Inhibition of initiation of translation in L1210 cells by 8-azaguanine.

The inhibition of protein synthesis by 8-azaguanine (azaG) in L1210 cells in culture was investigated. AzaG selectively inhibited protein synthesis at concentrations where viability was decreased significantly. AzaG altered the polyribosome sedimentation profile, increasing the numbers of monosomes and smaller polysomes and decreasing the number of larger polysomes. The reversal by cycloheximide of the alterations in the polysome profile suggested that azaG inhibited the initiation of translation. This was confirmed by the demonstration of inhibition of the formation of the 43S and 80S initiation complexes.