A study is presented on the effects of cyclic adenosine 3':5' monophosphate (cyclic AMP) on ribosomal protein phosphorylation in rabbit reticulocytes. The phosphoryl groups in the five different ribosomal phosphoproteins turn over intracellularly and become radioactive when the cells are incubated with [32P] orthophosphate. These phosphoproteins are present in highly purified ribosomal subunits which lack messenger ribonucleic acid. Cyclic AMP and N6,O26 dibutyryl adenosine 3':5' monophosphate stimulate the incorporation of radioactivity into the ribosomal phosphoproteins. This increase in labeling occurs rapidly and is caused by two separable influences. First, cyclic AMP causes an increase in the specific activity of the incorporated phosphoryl groups. Second, cyclic AMP specifically causes increased phosphorylation of one among the ribosomal phosphoproteins. This protein has a molecular weight of approximately 27,500 and is located on the smaller ribosomal subunits.
|Original language||English (US)|
|Number of pages||4|
|Journal||Journal of Biological Chemistry|
|Publication status||Published - 1974|
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