Biology subjects

Maciaszczyk-Dziubinska, E.

Publications and source records attributed to Maciaszczyk-Dziubinska, E..

3 recordsLinked to original sources

bioRxiv2025

Comparative functional profiling of plant ACR3 orthologs reveals metalloid-sensitive trafficking and arsenic efflux capabilities

Arsenic contamination poses a major environmental and public health challenge. In liverworts and ferns, ACR3 transporters mediate arsenite efflux and contribute to arsenic tolerance. We recently showed that ACR3 from Marchantia polymorpha (MpACR3) contains an extended N-terminal region that couples arsenic sensing to membrane trafficking. However, the function and regulation of ACR3 transporters across photosynthetic lineages remain unclear. Here, we characterize ACR3 transporters from phylogenetically distant algae and land plants using heterologous expression in yeast. All examined ACR3 proteins function as arsenic efflux transporters but display two distinct trafficking modes: constitutive plasma membrane localization or metalloid-driven relocalization from the endomembrane system. Like the previously characterized MpACR3, we show that this inducible trafficking is governed by an extended N-terminal domain unique to plant ACR3 proteins, integrating a conserved di-arginine ER/Golgi retention signal with cysteine-based arsenic sensing. These findings establish a direct mechanistic link between metalloid perception and subcellular targeting. Functional assays in Arabidopsis thaliana demonstrated that Physcomitrium patens ACR3 confers arsenic tolerance, reduces root arsenic accumulation, and retains metalloid-dependent trafficking, supporting its physiological relevance. Together, our findings uncover a conserved mechanism linking arsenic sensing to ACR3 trafficking and provide new insight into the evolution of arsenic tolerance in plants. Summary statementPlant ACR3 transporters mediate arsenic efflux and exhibit distinct trafficking modes. An N-terminal domain links arsenic sensing to the endomembrane system-plasma membrane relocalization, revealing a conserved mechanism controlling ACR3 function and arsenic tolerance across plant lineages.

plant biology↗

bioRxiv2025

Arsenic-sensing domain controls ACR3 transporter trafficking and function in Marchantia polymorpha

Arsenic, a toxic and carcinogenic metalloid, is a pervasive environmental contaminant that threatens human health through contaminated water and food. The efflux of As(III) via ACR3 transporters is an ancient detoxification mechanism conserved across prokaryotes, fungi, and plants, with the notable exception of angiosperms. Despite their evolutionary significance, plant ACR3s remain largely uncharacterized. Here, we demonstrate that MpACR3, the ACR3 orthologue from the liverwort Marchantia polymorpha, functions as a metalloid/proton antiporter, conferring resistance to arsenicals and moderate tolerance to antimony. Additionally, we uncover an arsenic-sensing domain within MpACR3 that regulates its intracellular trafficking. Under normal conditions, MpACR3 sorting to the plasma membrane is delayed, resulting in its retention within Golgi bodies. However, As(III) binding to three cysteine residues in the N-terminal cytosolic domain induces a conformational change that facilitates MpACR3 trafficking to the plasma membrane. Furthermore, mutational analysis of a conserved arginine-based motif reveals that the N-terminal domain not only controls MpACR3 accumulation at the plasma membrane but also modulates its transport activity. Importantly, this arsenic-sensing domain is conserved among plant ACR3 transporters, suggesting a plant-specific adaptation to arsenic toxicity.

plant biology↗

bioRxiv2019

The ancillary N-terminal region of the yeast AP-1 transcription factor Yap8 contributes to its DNA binding specificity

Activator protein 1 (AP-1) is one of the largest families of basic leucine zipper (bZIP) transcription factors in eukaryotic cells. How AP-1 proteins achieve target DNA binding specificity remains elusive. In Saccharomyces cerevisiae, the AP-1-like protein (Yap) family comprises eight members (Yap1 to Yap8) that display distinct genomic target sites despite high sequence homology of their DNA binding bZIP domains. In contrast to the other members of the Yap family, which preferentially bind to short (7-8 bp) DNA motifs, Yap8 binds to an unusually long DNA motif (13 bp). It has been unclear what determines this unique specificity of Yap8. In this work, we use molecular and biochemical analysis combined with computer-based structural design and molecular dynamics simulations of Yap8-DNA interactions to better understand the structural basis of DNA binding specificity determinants. We identify specific residues in the N-terminal tail preceding the basic region, which define stable association of Yap8 with the ACR3 promoter. We propose that the N-terminal tail directly interacts with DNA and stabilizes Yap8 binding to the 13 bp motif. Thus, beside the core basic region, the adjacent N-terminal region contributes to alternative DNA binding selectivity within the AP-1 family.

genetics↗