Maximus Guorgui | 2025 I.S. Symposium
狈补尘别:听Maximus Guorgui
罢颈迟濒别:听Exploring How a Mutant Form of Yeast Thioredoxin Reductase Trr1 Causes Growth Arrest
惭补箩辞谤:听Biochemistry and Molecular Biology
础诲惫颈蝉辞谤:听James West
Thioredoxin reductase (Trr1) partners with thioredoxin (Trx) to protect against reactive oxygen species (ROS) and support deoxyribonucleotide biosynthesis. In yeast, Trr1 has two critical cysteines, C145 (catalytic) and C142 (resolving), which facilitate Trx reduction. Yeast lacking Trr1 exhibit growth arrest when overexpressing a C145A mutant of Trr1. This growth sensitivity is specific to strains lacking Trr1, as shown by testing different genetic backgrounds (wild-type, trr1螖, trx1螖 trx2螖, and trr1螖 trx1螖 trx2螖) using a galactose-inducible system. Non-reducing SDS-PAGE analysis revealed high molecular weight (~70 kDa) bands in trr1-deficient yeast expressing either wild-type or C145A Trr1, suggesting the formation of disulfide-linked Trr1 homodimers. These findings imply that other conserved cysteines in Trr1, such as C142 or a semi-conserved C-terminal cysteine, may form non-productive complexes with unknown proteins. This raises the possibility of Trx-independent roles for Trr1 and related reductases. Further studies aim to identify these interactions and elucidate the mechanism behind the observed growth arrest.
Posted in Symposium 2025 on May 1, 2025.
