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Homozygous STAT2 gain-of-function mutation by loss of USP18 activity in a patient with type I interferonopathy

Type I interferonopathies are monogenic disorders characterized by enhanced type I interferon (IFN-I) cytokine activity. Inherited USP18 and ISG15 deficiencies underlie type I interferonopathies by preventing the regulation of late responses to IFN-I. Specifically, USP18, being stabilized by ISG15,...

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Detalles Bibliográficos
Autores principales: Gruber, Conor, Martin-Fernandez, Marta, Ailal, Fatima, Qiu, Xueer, Taft, Justin, Altman, Jennie, Rosain, Jérémie, Buta, Sofija, Bousfiha, Aziz, Casanova, Jean-Laurent, Bustamante, Jacinta, Bogunovic, Dusan
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Rockefeller University Press 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7201920/
https://www.ncbi.nlm.nih.gov/pubmed/32092142
http://dx.doi.org/10.1084/jem.20192319
Descripción
Sumario:Type I interferonopathies are monogenic disorders characterized by enhanced type I interferon (IFN-I) cytokine activity. Inherited USP18 and ISG15 deficiencies underlie type I interferonopathies by preventing the regulation of late responses to IFN-I. Specifically, USP18, being stabilized by ISG15, sterically hinders JAK1 from binding to the IFNAR2 subunit of the IFN-I receptor. We report an infant who died of autoinflammation due to a homozygous missense mutation (R148Q) in STAT2. The variant is a gain of function (GOF) for induction of the late, but not early, response to IFN-I. Surprisingly, the mutation does not enhance the intrinsic activity of the STAT2-containing transcriptional complex responsible for IFN-I–stimulated gene induction. Rather, the STAT2 R148Q variant is a GOF because it fails to appropriately traffic USP18 to IFNAR2, thereby preventing USP18 from negatively regulating responses to IFN-I. Homozygosity for STAT2 R148Q represents a novel molecular and clinical phenocopy of inherited USP18 deficiency, which, together with inherited ISG15 deficiency, defines a group of type I interferonopathies characterized by an impaired regulation of late cellular responses to IFN-I.