Estimation of the half-life of a secretory protein message.

Synthesis of a specific secretory protein was followed in the presence of actinomycin D and cordycepin (3'-deoxyadenosine). The apparent half-life of the messenger RNA for this protein is significantly longer in the presence of actinomycin D than in the presence of cordycepin. These results suggest that actinomycin D studies of half-life in specialized cells may be inaccurate.