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Immune dysregulation in SHARPIN-deficient mice is dependent on CYLD-mediated cell death.

ABSTRACT: SHARPIN, together with RNF31/HOIP and RBCK1/HOIL1, form the linear ubiquitin chain assembly complex (LUBAC) E3 ligase that catalyzes M1-linked polyubiquitination. Mutations in RNF31/HOIP and RBCK/HOIL1 in humans and Sharpin in mice lead to autoinflammation and immunodeficiency, but the mechanism underlying the immune dysregulation remains unclear. We now show that the phenotype of the Sharpin^cpdm/cpdm mice is dependent on CYLD, a deubiquitinase previously shown to mediate removal of K63-linked polyubiquitin chains. Dermatitis, disrupted splenic architecture, and loss of Peyer's patches in the Sharpin^cpdm/cpdm mice were fully reversed in Sharpin^cpdm/cpdm Cyld^-/- mice. We observed enhanced association of RIPK1 with the death-signaling Complex II following TNF stimulation in Sharpin^cpdm/cpdm cells, a finding dependent on CYLD since we observed reversal in Sharpin^cpdm/cpdm Cyld^-/- cells. Enhanced RIPK1 recruitment to Complex II in Sharpin^cpdm/cpdm cells correlated with impaired phosphorylation of CYLD at serine 418, a modification reported to inhibit its enzymatic activity. The dermatitis in the Sharpin^cpdm/cpdm mice was also ameliorated by the conditional deletion of Cyld using LysM-cre or Cx3cr1-cre indicating that CYLD-dependent death of myeloid cells is inflammatory. Our studies reveal that under physiological conditions, TNF- and RIPK1-dependent cell death is suppressed by the linear ubiquitin-dependent inhibition of CYLD. The Sharpin^cpdm/cpdm phenotype illustrates the pathological consequences when CYLD inhibition fails.

SUBMITTER: Ang RL

PROVIDER: S-EPMC8685717 | biostudies-literature | 2021 Dec

REPOSITORIES: biostudies-literature

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Immune dysregulation in SHARPIN-deficient mice is dependent on CYLD-mediated cell death.

Ang Rosalind L RL Chan Mark M Legarda Diana D Sundberg John P JP Sun Shao-Cong SC Gillespie Virginia L VL Chun Nicholas N Heeger Peter S PS Xiong Huabao H Lira Sergio A SA Ting Adrian T AT

Proceedings of the National Academy of Sciences of the United States of America 20211201 50

SHARPIN, together with RNF31/HOIP and RBCK1/HOIL1, form the linear ubiquitin chain assembly complex (LUBAC) E3 ligase that catalyzes M1-linked polyubiquitination. Mutations in RNF31/HOIP and RBCK/HOIL1 in humans and Sharpin in mice lead to autoinflammation and immunodeficiency, but the mechanism underlying the immune dysregulation remains unclear. We now show that the phenotype of the Sharpincpdm/cpdm mice is dependent on CYLD, a deubiquitinase previously s ...[more]

PMID: 34887354

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Immune dysregulation in SHARPIN-deficient mice is dependent on CYLD-mediated cell death.

Publications

Immune dysregulation in SHARPIN-deficient mice is dependent on CYLD-mediated cell death.

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