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Characterization of rapidly labeled ribonucleic acid of animal cells in culture

1965; Elsevier BV; Volume: 103; Issue: 3 Linguagem: Inglês

10.1016/0005-2787(65)90132-2

1879-3002

Masako Yoshikawa-Fukada, Tetsuo Fukada, Yoshimi Kawade,

DNA and Nucleic Acid Chemistry

The rapidly labeled RNA of growing FL cells in culture was shown to consist of two classes of molecules, q1 and q2, with sedimentation constants of about 40 S and 50 S, respectively. The time course of 32P-labeling and the chase experiment indicated that q2 is metabolically much more active than q1. The base composition of q1 was similar to ribosomal RNA, while that of q2 closely resembled DNA. As a working hypothesis, q1 may be assumed to be the precursor of ribosomal RNA and q2 the messenger RNA. When the total RNA was fractionated on a methylated albumin column, and the fractions comprising ribosomal RNA were examined by analytical ultracentrifugation using ultraviolet optics, a species of RNA with a sedimentation constant of 42 S was found in addition to the ribosomal RNA. This component could be greatly concentrated relative to other RNA's by chromatographic and centrifugal fractionations, and was identified as one of the rapidly labeled RNA's, q1.