The behaviour of acid-soluble DNA precursors in synchronized and asynchronously growing yeast after X-irradiation is investigated by labeling techniques with 32P; and by enzymic estimation. In prelabeled synchronized growing cells, radioactivity associated with deoxynucleoside triphos­ phates increases to maximum values shortly before each DNA replication, followed by a drastic decrease during ...

Nuclear transport as well as reassembly of the nuclear envelope (NE) after completion of mitosis are processes that have been shown to require GTP and ATP. To study the presence and localization of GTP-binding proteins in the NE, we have combined complementary techniques of [alpha-32P]GTP binding to Western-blotted proteins and UV crosslinking of [alpha-32P]GTP with well-established procedures ...

A general two step procedure for the internal labeling of L-deoxyoligonucleotides, Spiegelmers, has been developed. Through radioactive labeling oligonucleotides can easily be detected and monitored in biological samples. T4 polynucleotide kinase is shown to efficiently phosphorylate strands of L-nucleic acids which allows the labeling with phosphorous isotopes such as (32)P. In order to protec...

The oligonucleotide [5'-32P]pdT8d(-)dT., containing an apurinic/apyrimidinic (AP) site [d(-)], yields three radioactive products when incubated at alkaline pH: two of them, forming a doublet approximately at the level of pdT8dA when analysed by polyacrylamide-gel electrophoresis, are the result of the f-elimination reaction, whereas the third is pdT8p resulting from ,8-elimination. The incubati...

Stimulated inositolphospholipid turnover has been proposed to be initiated and sustained by hydrolysis of phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P2], which may be replenished by an enhanced flux of phosphatidylinositol (PtdIns) to PtdIns 4-phosphate (PtdIns4P) to PtdIns(4,5)P2. To determine whether there is continued hydrolysis and resynthesis of PtdIns(4,5)P2 in rat pituitary cells ...

PURPOSE Blood platelet activity increases with advancing age. This study was designed to determine if changes in a key signal-transducing mechanism in the platelet, phosphoinositide turnover, are associated with the enhanced platelet activity seen in aging. PATIENTS AND METHODS Platelets were harvested from a total of 40 healthy, non-obese, 22- to 62-year-old individuals, free of any clinical...

Platelet-activating factor stimulates phosphatidylinositol turnover in human platelets as indicated by [32P]phosphatidate accumulation in platelets pre-labelled with [32P]Pi, and by [3H]phosphatidate accumulation and [3H]phosphatidylinositol loss in platelets pre-labelled with [3H]arachidonate. These effects of platelet-activating factor are direct and are independent of the production and/or r...

Avian myeloblastosis virus produced in vitro by myeloblastic cells in suspension was labeled with 32P and 14Camino acids. After partial purification of the virus, and pronase digestion, an RNA was extracted by phenol into the aqueous phase. Glycerol gradient centrifugation showed that the 32P-labeled RNA con tained 2 distinct components: a high molecular weight fraction sedimenting at about 67 ...