities of PTP1B or CD45 were abolished by low concentrations of 1O2, but were largely restored by post-treatment with dithiothreitol. Electrospray ionization mass spectrometry analysis of tryptic digests of PTP1B exposed to 1O2 revealed oxidation of active-site Cys215 as the only cysteine residue oxidized. In summary, 1O2 may activate signaling cascades by interfering with phosphotyrosine dephosphorylation.This study was supported by Deutsche Forschungsgemeinschaft (Bonn, Germany; Sonderforschungsbereich 503, Project B1). H.S. is a Fellow of the National Foundation for Cancer Research, Bethesda, MD, USA

New socio-political environments and the dynamics of European public research systems

The performance of science and technology is being challenged by new socio-political environments. The changes in science policy are influenced by a more systemic view of the understanding on how science and technology evolve. The concept of risk society is mediating the links between science and society. Comparative analyses cast doubts about the possibilities of European institutions to cope with the challenges of the new environment.This paper is based on the work and previous experience of the author and develops some results from the project 'European Comparison of Public Research Systems (EUPSR)', funded by the European Commission TSER programme (contract SOE1-CT96-1036), co-ordinated by J. Senker (SPRU). The author is solely responsible for the work presented in this paper. The support of the EC is gratefully acknowledged as well as that of the Spanish National R&D Plan (SEC97-1382). A preliminary version was presented in the Lisbon Workshop (5-6 June 2000) of the EUROPOLIS project funded by the STRATA Programme

Порядок проектирования пожарной защиты на производстве ККЦ-1

В статье освещается порядок проектирования пожарной защиты в кислородно-конвекторном цехе (ККЦ-1), металлургического предприятия ОАО ЗСМК (Кемеровской обл., г.Новокузнецка).The article covers the order of designing a fire protection at the oxygen-convector workshop of the metallurgical enterprise JSC ZSMK (Kemerovo region, Novokuznetsk city)