PROTEIN-SYNTHESIS IN COLLAGEN LATTICE-CULTURED FIBROBLASTS IS CONTROLLED AT THE RIBOSOMAL LEVEL

Fibroblasts cultivated in three-dimensional lattices exhibit a large d ecrease of protein synthesis, mainly through transcriptional control. However, no previous work was devoted to a potential ribosomal regulat ion. We evaluated ribosomal ribonucleic acid (RNA) in monolayer- and c ollagen lattice-cultured fibroblasts, After one week of culture, total RNA was 60% lower in lattice-cultured fibro blasts than in monolayer- cultured cells. The decrease was identical for 18 S and 28 S rRNA subf ractions. The half-life of RNA was much shorter in collagen lattice-cu ltured fibroblasts than in monolayers, These results suggest that prot ein synthesis in lattice-cultured fibroblasts is partly regulated at t he ribosomal level.