INTRACELLULAR DISTRIBUTION OF BASIC PROTEINS IN CHINESE HAMSTER OVARY CELL

Basic proteins were obtained by acid extraction from whole cells and from nuclei, nucleoli, chromatin, cytoplasmic ribosomes and lysosomes of fluid cultured Chinese hamster ovary (CHO) cells. The limits of nucleoprotein dissociation ranged from pH 2.8-0.6. Basic proteins isolated from whole cells demonstrated complex electrophoretic patterns containing approximately 30 components. Basic proteins from nuclei demonstrated less complex banding patterns, while the patterns from nucleoli and chromatin qualitatively resembled those from nuclei. Lysosomal basic protein patterns resembled those of nuclei with three additional bands which were present in whole cell preparations, were observed as trace components in ribosomal preparations and were absent in nuclear basic proteins. Ribosomal basic proteins demonstrated a complex banding pattern which appeared both to share certain fractions with nuclear and lysosomal fractions and to contain a number of unique components. A comparison of relative band staining intensities among the preparations, both visually and by means of a photodensitometer, suggested for the common bands a distribution of a mixture of basic proteins among intracellular sites, the proportions of which mixture varied according to the individual locus. © 1968.