The ribosomes of Aspergillus giganteus are sensitive to the cytotoxic action of alpha-sarcin.
Ribosomes in lysates prepared from the mycelia of Aspergillus giganteus MDH 18894, which are actively secreting alpha-sarcin, do not contain the alpha-sarcin lesion. However, the addition of exogenous alpha-sarcin to these same lysates results in cleavage of the 26 S rRNA of the 60 S ribosomal subunit, characteristic of the cytotoxic action of alpha-sarcin. We conclude that A. giganteus ribosomes are not inherently resistant to the action of alpha-sarcin but are protected in vivo by producing alpha-sarcin in an inactive form and/or by the efficient cotranslational secretion of the toxin.
Miller
S P
SP
Department of Biochemistry, University of Minnesota, Minneapolis 55455.
Bodley
J W
JW
D001230:Aspergillus / Q000187:drug effects / Q000378:metabolism*; D004722:Endoribonucleases; D005656:Fungal Proteins / Q000494:pharmacology*; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology*; D012270:Ribosomes / Q000187:drug effects / Q000378:metabolism*
D005656:Fungal Proteins; D011500:Protein Synthesis Inhibitors; C014801:alpha-sarcin; D004722:Endoribonucleases