Plant Golgi-associated vesicles contain a novel alpha-actinin-like protein

By using Western blotting, immunofluorescence and immunogold labeling, a novel alpha-actinin-like protein was found in pollen and pollen tubes of Lilium davidii, a model system for cytoskeleton and Golgi apparatus study of plant. As measured by Western blotting, the molecular mass of the a-actinin-like protein was about 80 kDa. Under confocal laser scanning microscopy after immunofluorescence labeling, the distribution of the alpha-actinin-like protein appeared punctated in the cytoplasm of the pollen and pollen tubes. When double labeled, the protein was co-localized with Golgi 58K protein. In addition, some fraction of the alpha-actinin-like protein was found to co-distribute with F-actin bundles in the pollen tubes. Additional studies with immuno-gold labeling and transmission electron microscopy revealed that the alpha-actinin-like protein bound mainly to the membranes of Golgi-associated vesicles. When the pollen tubes were treated with Brefeldin A (BFA), the a-actinin-like proteins were dispersed into the cytoplasm, and the growth of pollen tubes was inhibited. After BFA was removed, the protein was reversibly recovered on the Golgi apparatus. These results suggest that the novel alpha-actinin-like protein is a BFA-sensitive protein on the membranes of Golgi-associated vesicles, and may participate in Golgi-associated vesicles budding and/or sorting, together with actin microfilaments.     

Effectiveness of Influenza Vaccination in Patients with End-Stage Renal Disease Receiving Hemodialysis: A Population-Based Study

Background

Little is known on the effectiveness of influenza vaccine in ESRD patients. This study compared the incidence of hospitalization, morbidity, and mortality in end-stage renal disease (ESRD) patients undergoing hemodialysis (HD) between cohorts with and without influenza vaccination.

Methods

We used the insurance claims data from 1998 to 2009 in Taiwan to determine the incidence of these events within one year after influenza vaccination in the vaccine (N = 831) and the non-vaccine (N = 3187) cohorts. The vaccine cohort to the non-vaccine cohort incidence rate ratio and hazard ratio (HR) of morbidities and mortality were measured.

Results

The age-specific analysis showed that the elderly in the vaccine cohort had lower hospitalization rate (100.8 vs. 133.9 per 100 person-years), contributing to an overall HR of 0.81 (95% confidence interval (CI) 0.72–0.90). The vaccine cohort also had an adjusted HR of 0.85 [95% CI 0.75–0.96] for heart disease. The corresponding incidence of pneumonia and influenza was 22.4 versus 17.2 per 100 person-years, but with an adjusted HR of 0.80 (95% CI 0.64–1.02). The vaccine cohort had lowered risks than the non-vaccine cohort for intensive care unit (ICU) admission (adjusted HR 0.20, 95% CI 0.12–0.33) and mortality (adjusted HR 0.50, 95% CI 0.41–0.60). The time-dependent Cox model revealed an overall adjusted HR for mortality of 0.30 (95% CI 0.26–0.35) after counting vaccination for multi-years.

Conclusions

ESRD patients with HD receiving the influenza vaccination could have reduced risks of pneumonia/influenza and other morbidities, ICU stay, hospitalization and death, particularly for the elderly.     

Disappearance of desiccation tolerance of imbibed crop seeds is not associated with the decline of oligosaccharides

