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Ribonucleic acid synthesis and transport in animal cells at 27 degrees C.

ABSTRACT: The failure to induce glutamine synthetase in retinal cells with hydrocortisone at 27 degrees C (37 degrees C is the normal temperature for induction) led to a study of some aspects of RNA synthesis at 27 degrees C by using the method of selective labelling with radioactive precursors, sucrose-density-gradient centrifugation and radioautography. The low-temperature treatment not only decreases the rate of RNA synthesis but also interferes with the general pattern of RNA maturation and distribution. It has been found that nuclear-cytoplasmic exchange is severely altered at low temperature and may be an explanation of the failure to induce the enzyme. When the temperature is raised from 27 degrees C to 37 degrees C, the incorporation of exogenous radioactive uridine into the RNA is distorted by a pool-dilution effect that results in an ;over-shoot' phenomenon. The kinetics of labelled uridine equilibration into the UMP pool accounts for the difficulty encountered by many investigators in ;chase' efforts with unlabelled nucleosides.

SUBMITTER: Horisberger M

PROVIDER: S-EPMC1178868 | biostudies-other | 1970 Apr

REPOSITORIES: biostudies-other

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