AtPNP-A is a systemically mobile natriuretic peptide immunoanalogue with a role in Arabidopsis thaliana cell volume regulation.

Cellular and physiological evidence suggests the presence of a novel class of systemically mobile plant molecules that are recognized by antibodies against vertebrate atrial natriuretic peptides (ANPs). In order to characterize the function of these immunoanalogues we have expressed the full-length recombinant (AtPNP-A[1-126]) and demonstrate that this molecule induces osmoticum-dependent H(2)O uptake into protoplasts at nanomolar concentrations and thus affects cell volume. A similar response is also seen with a recombinant that does not contain the signal peptide (AtPNP-A[26-126]) as well as a short domain (AtPNP-A[33-66]) that shows homology to the vertebrate peptide.

Chronic renal failure and anterior hypophysial hormones.

Kidneys are not only organs with an excretory function but they produce their own endocrine factors which are involved in supporting homeostasis in the organism. The kidneys are the organs in which metabolism and biodegradation of many hormones take place. Together with the liver, the kidneys actively take part in the catabolism of hormones.

Influence of dopamine energic pharmacology drugs on secretion of the adrenocorticotropic hormone from the hypophysis.

To elucidate the role of dopamine as a neuromediator in the adrenocorticotropic hormone (ACTH) secretion, investigations were carried out with dopaminergic pharmacology drugs on male white Wistar rats. In the first series of experiments, the effects of 200 mg/kg body wt L-DOPA, of the combination of 200 mg/kg L-DOPA and 50 mg/kg body wt carbidopa, and of 2.5 mg/kg body wt bromocriptine, after a single intraperitoneal injection of ACTH in the serum of rats after 30, 90 and 120 min, following the injection, were studied.

Effect of cryopreservation on lipids and some physiological features of spermatozoa from rams pastured in highlands and in valleys.

The effect of low temperature preservation on the motility and morphology of acrosomes, acrosomal proteolytic activity, phospholipid and fatty acid composition of phosphatidyl choline (PC) and phosphatidyl ethanolamine (PE), and the cholesterol/phospholipid molar ratio in sperm from rams housed in the highlands or in the valleys, were studied. The indices of motility and morphological integrity of sperm from highland rams were much greater compared with those of valley rams. Phosphatidyl choline (PC) of the highland rams was more unsaturated, while PE was more saturated compared with those of valley rams.

Isolation of an osmotolerant ale strain of Saccharomyces cerevisiae.

Saccharomyces cerevisiae (ale strain) grown in batch culture to stationary phase was tested for its tolerance to heat (50 degrees C for 5 min), hydrogen peroxide (0.3 M) and salt (growth in 1.5 M sodium chloride/YPD medium).

The effect of magnesium ions during beer fermentation.

When cells of Saccharomyces cerevisiae ale strain C1028 were grown aerobically, ethanol production displayed a hyperbolic increase over a limited range of magnesium concentrations up to approximately 0.7 mM. Entry of cells into the stationary growth phase and the time of maximum ethanol and minimum sugar concentrations correlated with a period of maximum Mg2+ concentration in the growing media.

The effect of prostaglandin E1 on in vitro transcription of sperm chromatin, isolated from patients with azoospermia, teratospermia and chronic prostatitis.

We have investigated the influence of Prostaglandin E1 on the in vitro transcription of chromatin, isolated from spermatozoa of patients suffering from different pathologies, leading to infertility, namely, azoospermia, teratospermia and chronic prostatitis. Our studies indicate that prostaglandin E1 has a stimulatory effect both on in vitro transcription, on the number of RNA polymerase molecules and the polyribonucleotide elongation rates as compared to sperm chromatin from healthy patients. The results on the incorporation of alpha-32P-ATP in to RNA in the presence and absence of Prostaglandin E1 correlate well with the data on the number of actively transcribing RNA polymerase molecules and the rate of RNA elongation, which might be due to low levels of prostaglandin E1 in human semen.

Alternative splicing of the rabbit beta-globin pre-mRNA in vivo after transient transfection of myoblast and myotube cells.

