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Sampaio EP, Ding L, Rose SR, Cruz P, Hsu AP, Kashyap A, Rosen LB, Smelkinson M, Tavella TA, Ferre EMN, Wierman MK, Zerbe CS, Lionakis MS, Holland SM. Novel signal transducer and activator of transcription 1 mutation disrupts small ubiquitin-related modifier conjugation causing gain of function. J Allergy Clin Immunol 2017; 141:1844-1853.e2. [PMID: 28859974 DOI: 10.1016/j.jaci.2017.07.027] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Revised: 05/31/2017] [Accepted: 07/03/2017] [Indexed: 12/14/2022]
Abstract
BACKGROUND Sumoylation is a posttranslational reversible modification of cellular proteins through the conjugation of small ubiquitin-related modifier (SUMO) and comprises an important regulator of protein function. OBJECTIVE We sought to characterize the molecular mechanism of a novel mutation at the SUMO motif on signal transducer and activator of transcription 1 (STAT1). METHODS STAT1 sequencing and functional characterization were performed in transfection experiments by using immunoblotting and immunoprecipitation in STAT1-deficient cell lines. Transcriptional response and target gene activation were also investigated in PBMCs. RESULTS We identified a novel STAT1 mutation (c.2114A>T, p.E705V) within the SUMO motif (702IKTE705) in a patient with disseminated Rhodococcus species infection, Norwegian scabies, chronic mucocutaneous candidiasis, hypothyroidism, and esophageal squamous cell carcinoma. The mutation is located in the tail segment and is predicted to disrupt STAT1 sumoylation. Immunoprecipitation experiments performed in transfected cells confirmed absent STAT1 sumoylation for E705V, whereas it was present in wild-type (WT) STAT1 cells, as well as the loss-of-function mutants L706S and Y701C. Furthermore, stimulation with IFN-γ led to enhanced STAT1 phosphorylation, enhanced transcriptional activity, and target gene expression in the E705V-transfected compared with WT-transfected cells. Computer modeling of WT and mutant STAT1 molecules showed variations in the accessibility of the phosphorylation site Y701, which corresponded to the loss-of-function and gain-of-function variants. CONCLUSION This is the first report of a mutation in the STAT1 sumoylation motif associated with clinical disease. These data reinforce sumoylation as a key posttranslational regulatory modification of STAT1 and identify a novel mechanism for gain-of-function STAT1 disease in human subjects.
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Affiliation(s)
- Elizabeth P Sampaio
- Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Bethesda, Md; Leprosy Laboratory, Oswaldo Cruz Institute, FIOCRUZ, Rio de Janeiro, Brazil.
| | - Li Ding
- Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Bethesda, Md
| | - Stacey R Rose
- Fungal Pathogenesis Unit, Laboratory of Clinical Infectious Diseases, NIAID, NIH, Bethesda, Md
| | - Phillip Cruz
- Computational Biology Section, Bioinformatics and Computational Biosciences Branch (BCBB), OCICB/OSMO/OD, NIAID, NIH, Bethesda, Md
| | - Amy P Hsu
- Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Bethesda, Md
| | - Anuj Kashyap
- Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Bethesda, Md
| | - Lindsey B Rosen
- Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Bethesda, Md
| | | | - Tatyana A Tavella
- Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Bethesda, Md
| | - Elise M N Ferre
- Fungal Pathogenesis Unit, Laboratory of Clinical Infectious Diseases, NIAID, NIH, Bethesda, Md
| | - Meredith K Wierman
- Saint Joseph Physician Network Practices, Infectious Diseases, Mishawaka, Ind
| | - Christa S Zerbe
- Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Bethesda, Md
| | - Michail S Lionakis
- Fungal Pathogenesis Unit, Laboratory of Clinical Infectious Diseases, NIAID, NIH, Bethesda, Md
| | - Steven M Holland
- Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Bethesda, Md
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