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A Soltyk

Publications and source records attributed to A Soltyk.

6 recordsLinked to original sources
PubMed1989

PRP4 (RNA4) from Saccharomyces cerevisiae: its gene product is associated with the U4/U6 small nuclear ribonucleoprotein particle.

The PRP4 (RNA4) gene product is involved in nuclear mRNA processing in yeast cells; we have previously cloned the gene by complementation of a temperature-sensitive mutation. Sequence and transcript analyses of the cloned gene predicted the gene product to be a 52-kilodalton protein, which was confirmed with antibodies raised against the PRP4 gene product. These antibodies inhibited precursor mRNA splicing in vitro, demonstrating a direct role of PRP4 in splicing. Immunoprecipitations with the antibodies indicated that the PRP4 protein is associated with the U4/U6 small nuclear ribonucleoprotein particle.

Amino Acid Sequence↗
PubMed1976

Discrimination of competent Bacillus subtilis with respect to ribonucleic acids.

A study has been made of the affinity of double-stranded helical RNA for DNA receptors in competent Bacillus subtilis. In competition experiments, using homologous and heterologous DNA samples which had been sheared to molecular weights comparable to that of the RNA (about 2 x 10(6)), and which still exhibited appreciable competition in DNA uptake experiments, the replicative form of phage f2 RNA showed no evidence of affinity for receptor sites. A second double-stranded RNA preperation from a widely different source, a mycophage of Penicillium chrysogenum, behaved similarly to the f2 RNA. Transfer RNA and 23S ribosomal RNA, which reduce transformation frequencies in pneumococcus, did not compete for B. subtilis receptors. Lack of competition was not due to enzymatic degradation of the RNA, since the latter was recovered intact following exposure to competent cells. Under conditions where homologous native DNA undergoes normal uptake, there was virtually no uptake of native double-stranded RNA. The results are examined in the light of reports on transformation by RNA and DNA-RNA hybrids, and also in relation to the characterization of the specificity of cell-nucleic acid interactions.

Bacillus subtilis↗
PubMed1975

Fate of heterologous deoxyribonucleic acid in Bacillus subtilis.

CsCl density gradient fractionation of cell lysates was employed to follow the fate of Escherichia coli, phage T6, and non-glucosylated phage T6 deoxyribonucleic acid (DNA) after uptake by competent cells of Bacillus subtilis 168 thy minus trp minus. Shortly after uptake, most of the radioactive Escherichia coli or non-glucosylated T6 DNA was found in the denatured form; the remainder of the label was associated with recipient DNA. Incubation of the cells after DNA uptake led to the disappearance of denatured donor DNA and to an increase in the amount of donor label associated with recipient DNA. These findings are analogous to those previously reported with homologous DNA. By contrast, T6 DNA, which is poorly taken up, appeared in the native form shortly after uptake and was degraded on subsequent incubation. The nature of the heterologous DNA fragments associated with recipient DNA was investigated with Escherichia coli 2-H and 3-H-labeled DNA. Association of radioactivity with recipient DNA decreased to one-fourth in the presence of excess thymidine; residual radioactivity could not be separated from recipient DNA by shearing (sonic oscillation) and/or denaturation, but was reduced by one-half in the presence of a DNA replication inhibitor. Residual radioactivity associated with donor DNA under these conditions was about 5% of that originally taken up. Excess thymidine, but not the DNA replication inhibitor, also decreased association of homologous DNA label with recipient DNA; but, even in the presence of both of these, the decrease amounted to only 60%. It is concluded that most, or all, of the Escherichia coli DNA label taken up is associated with recipient DNA in the form of mononucleotides via DNA replication.

Bacillus subtilis↗
PubMed1975

Heterologous deoxyribonucleic acid uptake and complexing with cellular constituents in competent Bacillus subtilis.

With competent cultures of Bacillus subtilis the uptake of Escherichia coli deoxyribonucleic acid (DNA) is about 50% that for homologous DNA. Uptake of phage T6 DNA, if any, is of the order of 7%, while nonglucosylated phage T6 (T6) DNA is taken up almost as effectively as homologous DNA. Both T6 and T4 DNA interfere only minimally with uptake of homologous DNA; by contrast, T6 DNA competes with homologous DNA as effectively as the latter itself. These results indicate that the glucose residues in the T-even phage DNA, located in the large groove of the DNA helix, reduce affinity for cellular receptors, leading to low binding of T6 DNA. The latter DNA is considerably less degraded by extracellular nucleases than homologous DNA, thus excluding enzymatic hydrolysis as the source of poor uptake. Affinity of DNA for competent cells was also evaluated by the formation, and detection in a CsCl density gradient, of complexes of DNA with cellular constituent(s). Such comlexes, similar to those previously observed with transforming DNA, are formed by E. coli DNA and T6 DNA; in reconstruction experiments the denatured forms of these same DNA samples form complexes when added to the cells before lysis. T6 DNA, on the other hand, does not form such a complex. The possible role of such complexes in transport of DNA to the cell interior is discussed.

Bacillus subtilis↗
PubMed1975

Competitive inhibition of transformation in group H Streptococcus strain Challis by heterologous deoxyribonucleic acid.

Glucosylated deoxyribonucleic acid (DNA) from phages T4 and T6 competes poorly with homologous DNA causing only a slight decrease of transformation in Group H Streptococcus strain Challis. Other types of heterologous DNAs (Micrococcus luteus, Clostridium perfringens, Escherichia coli, calf thymus and non-glucosylated phage T6 DNA), in contrast to glucosylated T4 and T6 DNAs, compete with transforming DNA to the normal, high extent. These results indicate that as in transformation of Bacillus subtilis, the presence of glucose attached to 5-hydroxymethylcytosine in phage T6 DNA considerably decreases the interaction of such DNA with competent cells of the Challis strain. It also indicates that the guanine plus cytosine content of DNA is not decisive in determining its interaction with competent cells.

Animals↗