The B30.2 domain of pyrin, the familial Mediterranean fever protein, interacts directly with caspase-1 to modulate IL-1 beta production
- Author(s)
- Chae, JJ; Wood, G; Masters, SL; Richard, K; Park, G; Smith, BJ; Kastner, DL;
- Details
- Publication Year 2006-06-27,Volume 103,Issue #26,Page 9982-9987
- Journal Title
- PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
- Publication Type
- Journal Article
- Abstract
- Familial Mediterranean fever (FMF) is a recessively inherited autoinflammatory disorder with high carrier frequencies in the Middle East. Pyrin, the protein mutated in FMF, regulates caspase-1 activation and consequently IL-1 beta production through cognate interaction of its N-terminal PYRIN motif with the ASC adaptor protein. However, the preponderance of mutations reside in pyrin's C-terminal B30.2 domain. Here we demonstrate direct interaction of this domain with caspase-1. In lysates from cells not expressing ASC, reciprocal GST pull-downs demonstrated the interaction of pyrin with the p20 and p10 catalytic subunits of caspase-1. Coimmunoprecipitations of pyrin and caspase-1 from THP-1 human monocytic cells were consistent with the interaction of endogenous proteins. The C-terminal B30.2 domain of pyrin is necessary and sufficient for the interaction, and binding was reduced by FMF-associated B30.2 mutations. Full-length pyrin attenuated IL-1 beta production in cells transfected with a caspase-1/IL-1 beta construct, an effect diminished by FMF-associated B30.2 mutations and in B30.2 deletion mutants. Modeling of the crystal structure of caspase-1 with the deduced structure of the pyrin B30.2 domain corroborated both the interaction and the importance of M694V and M680I pyrin mutations. Consistent with a net inhibitory effect of pyrin on IL-1 beta activation, small interfering RNA (siRNA)-mediated pyrin knockdown in THP-1 cells augmented IL-1 beta production in response to bacterial LPS. Moreover, the IL-1 receptor antagonist anakinra suppressed acute-phase proteins in a patient with FMF and amyloidosis. Our data support a direct, ASC-independent effect of pyrin on IL-1 beta activation and suggest heightened IL-1 responsiveness as one factor selecting for pyrin mutations.
- Publisher
- NATL ACAD SCIENCES
- Keywords
- NF-KAPPA-B; AUTOINFLAMMATORY DISEASES; INFLAMMATORY CASPASES; ACTIVATING ADAPTER; RECRUITMENT DOMAIN; CARD PROTEIN; APOPTOSIS; GENE; ASC; MEMBER
- Publisher's Version
- https://doi.org/10.1073/pnas.0602081103
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- Refer to copyright notice on published article.
Creation Date: 2006-06-27 12:00:00