Integrated sequencing approach to probe rRNA modification landscape during human embryonic stem cell differentiation

16S ribosomal RNA modification drives transcript-specific translation efficiency.

It is proposed that MraW modification of 16S rRNA enhances translation efficiency in general, and that specific transcripts have evolved structural features that fine-tune protein levels that may be prevalent in bacteria which exhibit uncoupled transcription and translation.

Quantitative single-base m6A profiling reveals dynamic reprogramming, evolutionary conservation and transcriptional regulation in bacteria.

N6-methyladenosine (m6A) is a widespread RNA modification that regulates RNA metabolism in eukaryotes, but its distribution and function in bacteria remain poorly defined. Here, we apply GLORI sequencing to generate single-base resolution transcriptome-wide m6A maps in seven bacterial species. We identify 2,845 m6A sites during exponential growth and find extensive condition-dependent methylation dynamics in three strains. In Pseudomonas syringae, m6A remodeling is associated with virulence-related pathways. Comparative analyses reveal 455 conserved m6A site pairs enriched in genes required for growth, energy metabolism, and transmembrane transport. Integrating methylation, transcript abundance, and RNA stability analyses shows that m6A is associated with reduced mRNA abundance and increased RNA stability. We further identify the rRNA methyltransferases RlmF and RlmJ as bacterial mRNA m6A writers. Together, these findings provide a quantitative atlas of bacterial m6A and establish a foundation for understanding its regulatory and evolutionary roles.

Loss of SNORD104-guided rRNA methylation promotes early adaptation to crizotinib in lung adenocarcinoma

The ribosome, long considered an invariant actor of gene expression, recently emerged as a contributor to translational control through chemical modifications of ribosomal RNAs (rRNAs). These modifications are guided by small nucleolar RNAs (snoRNAs), which direct modifying enzymes to specific rRNA positions. Here, we report that lung adenocarcinoma (LUAD) cells that are resistant to tyrosine kinase inhibitors (TKIs) reshape both their translational program and rRNA 2’O-ribose methylation (2’Ome) profiles. EML4-ALK -positive LUAD cells that are resistant to crizotinib (ALK inhibitor) exhibit reduced global protein synthesis and a change in selective translation of mRNAs, encoding proteins previously linked to resistance. These cells show concomitant reduction in SNORD104 and 2’Ome at its associated 28S_Cm1327 position. Functional studies reveal that SNORD104 depletion abolishes 2’Ome at 28S_Cm1327 without affecting basal translation or cell viability, but enhances both under crizotinib exposure. Moreover, SNORD104 knockdown attenuates caspase activation and PARP cleavage during treatment, supporting reduced cell death. Altogether, our findings support a role for snoRNA-guided rRNA modification as a novel non-genomic mechanism in early adaptive responses to crizotinib therapy in LUAD.

Small RNA Analysis in Cancer Cells.

High-resolution profiling of bacterial transcriptomes by SEnd-seq

Abstract Transcription—the process by which genomic DNA is converted into RNA—is a highly dynamic and tightly controlled process across all domains of life. Although bacteria were once regarded as relatively simple organisms, their transcriptomes are now recognized to be remarkably complex, heterogeneous, and subject to multilayered regulation. Despite the availability of an abundance of sequenced bacterial genomes, a comprehensive understanding of how bacteria tune their transcriptional output to adapt to changing environments remains lacking. To this end, SEnd-seq (simultaneous 5′ and 3′ end sequencing) was developed as a high-throughput approach uniquely capable of simultaneously capturing both 5′ and 3′ ends of individual RNA molecules, enabling the reconstruction of full-length transcripts. By capturing each RNA molecule as a distinct molecular entity with single-nucleotide resolution, SEnd-seq has uncovered previously unrecognized transcriptional features across diverse bacterial species, including even the well-studied Escherichia coli. This method performs robustly across a wide range of RNA species and organisms, including hard-to-lyse pathogens such as Mycobacterium tuberculosis. Moreover, SEnd-seq exhibits high sensitivity for detecting low-abundance RNA and is compatible with various target RNA enrichment strategies, as well as genetic, chemical, and functional perturbations, enabling context-specific transcriptomic analyses. As a versatile and broadly adaptable technology, SEnd-seq provides comprehensive insights into transcriptional regulation, RNA processing, and the coordination between RNA-based processes, thereby uncovering potential targets for antibiotic development. In the present review, we summarize the features and applications of SEnd-seq and discuss its future methodological development and expansion into broader biological and biomedical research contexts.

Unmasking the modified small non-coding RNome: detection strategies for RNA modifications

Abstract RNA molecules carry a wide range of chemical modifications that play key roles in regulating their structure, stability, and function. These modifications are especially abundant in small and non-coding RNAs, such as transfer RNAs (tRNA), ribosomal RNA (rRNA), and related fragments, where they influence processes from translation to gene silencing. However, studying these modifications remains challenging due to the short length of these RNAs, their strong secondary structures, and the high density of chemical marks, all of which can interfere with standard sequencing workflows. This review summarizes current strategies for detecting and mapping RNA modifications in the small RNome. We outline the diversity of RNA classes and their characteristic modification patterns, and then discuss key methodological advances. These include demodification-based sequencing approaches for heavily modified RNAs, targeted chemical and enzymatic methods for site-specific mapping, and emerging direct RNA sequencing technologies that allow analysis of native molecules without prior conversion. We also highlight orthogonal validation techniques used to confirm modification identity and improve reliability. Together, these approaches provide complementary insights, but no single method is sufficient on its own. Careful experimental design and validation therefore remain essential for accurate and comprehensive analysis of RNA modifications.