Hereditary angioedema is an autosomal dominant disorder caused by defects in C1-esterase inhibitor (C1-INH), resulting in poorly controlled activation of the kallikrein-kinin system and bradykinin overproduction. C1-INH is a heavily glycosylated protein in the serine protease inhibitor (SERPIN) family, yet the role of these glycosylation sites remains unclear. To elucidate the functional impact of N-glycosylation in the SERPIN domain of C1-INH, we engineered four sets consisting of 26 variants at or near the N-linked sequon (NXS/T). Among these, six are reported in HAE patients and five are known C1-INH variants without accessible clinical histories. We systematically evaluated their expression, structure and functional activity with C1¯s, FXIIa and kallikrein. Our findings showed that of the eleven reported variants, seven are deleterious. Deleting N at the three naturally occurring N-linked sequons (N238, N253 and N352) results in pathologic consequences. Altering these sites by substituting N to A disrupts N-linked sugar attachment but preserves protein expression or function. Further, an additional N-linked sugar generated at N272 impairs C1-INH function. These findings highlight the importance of N-linked sequons in modulating the expression and function of C1-INH. Insights gained from identifying the pathological consequences of N-glycan variants should assist in defining more tailored therapy.
Zhen Ren, John Bao, Shuangxia Zhao, Nicola Pozzi, H. Wedner, John P. Atkinson
Usage data is cumulative from January 2025 through February 2025.
Usage | JCI | PMC |
---|---|---|
Text version | 312 | 0 |
309 | 0 | |
Supplemental data | 256 | 0 |
Citation downloads | 19 | 0 |
Totals | 896 | 0 |
Total Views | 896 |
Usage information is collected from two different sources: this site (JCI) and Pubmed Central (PMC). JCI information (compiled daily) shows human readership based on methods we employ to screen out robotic usage. PMC information (aggregated monthly) is also similarly screened of robotic usage.
Various methods are used to distinguish robotic usage. For example, Google automatically scans articles to add to its search index and identifies itself as robotic; other services might not clearly identify themselves as robotic, or they are new or unknown as robotic. Because this activity can be misinterpreted as human readership, data may be re-processed periodically to reflect an improved understanding of robotic activity. Because of these factors, readers should consider usage information illustrative but subject to change.