2′‐Adenylated derivatives of Ap3A activate RNase L

FEBS Letters

Justesen, Just¹  Turpaev, Kyril¹  Hartmann, Rune¹ 

[1] Department of Molecular and Structural Biology, Aarhus University, Mollers Alle 130, Aarhus 8000, Denmark

关键词: RNase L;    2-5A synthetase;    Ap3A;    (2′-5′)oligoadenylate;    Interferon;    Oligoadenylate synthesis;    Poly(I)·poly(C);    AC50;    half-maximal activating concentration;    Ap3A;    diadenosine triphosphate;    2-5A;    (2′-5′)oligoadenylate;    BAP;    bovine alkaline phosphatase;    FPLC;    fast protein liquid chromatography;    IFN;    interferon;    TCA;    trichloroacetic acid;    WRS;    tryptophanyl-tRNA synthetase;   

DOI  :  10.1016/S0014-5793(99)00996-5

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The exact physiological function of Ap₃A (A5′ppp5″A, 5′5″ diadenosine triphosphate) remains unclear. Previously we have demonstrated that the human p46 2-5A synthetase (OAS1) efficiently utilises Ap₃A as an acceptor substrate for oligoadenylate synthesis. Here we show that Ap₃A(2′p5′A) _n oligonucleotides can activate the 2-5A-dependent RNase (RNase L), when the number of 2′,5′-linked adenyl residues is two or more. Under the experimental conditions applied the half-maximal activation (AC₅₀) of RNase L for 2′-adenylated Ap₃A derivatives was determined to be in nanomolar range while the AC₅₀ for 2-5A₃ was 0.4 nM. The Ap₃A(2′p5′A) _n oligonucleotides are thus less effective in activating RNase L than 2-5A. We also investigated the occurrence of 2′-adenylated Ap₃A in interferon and poly(I)·poly(C)-treated HeLa cells. In purified trichloroacetic acid-soluble extracts about 40% of RNase L-activating material is resistant to phosphatase treatment, whereas the removal of 5′-terminal phosphates greatly reduces the activating properties of 2-5A. We assume that this activity at least partly may be associated with the presence of 2′-adenylated Ap _n A derivatives with blocked 5′-terminal phosphates.

【 授权许可】

Unknown