Characterization of messenger RNA in protoplasts of Saccharomyces carlsbergensis

Abstract

1. (1) The pulse-labeled RNA extracted from enriched polysomal fractions of Saccharomyces carlsbergensis has been characterized by sedimentation analysis, by the effect of actinomycin D on the observed sedimentation patterns, by its sensitivity to ribonuclease action and by determinations of its base composition. It is concluded that this pulse-labeled RNA shows many of the properties which in general are ascribed to messenger RNA. 2. (2) It is shown, that polysomes which are charged with nascent α-glucosidase can be precipitated rather specifically with the aid of a purified rabbit anti-α-glucosidase γ-globulin fraction and a purified anti-rabbit γ-globulin antiserum from the goat. 3. (3) The pulse-labeled RNA extracted from the precipitated polysomes charged with nascent α-glucosidase has a sucrose gradient sedimentation pattern which is quite distinct from that of the pulse-labeled RNA from the total polysomal fraction. 4. (4) From this pattern and from the patterns obtained in pulse-double-labeling experiments with maltose-induced and non-induced protoplasts, it is tentatively concluded that the messenger RNA coding for the inducible enzyme α-glucosidase has a sedimentation coefficient of about 28 S