these atp-stimulated systems seem to be responsible for the rapid degradation of abnormal proteins in vivo , but they may also be involved in the catabolism of normal cell proteins , limited proteolysis , such as the processing of precursors for secreted or membrane proteins , and the selective inactivation of specific proteins , as occurs in the atp-dependent cleavage of the lambda repressor by the reca protein .
C0007634
normal cell
C1327616
secreted