Induced synthesis, posttranslational

During the period of aging, posttranslational modified proteins and advanced glycosylation end products, which accumulate in tissues, might chronically stimulate HSP production, and affect the basal synthesis of this cell defense mechanism. In this regard, acutely induced HSP synthesis does decrease with aging. However, since the effect of age on the basal expression of HSP70 had not previously been addressed, Maiello and associates (M3) studied the age-dependent basal... 

Diphtheria toxin inactivates elongation factor 2, an enzyme required for protein synthesis (Pappenheimer, 1977) through catalyzing its ADP-ribosylation, thereby inhibiting protein synthesis and inducing cell death. Elongation factor 2 contains a unique amino acid, diph-thamide, which is formed by posttranslational modification of a histidine residue (Van Ness et ai, 1980). The ADP-ribose binds covalently to this unusual amino acid. 

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