The relationship between preferences among alternative 5' splice sites and their sequences was investigated using as model mouse myoblasts and myotubes after transient transfection with the rabbit beta-globin gene. The preferences for the use of two different 5' splice sites, acting with different efficiencies to direct splicing in vivo are reported. The predominant selection of the upstream splice site has been shown in normal mouse myoblasts.

Isolation of a heat-labile protein factor involved in the 3'-processing of H4 pre-mRNA.

It is well documented that the snRNP particles play a role in the processing of histone pre-mRNAs. There is also evidence that in addition to the snRNP particles, at least two more proteins are involved in the vitro 3'-processing of histone pre-mRNAs. The aim of the present work was the isolation and purification of one of these PF250 factors.

The influence of prostaglandin E1 on in vitro transcription of sperm chromatin from healthy males.

Run-on transcription experiments with sonicated chromatin from healthy individuals in the presence and absence of prostaglandin E1 showed different levels of transcription. Thus the level of incorporation of 14C-UTP into pre-mRNA proved to be about twice as high in the presence of postaglandin E1 as in the controls. The kinetic data of the in vitro transcription indicated that there were two peaks of incorporation of 14C-UTP into RNA both in the controls and in prostaglandin E1 treated probes but at different time intervals.

Quantification of actively transcribing RNA polymerase B molecules in human sperm chromatin and the effect of prostaglandin E1.

Run-on transcription experiments with sonicated chromatin from spermatozoa of healthy men revealed the presence of in vitro transcription. The number of actively transcribing RNA polymerase B molecules in sperm chromatin in vitro, isolated from healthy individuals, and the effect of prostaglandin El, were investigated. The results indicate that the number of RNA polymerase B molecules actively engaged in transcription increased one and a half times when 5 units of prostaglandin E1 was added to the reaction mixtures.

Immunofluorescent study after transient transfection of myoblast cells with the plasmid PSV40-beta-globin.

The level of transfection of myoblast C-2/C-12 cells with the plasmid PSV40-beta-globin, using the immunofluorescence assay, was investigated. Myoblasts, which are non-terminally differentiated cells, were chosen since it is known that terminally differentiated myotubes are very poorly transfected. The results showed that myoblast cells of the C-2/C-12 cell line were readily transfected within 24 h with the PSV40-beta-globin gene.

Influence of freezing at different temperatures on the transcription activity of buffalo sperm chromatin.

The effect of freezing at different temperatures, -20 degrees C, -70 degrees C and -196 degrees C, on the transcription activity of buffalo sperm chromatin was investigated. The kinetic data of incorporation of 3H-UTP in pre-mRNA indicate that temperatures of -70 degrees C and -196 degrees C are the most favourable for preservation, since transcription activity gradually increases with time, reaching maximum values within 30 min. Freezing at -20 degrees C or preservation at 4 degrees C leads to a rapid decrease of transcriptional activity within 10 and 20 min, respectively.

Electron microscopic data for the presence of post-meiotic gene expression in isolated ram sperm chromatin.

A whole mount electron microscopic technique facilitated a direct visualization of transcripts in ram spermatozoa in run-on experiments. The localization of transcripts in sperm chromatin by spreading enabled identification of regions where transcription complexes, presumably pre-mRNA species, were seen related to chromatin. In another series of experiments the localization of polymerase II was demonstrated using a specific antibody against the conservative tail domain of the polymerase II molecule, followed by protein A-gold visualization on spread chromatin and on thin sections from mature spermatozoa.

Electron microscopic demonstration of transcription of ram sperm chromatin.

Transcription of ram sperm chromatin was examined by two electron microscopic techniques, namely spreading and thin sections. Labelling by Streptavidin-gold particles permits identification of transcription complexes, that have previously incorporated biotinylated uridine triphosphate. This supports previous electron microscopic data for randomly distributed transcription complexes and the presence of polymerase II molecules, documented by means of specific antibody using immunoelectron microscopy.

Isolation and purification of U7 snRNP particles.

