Original Articles
Studies on the Microsomes of Yeast Cells Treated with Blasticidin S
1965 Volume 18 Issue 2 Pages 77-81
Details
1965 Volume 18 Issue 2 Pages 77-81
An antibiotic, blasticidin S (BcS), found in 1958 by Takeuchi et al1). from Streptomyces griseochromogenes Fukunaga and isolated in a pure crystalline state has been widely used in Japan to protect against blast disease of paddy rice plant. Misato et al2). have found that the antibiotic completely inhibits protein synthesis in mycelia of the rice blast fungus, Pilicularia oryzae, although it shows no effect on incorporation of phosphate into nucleic acid. Recently, Huang et al3). have reported that BcS inhibits the amino acid transfer from sRNA to ribosomal protein in the cell-free system of P. oryzae. A number of papers have been published on the antibiotics that give rise to similar effects, e.g. chloramphenicol (CP)4, 5) puromycin (PRM)6) and cycloheximide7).
A previous paper8) has shown that when the growth of yeast cells is partially inhibited by the addition of BcS, a strikingly large quantity of ribonucleic acid (RNA) accumulates in the yeast cells. The RNA accumulated there was quite stable and retained in the cells even after the yeast cells were transferred to a new buffer solution. In a sedimentation experiment, most of the RNA synthesized in the presence of BcS was found to exist in the microsomal fraction9).
Dagley et al10). have found in the sedimentation analysis of bacterial cell extract that CP causes a remarkable accumulation of 14S and 18S ribonucleoprotein (RNP), the former showing a CP-specific RNP and not found in normal cells. Nomura et al11. have reported that 15S RNP found in CP-treated cells of Escherichia coli is converted either to 24S or 31S RNP when magnesium ion concentration is increased. These CP-particles were electrophoretically separated from normal ribosomes. PRM has also been known to produce RNP particles of 30S or those of less than the former in the cell extract of Pseudomonas fluorescence12).
The present paper deals with some investigations of the RNP derived from BcS-treated yeast cells, indicating that BcS also causes formation of abnormal RNP particles in the cells.
