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Detection of Inflammasome Activation and Pyroptotic Cell Death in Murine Bone Marrow-derived Macrophages
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NMR structure of the apoptosis- and inflammation-related NALP1 pyrin domain

Sebastian Hiller1, Andreas Kohl, Francesco Fiorito

  • 1Institut für Molekularbiologie und Biophysik, Eidgenössische Technische Hochschule Zürich, CH-8093, Zürich, Switzerland.

Structure (London, England : 1993)
|October 7, 2003
PubMed

Insights

Researchers determined the NMR structure of the PYRIN domain (PYD) of NALP1, revealing a unique structural feature. This finding offers insights into the innate immune response and familial Mediterranean fever.

Area of Science:

  • Structural Biology
  • Immunology
  • Molecular Biology

Background:

  • Signaling in apoptosis and inflammation involves death domain superfamily proteins, including the pyrin domain (PYD) subfamily.
  • Three-dimensional structures are known for death domain (DD), death effector domain (DED), and caspase recruitment domain (CARD) subfamilies, typically featuring six alpha helices.
  • The PYD subfamily is abundant, but its structural information has been limited.

Purpose of the Study:

  • To present the NMR structure of the PYRIN domain (PYD) of NALP1.
  • To investigate the structural basis of NALP1's role in innate immunity and inflammasome complexes.
  • To explore potential links between NALP1 PYD structure and familial Mediterranean fever (FMF).

Main Methods:

  • Nuclear Magnetic Resonance (NMR) spectroscopy was employed to determine the three-dimensional structure.
  • The study focused on the PYD of NALP1, a key protein in innate immune response.

Main Results:

  • The NMR structure of NALP1 PYD was elucidated.
  • A unique structural feature was identified: the third alpha helix is replaced by a flexibly disordered loop.
  • This structure contrasts with the common six-alpha-helix fold observed in other death domain superfamily members.

Conclusions:

  • The unique structure of NALP1 PYD, with its disordered loop, provides new insights into protein interactions within the death domain superfamily.
  • This structural characteristic may be crucial for NALP1's function in the innate immune response and inflammasome assembly.
  • The findings suggest a potential molecular basis for familial Mediterranean fever (FMF), a genetic disorder linked to NALP1 mutations.

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