Biology subjects

Sobanska, D.

Publications and source records attributed to Sobanska, D..

3 recordsLinked to original sources

bioRxiv2021

An mRNA silencing mechanism reliant on the cooperation between REGE-1/Regnase-1 and RLE-1/Roquin-1

Regnase-1 is an evolutionarily conserved endoribonuclease, degrading diverse mRNAs important, among others, for immune homeostasis, development, and cancer. There are two competing models of Regnase-1 mediated mRNA silencing. One model postulates that Regnase-1 works together with another RNA-binding protein, Roquin-1. The other model proposes that the two proteins function separately. Studying the C. elegans Regnase-1 ortholog, REGE-1, we have uncovered a functional relationship between REGE-1 and the nematode counterpart of Roquin-1, RLE-1. While REGE-1 and RLE-1 associate with mRNA independently of each other, both proteins are essential for mRNA silencing. Intriguingly, the functional interdependence between REGE-1 and RLE-1 is reminiscent of the proposed cooperation between mammalian Regnase-1 and Roquin-1, which may underlie a prototypic silencing mechanism involving both proteins.

molecular biology↗

bioRxiv2021

Bacterial chaperone protein Hfq facilitates the annealing of sponge RNAs to small regulatory RNAs

Bacterial small RNAs (sRNAs) in association with the chaperone protein Hfq regulate the expression of many target mRNAs. Since sRNAs action is crucial to engender a response to changing environmental conditions, their activity needs to be regulated. One such mechanism occurs at posttranscriptional level and involves sponge RNAs (or anti-sRNAs) which sequester sRNAs affecting their regulatory output. Both types of RNAs were identified on Hfq, but it is not known how Hfq interacts with RNA sponges and stimulates their base-pairing with sRNAs. Here, we used biochemical methods to demonstrate that anti-sRNAs resemble sRNAs by their structure and their modes of Hfq binding. Hfq facilitates sponge RNA annealing to sRNA, and each surface of the protein plays a particular role in the process. Moreover, we found that the efficiency of sponge RNA interactions with sRNAs can be improved, therefore, we propose that natural RNA sponges might not sequester sRNAs optimally.

molecular biology↗

bioRxiv2021

Surviving hypothermia by ferritin-mediated iron detoxification

How animals rewire cellular programs to survive cold is a fascinating problem with potential biomedical implications, ranging from emergency medicine to space travel. Studying a hibernation-like response in the free-living nematode Caenorhabditis elegans, we uncovered a regulatory axis that enhances the natural resistance of nematodes to severe cold. This axis involves conserved transcription factors, DAF-16/FoxO and PQM-1, which jointly promote cold survival by upregulating FTN-1, a protein related to mammalian Fth1/ferritin. Moreover, we show that inducing expression of Fth1 also promotes cold survival of mammalian neurons, a cell type particularly sensitive to deterioration in hypothermia. Our findings in both animals and cells suggest that FTN-1/Fth1 facilitates cold survival by detoxifying ROS-generating iron species. We finally show that mimicking the effects of FTN-1/Fth1 with drugs protects neurons from cold-induced degeneration, opening a potential avenue to improved treatments of hypothermia.

physiology↗