Abstract: Novel transgenic plants having the ability to express a functional 2-5A system, i.e., a 2-5A synthetase which produces 5'-phosphorylated, 2',5'-linked oligoadenylates (2-5A) in response to double stranded RNA (dsRNA), and a 2-5A-dependent (RNase L), are disclosed. The novel transgenic plants expressing the functional 2-5A system, such as novel transgenic tobacco plants, are immune to and resistant against viral infection. When the novel transgenic tobacco plants are exposed to three different types of plant viruses, i.e., TMV, TEV and AIMV, such viral exposure leads to necrotic local lesions in such transgenic tobacco plants instead of typical systemic infections.

Abstract: Isolated 2-5A-dependent RNases, an interferon-induced enzyme which is activated by 5'-phosphorylated, 2',5'-linked oligoadenylates (2-5A) and implicated in both the molecular mechanisms of interferon action and in the fundamental control of RNA stability in mammalian cells, and encoding sequences therefor are disclosed. The expression cloning and analysis of murine and human 2-5A-dependent RNases is also disclosed. Recombinant human 2-5A-dependent RNase produced in vitro bound an activating affinity matrix, 2-5A-cellulose, resulting in ribonuclease activity. The 2-5A binding properties of the recombinant and naturally occurring forms of 2-5A-dependent RNase are basically identical. Interferon induction of 2-5A-dependent RNase expression is demonstrated by measuring the mRNA levels in cells treated with interferon and cycloheximide.

Abstract: Isolated 2-5A-dependent RNases, an interferon-induced enzyme which is activated by 5'-phosphorylated, 2',5'-linked oligoadenylates (2-5A) and implicated in both the molecular mechanisms of interferon action and in the fundamental control of RNA stability in mammalian cells, and encoding sequences therefor are disclosed. The expression cloning and analysis of murine and human 2-5A-dependent RNases is also disclosed. Recombinant human 2-5A-dependent RNase produced in vitro bound an activating affinity matrix, 2-5A-cellulose, resulting in ribonuclease activity. The 2-5A binding properties of the recombinant and naturally occurring forms of 2-5A-dependent RNase are basically identical. Interferon induction of 2-5A-dependent RNase expression is demonstrated by measuring the mRNA levels in cells treated with interferon and cycloheximide.