Snapshot Moments of the Cell Revealed by UV-Crosslinking and RNA Co-immunoprecipitation of Transient RNA-Protein Complexes.

RNA co-immunoprecipitation serves as a powerful technique for elucidating the interactions between RNA and RNA-binding proteins, pivotal for understanding posttranscriptional regulation mechanisms. This method captures the dynamics of protein-RNA associations across various cellular processes, applicable to both coding and noncoding RNAs. Here we describe a convenient and compelling method using nanobody coupled beads and UV-crosslinking.

Defenders of the Transcriptome: Guard Protein-Mediated mRNA Quality Control in .

Cell survival depends on precise gene expression, which is controlled sequentially. The guard proteins surveil mRNAs from their synthesis in the nucleus to their translation in the cytoplasm. Although the proteins within this group share many similarities, they play distinct roles in controlling nuclear mRNA maturation and cytoplasmic translation by supporting the degradation of faulty transcripts.

dsRNA formation leads to preferential nuclear export and gene expression.

When mRNAs have been transcribed and processed in the nucleus, they are exported to the cytoplasm for translation. This export is mediated by the export receptor heterodimer Mex67-Mtr2 in the yeast Saccharomyces cerevisiae (TAP-p15 in humans). Interestingly, many long non-coding RNAs (lncRNAs) also leave the nucleus but it is currently unclear why they move to the cytoplasm.

The DEAD-box RNA helicase Dbp5 is a key protein that couples multiple steps in gene expression.

Cell viability largely depends on the surveillance of mRNA export and translation. Upon pre-mRNA processing and nuclear quality control, mature mRNAs are exported into the cytoplasm via Mex67-Mtr2 attachment. At the cytoplasmic site of the nuclear pore complex, the export receptor is displaced by the action of the DEAD-box RNA helicase Dbp5.

Surveillance of 3' mRNA cleavage during transcription termination requires CF IB/Hrp1.

CF IB/Hrp1 is part of the cleavage and polyadenylation factor (CPF) and cleavage factor (CF) complex (CPF-CF), which is responsible for 3' cleavage and maturation of pre-mRNAs. Although Hrp1 supports this process, its presence is not essential for the cleavage event. Here, we show that the main function of Hrp1 in the CPF-CF complex is the nuclear mRNA quality control of proper 3' cleavage.