Actinomycin D stimulated phaseollin production in endocarp tissues of the French bean (Phaseolus vulgaris L.), maximum production being obtained with 25 to 30 micrograms per milliliter of antibiotic. Under these conditions, net incorporation of (3)H-uridine into total cell ribonucleic acid was inhibited by more than 80% over a 6-hour induction period. If allowance was made for a 2-hour lag in t...

The rat mammary gland has a high content of ribonucleic acid during late pregnancy when the gland is functionally inactive (Greenbaum & Slater, 1957b). Slater (1956) suggested that this high level of ribonucleic acid might result from a very low activity of nucleic acid-degrading enzymes (ribonucleases) during late pregnancy. Rat mammary gland contains high concentrations of heavymetal ions, e....

Since the discovery by Jones (1) of a thermostable enzyme in the pancreas, capable of hydrolyzing ribonucleic acid without the release of either phosphoric acid or purine bases, the evidence as to the nature of its action has been extremely conflicting. Jones and Perkins isolated four mononucleotides from enzyme-treated nucleic acid and concluded that the action of the enzyme consisted in break...

It was first observed by Kozloff (1) that the deoxyribonuclease activity of cell-free extracts of Escherichiu coli could be increased by treatment with pancreatic ribonuclease. This stimulation was found to result from the destruction by the ribonuclease of an inhibitory ribonucleic acid. The phenomenon of cellular deoxyribonuclease inhibition is a widespread one, having been observed in yeast ...

OBJECTIVE We determined the relative abundance of prostaglandin endoperoxide H synthase type 1 and type 2 messenger ribonucleic acid levels in the human fetus and newborn infant. STUDY DESIGN We used ribonuclease protection assays and normalized values to messenger ribonucleic acid of cyclophilin. Tissues were obtained from all 3 trimesters and in the first 9 days of the newborn period. RES...

1. Rat-liver microsomes, ribonucleoprotein particles and a fraction mainly consisting of microsomal membranes were tested for their ability to incorporate amino acids into protein in the presence of ATP, GTP, phosphoenolpyruvate and pyruvate kinase. Addition of polyuridylic acid or of ribonucleic acid from rat-liver nuclei stimulated the incorporating activities. 2. These protein-synthesizing s...

It has been known for several years that deoxyribonucleic acid may normally contain 5-methylcytosine (Wyatt, 1951), 5-hydroxymethylcytosine (Wyatt & Cohen, 1953), and 6-methylaminopurine (Dunn & Smith, 1955, 1958a) in addition to adenine, guanine, cytosine and thymine. The first evidence of such additional bases naturally present in ribonucleic acid is the recent isolation of an unidentified nu...

Recent studies (l-3) from this laboratory showed that the rate and extent of amino acid incorporation into protein by rat prostatic ribosomes decreased shortly after castration. This decrease is reversed by administration of testosterone to the orchiectomized animals. It was suggested that the levels of template ribonucleic acid’ associated with prostatic ribosomes are under the control of test...