6z2g

From Proteopedia

Crystal structure of human NLRP9 PYD

Structural highlights

6z2g is a 1 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	X-ray diffraction, Resolution 1.95Å
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

NLRP9_HUMAN As the sensor component of the NLRP9 inflammasome, plays a crucial role in innate immunity and inflammation. In response to pathogens, including rotavirus, initiates the formation of the inflammasome polymeric complex, made of NLRP9, PYCARD and CASP1. Recruitment of proCASP1 to the inflammasome promotes its activation and CASP1-catalyzed IL1B and IL18 maturation and release in the extracellular milieu. The active cytokines stimulate inflammatory responses. Inflammasomes can also induce pyroptosis, an inflammatory form of programmed cell death. NLRP9 inflammasome activation may be initiated by DHX9 interaction with viral double-stranded RNA (dsRNA), preferentially to short dsRNA segments.^[1]

Publication Abstract from PubMed

Inflammasomes are cytosolic multimeric signaling complexes of the innate immune system that induce activation of caspases. The NOD-like receptor NLRP9 recruits the adaptor protein ASC to form an ASC-dependent inflammasome to limit rotaviral replication in intestinal epithelial cells, but only little is known about the molecular mechanisms regulating and driving its assembly. Here, we present the crystal structure of the human NLRP9 pyrin domain (PYD). We show that NLRP9(PYD) is not able to self-polymerize nor to nucleate ASC specks in HEK293T cells. A comparison with filament-forming PYDs revealed that NLRP9(PYD) adopts a conformation compatible with filament formation, but several charge inversions of interfacing residues might cause repulsive effects that prohibit self-oligomerization. These results propose that inflammasome assembly of NLRP9 might differ largely from what we know of other inflammasomes.

Crystal structure of the human NLRP9 pyrin domain suggests a distinct mode of inflammasome assembly.,Marleaux M, Anand K, Latz E, Geyer M FEBS Lett. 2020 Jun 16. doi: 10.1002/1873-3468.13865. PMID:32542665^[2]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Zhu S, Ding S, Wang P, Wei Z, Pan W, Palm NW, Yang Y, Yu H, Li HB, Wang G, Lei X, de Zoete MR, Zhao J, Zheng Y, Chen H, Zhao Y, Jurado KA, Feng N, Shan L, Kluger Y, Lu J, Abraham C, Fikrig E, Greenberg HB, Flavell RA. Nlrp9b inflammasome restricts rotavirus infection in intestinal epithelial cells. Nature. 2017 Jun 29;546(7660):667-670. doi: 10.1038/nature22967. Epub 2017 Jun, 21. PMID:28636595 doi:http://dx.doi.org/10.1038/nature22967
↑ Marleaux M, Anand K, Latz E, Geyer M. Crystal structure of the human NLRP9 pyrin domain suggests a distinct mode of inflammasome assembly. FEBS Lett. 2020 Jun 16. doi: 10.1002/1873-3468.13865. PMID:32542665 doi:http://dx.doi.org/10.1002/1873-3468.13865