Tolerance of Ambiguity: Text Analytic vs Self-Report Measures in Two Nonclinical Groups

Avoidance of ambiguity can be examined by both text analytic and self-report methods. In previous studies using text analytic methods, clinical groups showed a higher avoidance of ambiguity than nonclinical subjects. In nonclinical subjects, however, higher avoidance of ambiguity did not correlate with emotional processes. In these studies, higher avoidance of ambiguity was assessed by a text analytic method (DoTA), which was applied to the Holtzman Inkblot Technique. However, the Inkblot Technique may not activate those cognitive-affective structures in nonclinical subjects required to elicit higher avoidance of ambiguity. Thus, the following discrepant results can be predicted: in nonclinical subjects, DoTA indicators of higher avoidance of ambiguity based on Holtzman Inkblot Technique do not show correlations with self-report measures of higher avoidance of ambiguity such as the Ambiguity Tolerance Questionnaire, the Inventory for the Measurement of Tolerance of Ambiguity (Reis inventory), or self-report measures of related traits of personality such as the Giessen Test. Self-report measures of higher avoidance of ambiguity should show such correlations. Two studies were carried out to test these hypotheses. In Study 1, 80 nonclinical subjects (48 women, M age = 34.5 yr.) were examined using the DoTA text analytic method, the Ambiguity Tolerance Questionnaire-14 and the Giessen Test. In Study 2, 82 nonclinical subjects (43 women, M age = 34.0 yr.) were tested using the Reis inventory. The results obtained in these subjects are consistent with the hypothesis.

The role of lipocalins in airway disease

The pathogenesis of allergic airway inflammation and disease is complex and still not fully understood. Many cells, factors and mediators are involved in the different aspects of induction, maintenance and persistence of airway inflammation. The heterogeneity and redundancy of this system is one of the main reasons why novel therapeutic targets focusing on the pathogenesis of asthma only hesitantly reach the market and clinical application. Thus, it seems mandatory that we proceed in our efforts to better understand this micro cosmos to succeed in the development of safe and effective drugs for the treatment of more severe and refractory forms of asthma and chronic obstructive pulmonary disease. One of the more recently discovered mediators in the context of airway inflammation are the lipocalins (Lcns). They are a family of proteins that share functional and structural similarities and are involved in the transport of small hydrophobic molecules such as steroids and lipids into the cell. Lcns are found in many different cell types from plants and bacteria through invertebrate cells to cells of vertebrate origin. The purpose of this review is to summarize the role of Lcns in airway diseases, focusing on allergic and infectious inflammation. In particular, we will summarize the present knowledge about Lipocalin 1 and Lipocalin 2, where exciting new discoveries in the recent years have highlighted their role in pulmonary disease and infection. This new class of proteins is another putative candidate for the development of novel drugs against airway inflammation.

Interactions between Spc2p and other components of the endoplasmic reticulum translocation sites of the yeast Saccharomyces cerevisiae

In yeast, the endoplasmic reticulum membrane proteins Sec11p and Spc3p are essential for the cleavage of signal peptides of nascent polypeptide chains during their passage through translocation sites. Genetic and biochemical experiments demonstrate that Sec11p and Spc3p are tightly associated with two other proteins, Spc1p and Spc2p, whose functions are largely unknown. Using anti-Spc2p antibodies, we show here that this heterotetrameric complex associates with Sbh1p and Sbh2p, the beta-subunits of the Sec61p complex and the Ssh1p complex, respectively. Depletion of Spc2p decreased the enzymatic activity of the SPC in vitro, led to a loss of Spc1p, and led to a down-regulation of the amount of Sec11p and Spc3p in the endoplasmic reticulum. Moreover, the deletion of Spc2p also decreased the expression level of Sbh2p. These data implicate that Spc2p not only enhances the enzymatic activity of the SPC but also facilitates the interactions between different components of the translocation site.

Mammalian Sec61 is associated with Sec62 and Sec63

In yeast, efficient protein transport across the endoplasmic reticulum (ER) membrane may occur co-translationally or post-translationally. The latter process is mediated by a membrane protein complex that consists of the Sec61p complex and the Sec62p-Sec63p subcomplex. In contrast, in mammalian cells protein translocation is almost exclusively co-translational. This transport depends on the Sec61 complex, which is homologous to the yeast Sec61p complex and has been identified in mammals as a ribosome-bound pore-forming membrane protein complex. We report here the existence of ribosome-free mammalian Sec61 complexes that associate with two ubiquitous proteins of the ER membrane. According to primary sequence analysis both proteins display homology to the yeast proteins Sec62p and Sec63p and are therefore named Sec62 and Sec63, respectively. The probable function of the mammalian Sec61-Sec62-Sec63 complex is discussed with respect to its abundance in ER membranes, which, in contrast to yeast ER membranes, apparently lack efficient post-translational translocation activity.

