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Clarification of glycosylphosphatidylinositol anchorage of OTOANCORIN and human OTOA variants associated with deafness
Author(s) -
Kim Bong Jik,
Kim DongKyu,
Han Jin Hee,
Oh Jayoung,
Kim Ah Reum,
Lee Chung,
Kim Nayoung KD,
Park HyeRim,
Kim Min Young,
Lee Sejoon,
Lee Seungmin,
Oh Doo Yi,
Park WoongYang,
Park Sungjin,
Choi Byung Yoon
Publication year - 2019
Publication title -
human mutation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.981
H-Index - 162
eISSN - 1098-1004
pISSN - 1059-7794
DOI - 10.1002/humu.23719
Subject(s) - biology , minigene , mutant , hek 293 cells , rna splicing , microbiology and biotechnology , phospholipase c , gene , mutation , alternative splicing , genetics , signal transduction , messenger rna , rna
Otoancorin (OTOA), encoded by OTOA, is required for the development of the tectorial membrane in the inner ear. Mutations in this gene cause nonsyndromic hearing loss (DFNB22). The molecular mechanisms underlying most DFNB22 remain poorly understood. Disruption of glycosylphosphatidylinositol (GPI) anchorage has been assumed to be the pathophysiology mandating experimental validation. From a Korean deaf family, we identified two trans OTOA variants (c.1320 + 5 G>C and p.Gln589ArgfsX55 [NM_144672.3]) . The pathogenic potential of c.1320 + 5 G>C was confirmed by a minigene splicing assay. To experimentally determine the GPI anchorage, wild‐type (WT) and mutant OTOA harboring p.Gln589ArgfsX55 were expressed in HEK293T cells. The mutant OTOA with p.Gln589ArgfsX55 resulted in an uncontrolled release of OTOA into the medium in contrast with phosphatidylinositol‐specific phospholipase C‐induced controlled release of WT OTOA from the cell surface. Together, the results of this reverse translational study confirmed GPI‐anchorage of OTOA and showed that downstream sequences from the 589th amino acid are critical for GPI‐anchorage.