Oligo isoadenylate

The following are recent reviews on the molecular and physical properties of this ligase (or, 2, 5 -oligo(A) polymerase or oligo-isoadenylate synthetase E). 

Table 2. Requirement of P for oligo-isoadenylate inhibition of protein synthesis...

Figure 3 Separation of various translation regulatory activities on DEAE cellulose. Cell sap from interferon-treated cultures was fractionated and assayed on mengo RNA translation (as in Table 2) in S10 from control (c) and interferon-treated cells (int) with O.O4 M g/ml dsENA. Activity without fraction = 1. Oligo-isoadenylate synthetase E (IO), factor F (18). Protein phosphatase (P) and protein kinase activator A, are discussed in the text.

II. OLIGO-ISOADENYLATE SYNTHESIS AND ACTIVATION OP NUCLEASE P A. Oligo-isoadenylate-Synthetase E... 

Oligo-isoadenylate activated nuclease activity of factor F. T I globin mRNA (0.5 M g) incubated (18) 50 min, 300C with 0.5 ixg F (PC-purified) and 0.16 pmoles, iso-A trimers (X) was analyzed by polyacrylamide gel electrophoresis, 7 iirea. Scanning of autoradiography is shown. Arrow shows direction of migration. 

C. Oligo-isoadenylate Dependent Nuclease Activity of Factor F... 

The nuclease which degrades oligo-isoadenylate copurified with the iso-A activated ribonuclease P over several steps, but was separated on hydroxylapatite. The iso-A degrading enzyme (nuclease D of Figure 1) splits (2 -5 ) P-A- to yield 5 -AMP, and more slowly (3 -5 )-A-pA. It clearly differs from known ribonucleases that are inhibited by 2 -5 dinucleotides (22). 

Studies of the relation between endonuclease F and exonuclease D should throw light on the function of oligo-isoadenylate in interferon-treated cells. 

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