Mood influences on automatic and controlled semantic priming

Mood effects on automatic and controlled components of semantic priming were examined. After a neutral or positive mood manipulation, subjects underwent two blocks of a priming task. Automatic and strategic priming processes were operationally differentiated by the assumption that automatic priming remains constant during the task, whereas controlled priming develops slowly during the course of the experiment. In the first block the priming effect was greater for happy than for neutral mood participants. In the second block the priming effect was greater for neutral mood than for happy participants. The results confirm the hypothesis of a mood-dependent processing change: During early trials priming is based on automatic processing facilitated by positive mood. This processing mode is later superseded by controlled processes aided by neutral mood.

The yeast SPC22/23 homolog Spc3p is essential for signal peptidase activity

In eucaryotic cells signal sequences of secretory and membrane proteins are cleaved by the signal peptidase complex during their transport into the lumen of the endoplasmic reticulum. The signal peptidase complex in yeast consists of four subunits. To date, three of these subunits have been functionally characterized. One of them, the Sec11p, is essential for viability of yeast cells. It shows significant homology to the mammalian SPC18 and SPC21 as well as to bacterial leader peptidases. Two other subunits, Spc1p and Spc2p, have been shown to be homologous to mammalian SPC12 and SPC25, respectively, and are not essential for protein translocation or signal peptide cleavage. We have purified and analyzed the fourth subunit of yeast signal peptidase, Spc3p. The protein is essential for viability of yeast cells. Depletion of SPC3 leads to accumulation of precursors of secretory proteins in vivo and to the loss of the signal peptidase activity in vitro. Therefore, in contrast to the bacterial leader peptidases, yeast signal peptidase requires a second subunit for its function.

Structurally related Spc1p and Spc2p of yeast signal peptidase complex are functionally distinct

Two subunits of the mammalian signal peptidase complex, SPC12 and SPC25, share similar membrane topologies with the majority of each protein oriented toward the cytoplasm. Such similarities may suggest that these proteins perform redundant functions in signal peptidase activity. In the present study, we addressed this issue through analysis of the yeast homologs to SPC12 and SPC25, Spc1p and Spc2p. We show that both Spc1p and Spc2p are nonessential for signal peptidase activity and growth of yeast cells and that null mutations in the genes encoding Spc1p and Spc2p are synthetically lethal with a conditional mutation affecting Sec11p, an essential subunit of yeast signal peptidase. However, a high copy plasmid encoding Spc1p suppresses the conditional sec11 mutation, whereas the corresponding plasmid encoding Spc2p does not suppress sec11. Moreover, Spc2p, but not Spc1p, is important for signal peptidase activity and cell viability at high temperatures. These results indicate that although both Spc1p and Spc2p are noncatalytic, they are functionally distinct. Evidence is also presented that a double mutant lacking Spc1p and Spc2p grows well relative to wild type yeast cells, indicating that the signal peptidase complex missing at least two of its subunits is sufficient for signal peptidase activity in vivo.

Effects of antisense DNA against the alpha-sarcin stem-loop structure of the ribosomal 23S rRNA

Antisense DNAs complementary against various sequences of the alpha-sarcin domain (C2646-G2674) of 23S rRNA from Escherichia coli were hybridized to naked 23S rRNA as well as to 70S ribosomes. Saturation levels of up to 0.4 per 70S ribosome were found, the identical fraction was susceptible to the attack of the RNase alpha-sarcin. The hybridization was specific as demonstrated with RNase H digestion, sequencing the resulting fragments and blockage of the action of alpha-sarcin. The RNase alpha-sarcin seems to approach its cleavage site from the 3' half of the loop of the alpha-sarcin domain. Hybridization is efficiently achieved at 37 degrees C and can extend at least into the 3' strand of the stem of the alpha-sarcin domain. However, the inhibition of alpha-sarcin activity is observed at 30 degrees C but not at 37 degrees C. For a significant inhibition of poly(Phe) synthesis the temperature had to be lowered to 25 degrees C. The results imply that the alpha-sarcin domain changes its conformation during protein synthesis and that the conformational changes may include a melting of the stem of the alpha-sarcin domain.