The relationship between sugar content and loss of desiccation tolerance of hydrated crop seeds (tomato, okra, snow pea, mung bean, and cucumber) was evaluated by imbibing seeds with or without ABA, followed by dehydration and germination. During the process of hydration, but before the seeds lost desiccation tolerance, monosaccharide content increased only slightly, sucrose increased in snow peas, mung bean and cucumber, but maintained its original level in other species and the oligosaccharides declined dramatically. At the time of losing desiccation tolerance, the sucrose content of imbibed seeds was 2-3 times higher than the original level in most species. Positive significant correlation coefficients (r) were found in many, but not all crop seeds between desiccation tolerance and the oligosaccharide mass, or oligo/sucrose ratio. The ratio of oligo/sucrose in intact seeds at the time of losing desiccation tolerance, however, was not a fixed value and varied among species. Oligosaccharides declined significantly in different seed parts of imbibed cucumber seeds while sucrose increased to a higher level in the radicle than in the hypocotyl. Radicles were far more sensitive to desiccation than hypocotyls. The same observation was found for cucumber seeds imbibed in 100 M ABA, yet desiccation tolerance was largely maintained in hypocotyls and cotyledons. It is concluded that sucrose and oligosaccharides are not the determinants of the loss of desiccation tolerance in hydrated seeds.Imbibed seeds did not show any differences between seed parts in their ability to resynthesize sugars during the process of slow dehydration. Differences in sensitivity to desiccation among seed parts were not due to differences in the initial water content or to the rate of water content increase among seed parts. Physiological regulation of the loss of desiccation tolerance in crop seeds during hydration is discussed.     

Rpn5 is a conserved proteasome subunit and required for proper proteasome localization and assembly

Proper function of the 26 S proteasome requires assembly of the regulatory complex, which is composed of the lid and base subcomplexes. We characterized Rpn5, a lid subunit, in fission yeast. We show that Rpn5 associates with the proteasome rpn5. Deletion (rpn5Delta) exacerbates the growth defects in proteasome mutants, leading to mitotic abnormalities, which correlate with accumulation of polyubiquitinated proteins, such as Cut2/securin. Rpn5 expression is tightly controlled; both overexpression and deletion of rpn5 impair proteasome functions. The proteasome is assembled around the inner nuclear membrane in wild-type cells; however, in rpn5Delta cells, proteasome subunits are improperly assembled and/or localized. In the lid mutants, Rpn5 is mislocalized in the cytosol, while in the base mutants, Rpn5 can enter the nucleus, but is left in the nucleoplasm, and not assembled into the nuclear membrane. These results suggest that Rpn5 is a dosage-dependent proteasome regulator and plays a role in mediating proper proteasome assembly. Moreover, the Rpn5 assembly may be a cooperative process that involves at least two steps: 1) nuclear import and 2) subsequent assembly into the nuclear membrane. The former step requires other components of the lid, while the latter requires the base. Human Rpn5 rescues the phenotypes associated with rpn5Delta and is incorporated into the yeast proteasome, suggesting that Rpn5 functions are highly conserved.     

Induction of prolactin release by LRF and LRF-agonist

Infusion of LRF (0.2 μg/min × 3.5 hrs) and injection of LRF-agonist (50 μg, SC) elicited a prompt and sustained PRL release by the pituitary. This effect is independent of ovarian steroid environment as observed in both normal cycling women and hypogonadal subjects with similar time course and magnitude of PRL release.     

Identification,characterization, and comparison of RNA-degrading enzymes of wheat and barley

RNA-degrading enzymes play an important role in regulating gene expression, and sequence analyses have revealed significant homology among several plant RNA-degrading enzymes. In this study we surveyed crude extracts of the above-ground part of the common wheat (Triticum aestivum L.) and the cultivated barley (Hordeum vulgare L.) for major RNA-degrading enzymes using a substrate-based SDS-PAGE assay. Fifteen wheat and fourteen barley RNA-degrading enzymes, with apparent molecular masses ranging from 16.3 to 40.1 kD, were identified. These RNA-degrading enzymes were characterized by their response to pH changes and addition of EDTA and ZnCl₂ to the preincubation or incubation buffers. The 33.2- to 40.1-kD wheat and barley, 31.7-kD wheat, and 32.0-kD barley enzyme activities were inhibited by both zinc and EDTA and were relatively tolerant to alkaline environment. The 22.7- to 28.2-kD enzymes were inhibited by zinc but stimulated by EDTA. The 18.8-kD enzyme exists in both wheat and barley. It was active in an acid environment, was inhibited by zinc, but was not affected by EDTA. Two enzyme activities (31.0 and 32.0 kD) are unique to the common wheat. Contribution from Agriculture Research Division, University of Nebraska, Journal Series No. 9895.     

