Collagen IVα345 dysfunction in glomerular basement membrane diseases. III. A functional framework for α345 hexamer assembly
| Autor: | Juan Saus, Tatiana Mikhailova, Billy G. Hudson, Jean-Christophe Harmange, Mary C Barber, Vadim Pedchenko, Sergei P. Boudko |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
0301 basic medicine
Collagen Type IV GP Goodpasture’s disease SEC size-exclusion chromatography Anti-Glomerular Basement Membrane Disease Cell Nephritis Hereditary Random hexamer Biochemistry law.invention Cell Line Pathogenesis 03 medical and health sciences DN diabetic nephropathy law medicine Native state TBS tris-buffered saline Alport syndrome Protein Structure Quaternary Molecular Biology 030102 biochemistry & molecular biology Chemistry Glomerular basement membrane Cell Biology medicine.disease In vitro AFM atomic force microscopy 030104 developmental biology medicine.anatomical_structure Mutation Recombinant DNA Biophysics LCL loop-crevice-loop AS Alport syndrome Protein Multimerization GBM glomerular basement membrane Research Article |
| Zdroj: | The Journal of Biological Chemistry |
| ISSN: | 1083-351X 0021-9258 |
| Popis: | We identified a genetic variant, an 8-residue appendage, of the α345 hexamer of collagen IV present in patients with glomerular basement membrane (GBM) disease, Goodpasture's disease (GP) and Alport syndrome (AS) (see Companion Paper I), and determined the long-awaited crystal structure of hexamer (see Companion Paper II). We sought to elucidate how variants cause GBM disease by exploring the mechanism of hexamer assembly. Chloride ions induced in vitro hexamer assembly in a composition-specific manner in the presence of equimolar concentrations of α3, α4 and α5 NC1 monomers. Chloride ions, together with sulfilimine crosslinks, stabilized the assembled hexamer. Furthermore, the chloride ion-dependent assembly revealed conformational plasticity of the LCL bioactive sites, a critical property underlying bioactivity and pathogenesis. We explored the native mechanism by expressing recombinant α345 mini-protomers in cell culture and characterizing the expressed proteins. Our findings revealed: NC1-directed trimerization, forming protomers inside the cell, and hexamerization forming scaffolds outside the cell; and a Cl gradient signaled hexamerization. This assembly detail, along with a crystal structure, provides a framework for understanding hexamer dysfunction. Restoration of the native conformation of bioactive sites or α345 hexamer replacement are prospective approaches to therapeutic intervention. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|