Open AccessControl of the ppp(A2′p) n A System in HeLa Cells
Author(s) -
SILVERMAN Robert H.,
CAYLEY P. Jane,
KNIGHT Matilda,
GILBERT Chiristopher S.,
KERR Ian M.
Publication year - 1982
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1982.tb05915.x
Subject(s) - interferon , hela , virus , rnase p , cleavage (geology) , biology , rna , virology , microbiology and biotechnology , nuclease , cell culture , enzyme , gene , biochemistry , genetics , paleontology , fracture (geology)
HeLa cells have an unusually high level of ppp(A2′p) n A synthetase(n = 2 to ≥4) even in the absence of interferon treatment. In accord with this ppp(A2′p) n A and ppp(A2′p) n A‐mediated ribosomal RNA cleavage occur naturally in response to encephalomyocarditis virus infection in control as well as in intcrleron‐treated cells. Despite this, in the absence of interferon treatment, encephalomyocarditis virus grows well In these cells. A possible explanation for this paradox is that the ppp(A2′p) n A dependent RNase is lost or inactivated at later times post‐infection in control but not in interferon‐treated cells. It appears, therefore, to bc the prevention by interferon of the virus‐mediated inhibition of the ppp(A2′p) n ‐dependent nuclease rather than the absolute level or induction of the ppp(A2′p) n A synthetase which is crucial for the activity of the ppp(A2′p) n A system in HeLa cells. These results provide evidence for a further level of control in the ppp(A2′p) n A system and show that limited ppp(A2′p) n A‐mediated ribosomal RNA cleavage alone is not sufficient to cause;in inhibition of virus growth.