Biology subjects

Mayer, W.

Publications and source records attributed to Mayer, W..

4 recordsLinked to original sources

bioRxiv2026

Two components of the early ASH1 mRNA transport machinery undergo PUN motif-dependent liquid-liquid-phase separation

In eukaryotes, mRNA localization is a widespread mechanism of spatial gene regulation. Amongst the best-studied examples is the directional transport of ASH1 mRNA during mitosis of the budding yeast Saccharomyces cerevisiae. ASH1 mRNA is co-transcriptionally bound by the two RNA-binding proteins She2p and Loc1p and subsequently exported. In the cytoplasm, the adapter She3p binds to She2p forming an active transport complex with the myosin motor Myo4p to mediate actin-dependent transport into the daughter cell. Loc1p stays in the nucleus where it has a second function in ribosome biogenesis. In this study, we map the interaction surface of Loc1p on She2p and observe that it does not interfere with the RNA-binding interface of She2p. Analogous to a previous report on Loc1p and RNA, we could show that also Loc1p and She2p undergo liquid-liquid phase separation (LLPS). This event is caused by electrostatic interactions and can be regulated by the phosphorylation-driven alteration of She2ps oligomeric state. Furthermore, we observed that LLPS formation only requires the PUN motifs of Loc1p and that a ternary Loc1p-RNA-She2p complex also undergoes LLPS. In summary, our findings indicate that Loc1p co-transcriptionally recruits the nuclear ASH1 mRNA-She2p complex to LLPS, while the cytoplasmic Loc1p-lacking She2p-She3p-RNA transport complex does not form such LLPS.

biochemistry↗

bioRxiv2025

The yeast phosphofructokinase β-subunit has ATP-dependent RNA unwinding activity and modulates cell cycle progression

Phosphofructokinase (PFK) is a rate-limiting glycolytic enzyme that also possesses an unexplored RNA binding activity. Here, we show that the - and {beta}-subunits of yeast PFK, encoded by PFK1 and PFK2, respectively, bind hundreds of mRNAs in cells, including ones coding for proteins involved in regulation of mitotic cell cycle. Pkf2p directly binds in a Mg-ATP-dependent manner to short GA-, UC-, AU- and U-rich motifs overrepresented in its mRNA targets. Strikingly, Pfk2p displays directional 5 - 3 double-stranded RNA unwinding activity not seen with Pfk1p. Furthermore, Pfk2p dynamically associates with ribosomes and promotes translation of cell cycle genes. Consequently, pfk2{Delta}, but not pfk1{Delta}, mutant cells show severely delayed G1/S phase transition which is independent of the enzymes glycolytic activity. Our results uncovered a hidden function for the Pfk2 subunit as a translational activator of mitotic cell cycle gene transcripts possibly through energy-dependent RNA unwinding activity.

molecular biology↗

bioRxiv2024

Intrinsically disordered RNA-binding motifs cooperate to catalyze RNA folding and drive phase separation

RNA-binding proteins are essential for gene regulation and the spatial organization of cells. Here, we report that the yeast ribosome biogenesis factor Loc1p is an intrinsically disordered RNA-binding protein with eight repeating positively charged, unstructured nucleic acid binding (PUN) motifs. While a single of these previously undefined motifs stabilizes folded RNAs, multiple copies strongly cooperate to catalyze RNA folding. In the presence of RNA, these multivalent PUN motifs drive phase separation. Proteome-wide searches in pro-and eukaryotes for proteins with similar arrays of PUN motifs reveal a strong enrichment in RNA-mediated processes and DNA remodeling. Thus, PUN motifs are potentially involved in a large variety of RNA-and DNA-related processes by concentrating them in membrane-less organelles. The general function and wide distribution of PUN motifs across species suggests that in an ancient "RNA world" PUN-like motifs may have supported the correct folding of early ribozymes.

biochemistry↗

bioRxiv2018

Simultaneous CO2 and CO methanation using microbes

In this study, we developed a method for simultaneous bio-methanation of CO2 and CO with H2 in a single bioreactor using a combination of carboxydotrophic bacteria and methanogenic archaea for industrial applications. Methanogenic archaea generally use H2 and CO2 to produce methane, whereas very few methanogenic archaea methanize CO, and these grow slowly and consequently produce low reactant gas turnover rates. Thus, to achieve fast and simultaneous transformation of CO and CO2, we identified a combination of carboxydotrophic and hydrogenogenic bacteria and methanogenic archaea that can produce H2 and CO2 from CO, and then methanize CO2 and H2. The present screening experiments identified carboxydotrophic bacteria and methanogenic archaea that can cohabitate at the same thermophilic temperature and pH ranges and in the same growth medium. In these experiments, combinations of Carboxydocella thermautotrophica (DSM 12326), Carboxydocella sporoproducens (DSM 16521), and three thermophilic rod-shaped methanogenic archaeal cultures from MicroPyros GmbH formed unique microbial co-cultures that transformed CO2, H2, and CO to methane. The successful combination of these microbes could be used to gasify biowastes, such as sewage sludge, as alternative sources of hydrogen for microbial power-to-gas processes. Accordingly, gasification under these conditions produced H2-rich gas containing CO2 and CO, theoretically allowing various types of biowastes to be converted to biomethane, which is CO2-neutral, storable, and widely applicable as an energy source.

microbiology↗