Influence of high-fiber diet on bacterial populations in gastrointestinal tracts of obese- and lean-genotype pigs

Bacterial populations from gastrointestinal tracts of genetically lean and obese pigs fed a low- or high-fiber diet (0 or 50% alfalfa meal, respectively) were enumerated with rumen fluid media and specific energy sources. Total culture counts in rectal samples declined 56 (P greater than 0.05) and 63% (P less than 0.05) in lean and obese animals, respectively, 3 weeks after feeding the high-fiber diet. After 8 weeks, culture counts had risen and were similar to those obtained before alfalfa was fed (0 week). At slaughter, 12 to 17 weeks after feeding the high-fiber diet, total counts from rectal samples of lean pigs continued to rise and were 13% greater than the 0-week counts, whereas counts from obese animals declined 37% (P greater than 0.05). The number of cellulolytic bacteria in rectal samples of lean-genotype pigs fed the high-fiber diet increased 80 and 71% from 0 to 3 weeks and 3 to 8 weeks, respectively. This overall increases from 0 to 8 weeks in lean pigs was significant (P less than 0.05); however, these increases were not seen in obese pigs. These data suggest that the microflora is initially suppressed when exposed to a high-fiber diet and that later some adaptation takes place, apparently more so in lean than in obese pigs. When specific energy sources were used to delineate the distribution of different bacterial populations in the cecum, colon, and rectum, trends could be detected between high- and low-fiber diets. These data also support the concept that bacteria populations from different sites in the large bowel differ.     

Stimulation of cyclic AMP and lipolysis in adipose tissue of normal and obese Avy/a mice by LY79771, a phenethanolamine,and stereoisomers

The stimulation of cyclic AMP and lipolysis by LY79771, a phenethanolamine antiobesity compound, and its 3 stereoisomers in adipose tissue of obese viable yellow mice and normal mice were studied. Both activities were stereo-specific with LY79771, the R,S isomer, and LY79730, the R,R isomer, being more potent than LY103085, the S,S isomer, and LY103672, the S,R isomer. Propranolol, a nonspecific β-antagonist, completely inhibited the elevation of cyclic AMP and lipolysis whereas atenolol, a specific β₁ antagonist, inhibited the elevation of cyclic AMP but did not completely inhibit lipolysis. These findings indicate that the elevation of cyclic AMP was mediated by the β₁- receptor whereas the stimulation of lipolysis was mediated by both the β₁ and β₂ receptors. The adipose tissue of the obese viable yellow mice responded to these compounds less than that of the normal mice.     

Characteristics of the binding of the anticancer agents mitoxantrone and ametantrone and related structures to deoxyribonucleic acids

The binding constants for interaction of the anticancer agents mitoxantrone and ametantrone and several congeners with calf thymus DNA and the effects of ionic strength changes have been determined spectrophotometrically. The agents show a preference for certain sequences, particularly those with GC base pairs, and the magnitude of the specificity depends on the specific substituents on the anthraquinone ring system. The binding constant for mitoxantrone with calf thymus DNA in 0.1 M Na+, pH 7, is approximately 6 X 10(6) M-1, and the rate constant for the sodium dodecyl sulfate driven dissociation of mitoxantrone from its calf thymus DNA complex under the same solution conditions and 20 degrees C was determined to be 1.3 s-1. The unwinding angle of mitoxantrone determined independently by viscosity measurements and by a novel assay employing calf thymus topoisomerase shows excellent agreement for a value of 17.5 degrees. The viscosity increase of sonicated calf thymus DNA varies considerably with the substituent on the anthraquinone ring system. Binding studies employing T4 and phi w-14 DNAs in which the major groove is occluded and the reverse experiment with anthramycin-treated calf thymus DNA indicate at least part of the mitoxantrone molecule may lie in the minor groove.