1. A procedure has been developed for the isolation of U7 small nuclear ribo-protein particles involved in the processing of histone pre-mRNAs. They were fractionated from the rest of the snRNPs through a series of gel filtration and affinity chromatography steps.

The effect of three cryoprotective diluents on the in vitro transcription of ram sperm cells.

The effect of three different solvents was investigated in run-on experiments, using purified ram sperm nuclei. The best cryoprotective diluent proved to be Nagase-Niwa, which had the most positive effect on transcription. The kinetic data of incorporation of 32P-ATP in pre-mRNA indicated that there was a stepwise increase in the level of transcription during the first 20 min of incubation, being lowest in the control and highest in the presence of the diluent Nagase-Niwa.

Isolation and purification of U7 and snRNP particles.

A procedure was developed for the isolation of U7 small nuclear ribonucleoprotein particles involved in the processing of histone pre-mRNAs. U7 snRNP particles were fractionated from the rest of the snRNPs by means of a series of gel filtration and affinity chromatography steps. The isolated assembly of U7 snRNP particles appeared to be intact and pure as judged by gel electrophoresis of their RNA.

Characterization of the protein moiety of U7 small nuclear RNP particles.

U7 snRNP particles contain a set of seven proteins with molecular weights in the range of 13.5 to 50 kD. One protein with a molecular weight of 18 kD carried the antigenic determinant responsible for the interaction of U7 snRNPs with autoantibodies from patients with connective tissue diseases.

U7 snRNP particles bind H4 pre-mRNA in vitro.

1. U7 snRNP particles were bound in vitro to H4 pre-mRNA using immunoassay experiments. 2.

3' processing of histone H4 precursor mRNA requires the presence of a small nuclear RNP particle.

1. Incubation of in vitro synthesized mouse histone H4 mRNA precursors in nuclear extracts of mouse 3T6 fibroblasts, rat L6-5 myoblasts and myotubes yields processed mRNA species. A processing activity was identified in all three kinds of extracts that cleaves the precursor transcripts, generating mRNA species with mature 3' termini.

Chronic ethanol treatment of rats reduces RNA polymerase activity in isolated liver nuclei.

The effect of acute and chronic ethanol treatment of rats on the activity of RNA polymerases I and II in isolated nuclei has been studied. Results indicate that acute ethanol administration does not change the activity of the nuclear RNA polymerases while chronic ethanol treatment significantly reduces the activity of both RNA polymerases I and II.

U5 snRNP particles bind pre-messenger RNA in vitro.

The ability of purified U5 small nuclear RNP particles (U5 snRNPs) to bind in vitro pre-mRNA of the human beta-globin gene was investigated. The transcript which contained sequences, corresponding to the second intron and fragments of the second and third exons of the gene was bound to U5 snRNP particles in the presence of antibodies specific against U5 snRNPs. The in vitro splicing of pre-mRNA was inhibited in the presence of autoantibodies against U5 snRNP particles.

Isolation of U5 snRNP particles.

A method for the isolation of intact U5 small nuclear RNP particles from HeLa cells has been developed. The procedure includes nuclear extraction of the particles at moderate ionic strength, fractionation in agarose gels, electrophoretic transfer on DEAE cellulose paper and elution with ammonium chloride. The purified U5 snRNP particles contain U5 RNA and a set of eleven proteins.

U4 and U6 small nuclear ribonucleoprotein particles. 1. Fractionation and characterization of snRNPs containing U4 and U6 RNAs.

The isolation of U4 and U6 small nuclear ribonucleoprotein particles (snRNP) was undertaken, since there has been no reliable method for their fractionation established. The procedure subjects a nuclear extract from HeLa cells to several types of ion exchange chromatography at moderate ionic strength, electrophoresis on agarose gels, transfer of the particles on DEAE cellulose paper, and elution with ammonium chloride. The purified U4 and U6 snRNPs contain U4 and U6 RNAs, respectively, and a set of six polypeptides, present in U4 RNPs and seven polypeptides in U6 snRNP particles.