Autocitrullination of human peptidyl arginine deiminase type 4 regulates protein citrullination during cell activation.

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Citation

Andrade F, Darrah E, Gucek M, Cole RN, Rosen A, Zhu X

Autocitrullination of human peptidyl arginine deiminase type 4 regulates protein citrullination during cell activation.

Arthritis Rheum. 2010 Jun;62(6):1630-40. doi: 10.1002/art.27439.

PubMed ID
20201080 [ View in PubMed
]
Abstract

OBJECTIVE: To address mechanisms that control the activity of human peptidyl arginine deiminase type 4 (PAD-4). METHODS: PAD-4 autocitrullination was determined by anti-modified citrulline immunoblotting, using purified recombinant and endogenous PAD-4 from activated human primary neutrophils and cell lines expressing PAD-4. The citrullination sites in PAD-4 were determined by mass spectrometry. Mechanisms of autocitrullination-induced inactivation and the functional consequences of autocitrullination in PAD-4 polymorphic variants were addressed using purified components and cell lines expressing PAD-4 wild-type, PAD-4 mutant, and PAD-4 polymorphic variants relevant to rheumatoid arthritis (RA). RESULTS: PAD-4 is autocitrullinated in vitro and during activation of primary cells and cell lines expressing PAD-4. Interestingly, this modification inactivated the function of the enzyme. The efficiency of inactivation differed among genetically defined PAD-4 variants relevant to RA. PAD-4 was citrullinated at 10 sites, which are clustered into 3 distinct regions, including a cluster of arginines around the active site cleft where Arg-372 and -374 were identified as the potential autocitrullination targets that inactivate the enzyme. Autocitrullination also modified the structure of PAD-4, abrogating its recognition by multiple rabbit antibodies, but augmenting its recognition by human anti-PAD-4 autoantibodies. CONCLUSION: Our findings suggest that autocitrullination regulates the production of citrullinated proteins during cell activation, and that this is affected by structural polymorphisms in PAD-4. Autocitrullination also influences PAD-4 structure and immune response.

DrugBank Data that Cites this Article

Polypeptides
NameUniProt ID
Protein-arginine deiminase type-4Q9UM07Details