Messenger RNA decay and protection

The decay of messenger RNA in Bacillus subtilis has been studied under a variety of conditions which interfere with protein synthesis. Changes in the growth rate produced by altering the medium do not affect the proportion of messenger relative to total RNA. The decay rate has a large temperature coefficient varying roughly as the rate of protein synthesis. However, the decay does not depend on protein synthesis since it occurs normally in the presence of puromycin. Energy starvation produced by anaerobiosis, cyanide or azide markedly protects the messenger from its normal decay as does chloramphenicol. Puromycin will release this protection and restore rapid decay. It is suggested that the messenger is protected by virtue of being held on to a ribosome and the release of the protection occurs when the messenger is released from the ribosome.