𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Inhibitors of RNA synthesis and passage of chick embryo fibroblasts through the G1 period

✍ Scribed by David E. Chadwick; George G. Ignotz; Ronald A. Ignotz; Irving Lieberman

Publisher
John Wiley and Sons
Year
1980
Tongue
English
Weight
847 KB
Volume
104
Category
Article
ISSN
0021-9541

No coin nor oath required. For personal study only.

✦ Synopsis

Abstract

Events that are essential for progression through the G1 period begin immediately or shortly after resting chick embryo cells are given fresh medium with serum. The following observations support the contention that the critical events include the production of non‐ribosomal RNAs: (1) Addition to the “shift‐up” medium of either of two inhibitors of RNA formation, comptothecin or 5, 6‐dichloro−1‐β‐D‐ribofuranosylbenzimidazole, delays the onset of DNA replication by about the length of time the cells are exposed to the drugs. (2) Although entry into the S phase is delayed by the inhibitors, the slopes of the DNA response curves are identical to that of control cultures. (3) Neither drug reduces significantly the rate of overall protein synthesis. Observations (2) and (3) are taken to mean that expansion of the G1 period is not due to cell damage. (4) A third inhibitor of RNA synthesis, cordycepin, also delays passage of stimulated cells throgh the G1 phase, but, in this case, the length of the delay period is greater than that of the exposure period. (5) A low dose of actinomycin D does not impede movement towards the S phase, even though the synthesis of preribosomal RNA is considerably reduced.

The possibility is considered that the essential G1 molecules are mRNAs.

📜 SIMILAR VOLUMES

Regulation of the G1 → S phase transitio
Regulation of the G1 → S phase transition in chick embryo fibroblasts with α-keto acids and L-alanine
✍ John W. Groelke; Joel B. Baseman; Harold Amos 📂 Article 📅 1979 🏛 John Wiley and Sons 🌐 English ⚖ 608 KB

## Abstract Temporal inhibition of protein synthesis with cycloheximide prevents subsequent insulin, but not serum‐stimulated DNA synthesis in G~1~‐arrested chick embryo fibroblasts (CEF). The inhibition is measured by the incorporation of ^3^H‐thymidine into acid insoluble material and confirmed b

The requirement for RNA synthesis in the
The requirement for RNA synthesis in the differentiation of cultured chick embryo chondrocytes
✍ Solursh, Michael ;Meier, Stephen 📂 Article 📅 1972 🏛 John Wiley and Sons 🌐 English ⚖ 787 KB

## Abstract Secondary chick embryo sternal chondrocyte colonies, derived from differentiated clones, were treated with 0.005 μg/ml of actinomycin D for 18 hours. While RNA synthesis was inhibited by 70%, both growth and matrix accumulation were inhibited. The incorporation of ^3^H‐uridine into acid

Coordinate control of collagen synthesis
Coordinate control of collagen synthesis and cell growth in chick embryo fibroblasts and the effect of viral transformation on collagen synthesis
✍ James Kamine; Harry Rubin 📂 Article 📅 1977 🏛 John Wiley and Sons 🌐 English ⚖ 837 KB

## Abstract Using collagenase digestion as an assay for collagen in partially synchronized secondary cultures of chick embryo fibroblasts, we find that the rate of collagen synthesis remains at a constant fraction of overall protein synthesis (5%) regardless of the growth rate of the cells even whe

Decreased heme content and cessation of
Decreased heme content and cessation of cell growth in cultured chick embryo fibroblasts in the presence of horse serum: Stimulation of heme synthesis and cell growth by iron
✍ Claude Verger; José Imbenotte 📂 Article 📅 1982 🏛 John Wiley and Sons 🌐 English ⚖ 586 KB

## Abstract A new spectrofluorometric method for heme quantitation in cultured fibroblasts is described. The method includes: (1) heme extraction by methanol/sulfuric acid, (2) partial purification of heme by a microchromatographic method, and (3) treatment of the purified heme by oxalic acid follo