Degradation of RIG-I following cytomegalovirus infection is independent of apoptosis.
Many viruses have evolved strategies to either evade or hijack host cell immune programs, as a means of promoting their own reproduction. For example, the human cytomegalovirus (HCMV) immediate-early protein vMIA/UL37ex1 inhibits host cell apoptosis, and its expression during infection aids virus replication. Here it is shown that stable expression of vMIA/UL37ex1 reduces cleavage of the innate immune response-proteins MAVS and RIG-I by caspases during apoptosis. Unexpectedly, it is demonstrated that RIG-I, but not MAVS, is degraded during HCMV infection. This process occurs in a non-apoptotic manner, and provides new evidence that HCMV may have evolved a unique strategy to evade RIG-I-mediated immune responses.
Scott
Iain
I
Biochemistry Section, Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, Bethesda, MD 20892, USA. scotti@mail.nih.gov
D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism; D017209:Apoptosis; D003587:Cytomegalovirus / Q000472:pathogenicity*; D000071457:DEAD Box Protein 58; D053487:DEAD-box RNA Helicases / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D017874:Immediate-Early Proteins / Q000378:metabolism; D011971:Receptors, Immunologic
D048868:Adaptor Proteins, Signal Transducing; D017874:Immediate-Early Proteins; C505371:MAVS protein, human; D011971:Receptors, Immunologic; C420323:UL37 protein, Human herpesvirus 5; C452820:RIGI protein, human; D000071457:DEAD Box Protein 58; D053487:DEAD-box RNA Helicases