Logo image
Structural modeling of a novel CAPN5 mutation that causes uveitis and neovascular retinal detachment
Journal article   Open access   Peer reviewed

Structural modeling of a novel CAPN5 mutation that causes uveitis and neovascular retinal detachment

Alexander G Bassuk, Steven Yeh, Shu Wu, Daniel F Martin, Stephen H Tsang, Lokesh Gakhar and Vinit B Mahajan
PloS one, Vol.10(4), pp.e0122352-e0122352
2015
DOI: 10.1371/journal.pone.0122352
PMCID: PMC4391918
PMID: 25856303
url
https://doi.org/10.1371/journal.pone.0122352View
Published (Version of record) Open Access

Abstract

CAPN5 mutations have been linked to autosomal dominant neovascular inflammatory vitreoretinopathy (ADNIV), a blinding autoimmune eye disease. Here, we link a new CAPN5 mutation to ADNIV and model the three-dimensional structure of the resulting mutant protein. In our study, a kindred with inflammatory vitreoretinopathy was evaluated by clinical eye examinations, DNA sequencing, and protein structural modeling to investigate the disease-causing mutation. Two daughters of an affected mother demonstrated symptoms of stage III ADNIV, with posterior uveitis, cystoid macular edema, intraocular fibrosis, retinal neovascularization, retinal degeneration, and cataract. The women also harbored a novel guanine to thymine (c.750G>T, p.Lys250Asn) missense mutation in exon 6 of CAPN5, a gene that encodes a calcium-activated cysteine protease, calpain-5. Modeling based on the structures of all known calpains revealed the mutation falls within a calcium-sensitive flexible gating loop that controls access to the catalytic groove. Three-dimensional modeling placed the new mutation in a region adjacent to two previously identified disease-causing mutations, all three of which likely disrupt hydrogen bonding within the gating loop, yielding a CAPN5 with altered enzymatic activity. This is the third case of a CAPN5 mutation leading to inherited uveitis and neovascular vitreoretinopathy, suggesting patients with ADNIV features should be tested for CAPN5 mutations. Structural modeling of novel variants can be used to support mechanistic consequences of the disease-causing variants.
Tomography, Optical Coherence Humans Computational Biology Models, Molecular Molecular Sequence Data DNA Primers - genetics Calpain - genetics Retinal Detachment - genetics Sequence Analysis, DNA Mutation, Missense - genetics Vitreoretinopathy, Proliferative - genetics Phenotype Pedigree Base Sequence Female Protein Conformation Uveitis - genetics Fluorescein Angiography

Details

Logo image