Origin of class B J-domain proteins involved in amyloid transactions.

ABSTRACT: J-domain protein (JDP) chaperones function widely in proteostasis. Notably, eukaryotic class B JDPs of the cytosol/nucleus prevent assembly or drive disassembly of amyloid aggregates known to cause neurodegenerative diseases, yet their evolutionary origin is not known. Members of the most ubiquitous class B subgroup, canonical B (B^C) JDPs, lack the signature zinc finger domain (ZnF) of the more prevalent class A JDPs, while having other key features in common. Our phylogenetic analysis revealed that B^C JDPs evolved more than once from class A duplicates, losing their ZnF. The cytonuclear B^Cs emerged at the base of eukaryotes. Cytonuclear class B' (i.e., B'^(ST)) JDPs that have a substrate binding domain of unknown origin, distinct from that of As

SUBMITTER: Domanski P 

PROVIDER: S-EPMC12799103 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature