Protein Structural Analysis of BP180 Mutant Isoforms Linked to Non-Herlitz Junctional Epidermolysis Bullosa

Abstract

Two chromatographic profiles, as seen in Figure S2, were used to determine the average Stoke's radius for each protein.

Molecular Identification of Collagen 17a1 as a Major Genetic Modifier of Laminin Gamma 2 Mutation-Induced Junctional Epidermolysis Bullosa in Mice

“…Direct JEB-causing alterations in the NC4 domain have also been described. The recessively acting missense mutation, R1303Q [13], [41], [42] and the 4003delTC/4080insGG mutation (which substitutes 25 erroneous AA into the NC4-COL3 domains) cause forms of JEB presumably by conformational alterations of the NC4 domain [43], [44] (Figure 7B). A disease-relevant genetic linkage between COL17A1 and LAMB3 has also been reported where the proband was a compound heterozygote for L855X and R1226X COL17A1 nonsense mutations and heterozygous for the R635X recessive LAMB3 nonsense mutation [45].…”

Junctional epidermolysis bullosa of late onset explained by mutations in COL17A1

“…Col17 consists of a globular head domain localized in the intracellular region of the hemidesmosome, an ectodomain containing a linear rod domain penetrating the plasma membrane and crossing the lamina lucida, and a flexible tail domain localized in the lamina densa 20 . The p.R1303Q mutation is predicted to affect protein folding and ligand binding, and structural analysis has demonstrated increased trypsin sensitivity probably due to alteration of the NC4 protein structure 13,21 . The mutation is localized in the flexible tail domain, which has a loop that keeps a firm hold on the lamina densa and most probably interacts with LM‐332 13,22 .…”

“…20 The p.R1303Q mutation is predicted to affect protein folding and ligand binding, and structural analysis has demonstrated increased trypsin sensitivity probably due to alteration of the NC4 protein structure. 13,21 The mutation is localized in the flexible tail domain, which has a loop that keeps a firm hold on the lamina densa and most probably interacts with LM-332. 13,22 This could well explain the low lamina lucida split in the lesional skin of our patients, witnessed by IF staining of LM-332 in both blister floor and roof.…”

The NC16A domain of collagen XVII plays a role in triple helix assembly and stability

“…The DNA vector pCEP4-sec180, which is based on the pCEP4 episomal expression vector (Invitrogen, Carlsbad, CA) and which encodes a secreted form of the collagen XVII ectodomain, was described previously [4,9]. pCEP4-sec180 was used as the template for PCR amplification of the segments of collagen XVII represented in Figure 1.…”

“…Three rabbit antisera reacting with distinct epitopes on the extracellular region of collagen XVII were used in this study. Rabbit sera R594 and R136 react with sites in NC16A and near the C-terminus of collagen XVII, as previously described [9]. Rabbit antiserum, R5151, a generous gift from Dr. Kim Yancey, recognizes sites within the C-terminal two-thirds of the collagen XVII ectodomain.…”