The DeltaF508 cystic fibrosis mutation impairs domain-domain interactions and arrests post-translational folding of CFTR.

TitleThe DeltaF508 cystic fibrosis mutation impairs domain-domain interactions and arrests post-translational folding of CFTR.
Publication TypeJournal Article
Year of Publication2005
AuthorsDu K, Sharma M, Lukacs GL
JournalNat Struct Mol Biol
Volume12
Issue1
Pagination17-25
Date Published2005 Jan
ISSN1545-9993
KeywordsAnimals, Binding Sites, Cell Line, Cricetinae, Cystic Fibrosis, Cystic Fibrosis Transmembrane Conductance Regulator, Humans, Peptide Hydrolases, Phenylalanine, Protein Folding, Protein Processing, Post-Translational, Sequence Deletion
Abstract

Misfolding accounts for the endoplasmic reticulum-associated degradation of mutant cystic fibrosis transmembrane conductance regulators (CFTRs), including deletion of Phe508 (DeltaF508) in the nucleotide-binding domain 1 (NBD1). To study the role of Phe508, the de novo folding and stability of NBD1, NBD2 and CFTR were compared in conjunction with mutagenesis of Phe508. DeltaF508 and amino acid replacements that prevented CFTR folding disrupted the NBD2 fold and its native interaction with NBD1. DeltaF508 caused limited alteration in NBD1 conformation. Whereas nonpolar and some aliphatic residues were permissive, charged residues and glycine compromised the post-translational folding and stability of NBD2 and CFTR. The results suggest that hydrophobic side chain interactions of Phe508 are required for vectorial folding of NBD2 and the domain-domain assembly of CFTR, representing a combined co- and post-translational folding mechanism that may be used by other multidomain membrane proteins.

DOI10.1038/nsmb882
Alternate JournalNat. Struct. Mol. Biol.
PubMed ID15619635