Identification of two metallothioneins in Agaricus crocodilinus reveals gene duplication and domain expansion, a pattern conserved across fungal species.

ABSTRACT: Agaricus crocodilinus (Agaricaceae), an edible saprotrophic mushroom, accumulates high concentrations of cadmium (Cd) in unpolluted environments. This study investigates whether this species has evolved mechanisms to store Cd complexed with metallothioneins (MTs), proteins that bind heavy metal ions via cysteinyl (Cys)-thiolate bonds, how these MTs originated, and how similar mechanisms are present in other fungal species. Size exclusion chromatography revealed that a substantial fraction of Cd in A. crocodilinus sporocarps was sequestered in a 3.4 kDa complex containing Cys-rich peptides. Screening a sporocarp cDNA expression library in a Cd-sensitive Saccharomyces cerevisiae strain identified two MT transcripts, AcMT1 and AcMT2, encoding 49-amino acid (AA) AcMT1 with 10 Cys and 32-AA AcM

SUBMITTER: Sacky J 

PROVIDER: S-EPMC12508003 | biostudies-literature | 2025 Oct

REPOSITORIES: biostudies-literature