Yeast expression of mammalian Onzin and fungal FCR1 suggests ancestral functions of PLAC8 proteins in mitochondrial metabolism and DNA repair

Abstract

The cysteine-rich PLAC8 domain of unknown function occurs in proteins found in most Eukaryotes. PLAC8-proteins play important yet diverse roles in different organisms, such as control of cell proliferation in animals and plants or heavy metal resistance in plants and fungi. Mammalian Onzin can be either pro-proliferative or pro-apoptotic, depending on the cell type, whereas fungal FCR1 confers cadmium tolerance. Despite their different role in different organisms, we hypothesized common ancestral functions linked to the PLAC8 domain. To address this hypothesis, and to investigate the molecular function of the PLAC8 domain, murine Onzin and fungal FCR1 were expressed in the PLAC8-free yeast Saccharomyces cerevisiae . The two PLAC8-proteins localized in the nucleus and induced almost identical phenotypes and transcriptional changes when exposed to cadmium stress. Like FCR1, Onzin also reduced DNA damage and increased cadmium tolerance by a DUN1-dependent pathway. Both proteins activated transcription of ancient mitochondrial pathways such as leucine and Fe-S cluster biosynthesis, known to regulate cell proliferation and DNA repair in yeast. These results strongly suggest a common ancestral function of PLAC8 proteins and open new perspectives to understand the role of the PLAC8 domain in the cellular biology of Eukaryotes.

A novel family of PLAC8 motif-containing/PCR genes mediates Cd tolerance and Cd accumulation in rice

“…In addition, our early bioinformatics prediction showed that OsPCR1 and OsPCR3 were mainly located in Cytoplasm or periplasm and contained the CC/LXXXXCPC conserved motif. We suggest that OsPCR1 and OsPCR3 may take part in inducing transcriptional changes in rice seedlings when exposed to Cd stress, then reduced DNA damage to increase Cd tolerance and influenced the Cd accumulation in rice [18]. A working model for OsPCR was suggested in Fig.…”

“…The plant cadmium resistance protein (PCR) which belonged to a membrane protein family should contain CCXXXXCPC or CL/FXXXXCPC conserved amino acid sequences to be effective, and a PLAC8 domain was reported as associate with cadmium resistance in plants [15][16][17][18]. Many functions have been reported for PLAC8 domain-containing proteins of plants; Arabidopsis thaliana plant cadmium resistance 2 (AtPCR2) acts as a Zn efflux transporter and related with Zn resistance [19].…”

The virome from a collection of endomycorrhizal fungi reveals new viral taxa with unprecedented genome organization

“…2011 ). An ourmia-like virus was shown to be associated with mitochondria ( Hrabáková, Koloniuk, and Petrzik 2017 ) and this fact can provide a possible functional link between virus presence and heavy metal tolerance, since mitochondria are central to heavy metal tolerance in fungi ( Daghino et al. 2019 ).…”

Modulation of Plant and Fungal Gene Expression Upon Cd Exposure and Symbiosis in Ericoid Mycorrhizal Vaccinium myrtillus

“…Similarly, increased metal tolerance was attributed to the fungal partner in ERM plants (Bradley et al, 1981(Bradley et al, , 1982. The cellular and molecular mechanisms that allow ERM fungi to withstand high heavy metal concentrations have been investigated and summarized in Daghino et al (2016Daghino et al ( , 2019 and Ruytinx et al (2016). These studies demonstrate that antioxidant enzymes, metal transporters, DNA damage repair proteins, molecular chaperons and polyamines biosynthesis are involved in the response of the metal tolerant ERM isolate O. maius Zn to metal toxicity.…”