Biology subjects

Rehfeld, F.

Publications and source records attributed to Rehfeld, F..

3 recordsLinked to original sources

bioRxiv2025

Oxidative stress sensing by the translation elongation machinery promotes production of detoxifying selenoproteins

Selenocysteine, incorporated into polypeptides at recoded termination codons, plays an essential role in redox biology. Using GPX1 and GPX4, selenoenzymes that mitigate oxidative stress, as reporters, we performed genome-wide knockout screens to identify regulators of selenocysteine incorporation. This revealed that selenoprotein production is limited by ribosome collisions that occur at inefficiently decoded selenocysteine codons. Accordingly, slowed translation elongation reduced collisions and enhanced selenocysteine decoding. Oxidative stress also slowed translation elongation and augmented selenoprotein production. We identified translation elongation factor EEF1G as a sensor of oxidized glutathione that couples the cellular redox state to translation elongation rate. Oxidative stress sensing by EEF1G slows translation, enhancing production of detoxifying selenoproteins to restore homeostasis. These findings reveal how programmed ribosome collisions enable gene regulation in response to stress.

molecular biology↗

bioRxiv2024

An ultraconserved snoRNA-like element in long noncoding RNA CRNDE promotes ribosome biogenesis and cell proliferation

Cancer cells frequently upregulate ribosome production to support tumorigenesis. While small nucleolar RNAs (snoRNAs) are critical for ribosome biogenesis, the roles of other classes of noncoding RNAs in this process remain largely unknown. Here we performed CRISPRi screens to identify essential long noncoding RNAs (lncRNAs) in renal cell carcinoma (RCC) cells. This revealed that an alternatively-spliced isoform of lncRNA Colorectal Neoplasia Differentially Expressed containing an ultraconserved element (UCE), referred to as CRNDEUCE, is required for RCC cell proliferation. CRNDEUCE localizes to the nucleolus and promotes 60S ribosomal subunit biogenesis. The UCE of CRNDE functions as an unprocessed C/D box snoRNA that directly interacts with ribosomal RNA precursors. This facilitates delivery of eIF6, a key 60S biogenesis factor, which binds to CRNDEUCE through a sequence element adjacent to the UCE. These findings highlight the functional versatility of snoRNA sequences and expand the known mechanisms through which noncoding RNAs orchestrate ribosome biogenesis.

molecular biology↗

bioRxiv2019

PUMILIO, but not RBMX, binding is required for regulation of genomic stability by noncoding RNA NORAD

NORAD is a highly-conserved and abundant long noncoding RNA (lncRNA) that is required for maintenance of genomic stability in mammals. Although initial characterization of NORAD established it as a negative regulator of PUMILIO (PUM) proteins in the cytoplasm, a nuclear role for NORAD in genome maintenance through an interaction with the RNA binding protein RBMX has also been reported. Here we addressed the relative contributions of NORAD:PUM and NORAD:RBMX interactions to the regulation of genomic stability by this lncRNA. Extensive RNA FISH and fractionation experiments established that NORAD localizes predominantly to the cytoplasm with or without DNA damage. Moreover, genetic rescue experiments demonstrated that PUM binding is required for maintenance of genomic stability by NORAD whereas binding of RBMX is dispensable for this function. These data therefore establish an essential role for the NORAD:PUM interaction in genome maintenance and provide a foundation for further mechanistic dissection of this pathway.

molecular biology↗