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Human PON2 S311C polymorphism impairs airway epithelia 3OC12‐HSL inactivation and alters PON2 glycosylation
Author(s) -
Stoltz David Anthony,
Ozer Egon,
Recker Thomas,
Estin Mira,
Yang Xia,
Gansemer Nicholas,
Lusis Aldons,
Shih Diana,
Zabner Joseph
Publication year - 2009
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.23.1_supplement.lb271
Subject(s) - glycosylation , biology , n linked glycosylation , biochemistry , microbiology and biotechnology , western blot , pngase f , chemistry , glycoprotein , gene , glycan
Airway epithelial cells can degrade the P. aeruginosa quorum sensing molecule 3OC12‐HSL and inactivation of 3OC12‐HSL is mediated by an enzyme termed paraoxonase (PON). Polymorphisms have been described for PONs including a serine (S) to cysteine (C) amino acid substitution at position 311 in PON2. Human airway epithelia (HAE) homozygous for C/C at 311 have an impaired ability to inactivate 3OC12‐HSL compared to HAE homozygous for S/S. Western blot analysis for PON2 showed similar levels of PON2 protein between PON2 311C and 311S. However, while PON2 311C lysates had only one protein band at approximately 39 kDa, PON2 311S cell lysates demonstrated an additional lower molecular weight band with higher electrophoretic mobility. After N ‐linked deglycosylation with PNGase F there was no difference between the appearance of the PON2 band between 311C and S. Site‐directed mutageneis of the 4 putative N ‐linked glycosylation sites in PON2 showed that PON2 311C and the larger immunoreactive band in PON2 311S undergo N ‐linked glycosylation at Asn residues 254 and 323, while the lower immunoreactive band in PON2 311S is only glycosylated at Asn 254. We also found that glycosylation at Asn residue 323 is required for PON2 lactonase function. In summary, we found that airway epithelia homozygous for PON2 311C have an impaired ability to inactivate 3OC12‐HSL and that an altered glycosylation pattern is observed compared to PON2 311S.