RNA polymerase II C-terminal repeat influences response to transcriptional enhancer signals

The large subunit of RNA polymerase II contains a highly conserved and essential heptapeptide repeat (Pro-Thr-Ser-Pro-Ser-Tyr-Ser) at its carboxy terminus. Saccharomyces cerevisiae cells are inviable if their RNA polymerase II large subunit genes encode fewer than 10 complete heptapeptide repeats; if they encode 10 to 12 complete repeats cells are temperature-sensitive and cold-sensitive, but 13 or more complete repeats will allow wild-type growth at all temperatures. Cells containing C-terminal domains (CTDs) of 10 to 12 complete repeats are also inositol auxotrophs. The phenotypes associated with these CTD mutations are not a consequence of an instability of the large subunit; rather, they seem to reflect a functional deficiency of the mutant enzyme. We show here that partial deletion mutations in RNA polymerase II CTD affect the ability of the enzyme to respond to signals from upstream activating sequences in a subset of promoters in yeast. The number of heptapeptide repeats required for maximal response to signals from these sequences differs from one upstream activating sequence to another. One of the upstream elements that is sensitive to truncations of the CTD is the 17-base-pair site bound by the GAL4 transactivating factor.     

Improved business planning through an awareness of political cycles

Can business planning be improved if more attention is paid to underlying political cycles? This paper compares practitioner and researcher perspectives on this issue. While practioners stand to gain useful insights from a careful examination of past political cycles, these insights may be disconfirmed by rigorous tests carried out by researchers. In this paper we isolate and examine five hypotheses from the literature on the political-economic cycle.     

The mechanism of tetrodotoxin on the in situ acetylcholinesterase in the vagal heart system ofRana pipiens

Zusammenfassung Am isolierten Vagus-Herzen vonRana pipiens wird die Wirkung der Vagusreizung gemessen: Konzentrationen unter 4×10^–10 g/ml Tetrodotoxin erhöhen die vagale Reizungswirkung, nicht aber die Herzkontraktionen.     

Ganglioside-induced differentiation-associated protein-1 is mutant in Charcot-Marie-Tooth disease type 4A/8q21.

We previously localized and fine-mapped Charcot Marie Tooth 4A (CMT4A), the autosomal recessive, demyelinating peripheral neuropathy, to chromosome 8. Through additional positional cloning, we have identified a good candidate gene, encoding ganglioside-induced differentiation-associated protein-1 (GDAP1). We found three different mutations in four different Tunisian families-two nonsense and one missense mutation. How mutations in GDAP1 lead to CMT4A remains to be understood.     

Antifungal properties of taxol and various analogues

The antimitotic agent taxol was tested for toxicity towards fungi from different taxonomic groups and found to be particularly active against oomycete fungi. In germinating zoospore cysts of the oomycetePhytophthora capsici the mechanism of action of taxol was shown to involve inhibition of mitosis, presumably resulting from an effect on microtubules. Various taxol analogues with deleted A-ring C-13 side chain substituents were tested for toxicity towardsP. capsici andAphanomyces cochlioides to provide insight into structural features required for activity. The importance of the side chain was shown by the much lower activity as compared to taxol of analogues lacking all or part of the side chain. The effect of stereochemistry at the C-2 position on fungitoxicity towards oomycetes was similar to that reported previously on mammalian microtubule assembly.     

Identification of ϱ-antigenic determinants on the surface,of mouse T-lymphocytes

Summary A monospecific antiserum has been prepared in rabbits against purified -antigen, a 100,000 mol.wt glycoprotein found on the surface of mouse L-cells. This antiserum has been employed to demonstrate the presence of -antigenic determinants selectively on the surface of mouse T-, but not B-lymphocytes.We thank Drs A. Christopher and R. Hunt for advice during the course of these studies. This work was supported by grants from the U.S. Public Health Service and the American Cancer Society.     

Methyl cellosolve-induced sensitization of mice to bacterial endotoxin

Summary Treatment of mice with a sublethal dose of methyl cellosolve renders the animals 64-fold more sensitive to the toxic effects of bacterial endotoxin.Acknowledgments. I would like to thank Mr Larry Davis for his excellent technical assistance in these studies.This work was supported by the Naval Medical Research and Development Command, Research Work Unit No. MF585240013.1026. The opinions and assertions contained herein are the private ones of the writer and are not to be construed as official or reflecting the views of the Navy Department or the naval service at large. The experiments conducted herein were conducted according to the principles set forth in the Guide for the Care and Use of Laboratory Animals, Institute of Laboratory Resources, National Research Council.     

Extension of the rice DH population genetic map with microsatellite markers

Genetic mapping of microsatellite markers was carried out in a rice DH population derived from across between Zaiyeqing 8 (indica) and Jingxi 17 (japonica). A total of 89 microsatellite markers, including 84 (GA)_n, 2(TCT)_n, 2(ATT)_n, and, l(ATC)_n motifs, were integrated relatively evenly into the established genetic map of the DH population. This will facilitate the utilization of microsatillite markers in rice gene mapping and marker aided breeding.     

Meaningfulness: A Third Dimension of the Good Life

This paper argues that an adequate conception of a good life should recognize, in addition to happiness and morality, a third dimension of meaningfulness. It further proposes that we understand meaningfulness as involving both a subjective and an objective condition, suitably linked. Meaning arises when subjective attraction meets objective attractiveness. In other words one’s life is meaningful insofar as one is gripped or excited by things worthy of one’s love, and one is able to do something positive about it. The paper concludes with some speculations about how this conception of meaningfulness might help to explain the conditions under which social volunteering can be especially rewarding.     

Optimum ordering policy for preventive age replacement

Most of the spare ordering policies treated up to now have assumed that preventive and corrective replacement costs are equal, which implies in essential that there is no significant need for preventive replacement. This paper presents an ordering policy for preventive age replacement with minimal repair. Introducing the replacement, repair, inventory holding and shortage costs, the expected cost rate is derived. A procedure to determine jointly the ordering time for a spare and the preventive replacement time for the operating unit so as to minimize the expected cost rate is proposed. To explain the ordering policy and the optimization procedure, a numerical example is also included.