Intracellular distribution, sedimentation values and template activity of polyadenylic acid-containing RNA stored in Artemia salina cysts

Abstract

The post-mitochondrial supernatant of Artemia salina cysts has been fractionated by high speed centrifugation into three components: supernatant, membrane and free ribosomes. Messenger RNA is stored in these fractions as poly(A)-containing particles with sedimentation values ranging from 80 S to 4 S. Poly(A)-containing RNA derived from subcellular fractions has been submitted to sucrose density centrifugation and identified by its capacity to hybridize with 3H-poly(U) and to stimulate protein synthesis in a wheat germ lysate. Poly(A)-containing RNA from membrane and free ribosomes shows a heterogeneous distribution with S values ranging from 28 S to 4 S. Poly(A)-containing RNA from supernatant is found only in the lighter region of the gradient (18-4 S). RNA fractions of different S values can be efficiently translated in a wheat germ lysate with the formation of a characteristic pattern of proteins (8000 to 40,000 mol. wt.).