Interaction between pyrin and the apoptotic speck protein (ASC) modulates ASC-induced apoptosis.
Patients with familial Mediterranean fever suffer sporadic inflammatory attacks characterized by fever and intense pain (in joints, abdomen, or chest). Pyrin, the product of the MEFV locus, is a cytosolic protein whose function is unknown. Using pyrin as a "bait" to probe a yeast two-hybrid library made from neutrophil cDNA, we isolated apoptotic speck protein containing a caspase recruitment domain (CARD) (ASC), a proapoptotic protein that induces the formation of large cytosolic "specks" in transfected cells. We found that when HeLa cells are transfected with ASC, specks are formed. After co-transfection of cells with ASC plus wild type pyrin, an increase in speck-positive cells is found, and speck-positive cells show increased survival. Immunofluorescence studies show that pyrin co-localizes with ASC in specks. Speck localization requires exon 1 of pyrin, but exon 1 alone of pyrin does not result in an increase in the number of specks. Exon 1 of pyrin and exon 1 of ASC show 42% sequence similarity and resemble death domain-related structures in modeling studies. These findings link pyrin to apoptosis pathways and suggest that the modulation of cell survival may be a component of the pathophysiology of familial Mediterranean fever.
Richards
N
N
Department of Cell and Developmental Biology, The University of Michigan Medical School, Ann Arbor, Michigan, 48109-0616, USA.
Schaner
P
P
Diaz
A
A
Stuckey
J
J
Shelden
E
E
Wadhwa
A
A
Gumucio
D L
DL
D000199:Actins / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis; D051017:Apoptosis Regulatory Proteins; D029681:Arabidopsis Proteins; D015153:Blotting, Western; D053468:CARD Signaling Adaptor Proteins; D002460:Cell Line; D002470:Cell Survival; D003598:Cytoskeletal Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D018076:DNA, Complementary / Q000378:metabolism; D005091:Exons; D044943:Fatty Acid Desaturases / Q000737:chemistry / Q000235:genetics; D015723:Gene Library; D006367:HeLa Cells; D006801:Humans; D020287:In Situ Nick-End Labeling; D051379:Mice; D008856:Microscopy, Fluorescence; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009504:Neutrophils / Q000378:metabolism; D010957:Plasmids / Q000378:metabolism; D011233:Precipitin Tests; D011485:Protein Binding; D017510:Protein Folding; D017434:Protein Structure, Tertiary; D011506:Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D000071198:Pyrin; D017386:Sequence Homology, Amino Acid; D014162:Transfection; D014404:Tubulin / Q000378:metabolism; D020798:Two-Hybrid System Techniques; D014544:Uridine Triphosphate / Q000378:metabolism
D000199:Actins; D051017:Apoptosis Regulatory Proteins; D029681:Arabidopsis Proteins; D053468:CARD Signaling Adaptor Proteins; D003598:Cytoskeletal Proteins; D018076:DNA, Complementary; C000604192:MEFV protein, human; C000604193:Mefv protein, mouse; C402202:PYCARD protein, human; D011506:Proteins; C498534:Pycard protein, mouse; D000071198:Pyrin; D014404:Tubulin; D044943:Fatty Acid Desaturases; C084083:Fad7 protein, Arabidopsis; D014544:Uridine Triphosphate