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Alternative splicing is one of the major cellular processes that determine the tissue-specific expression of protein variants. However, it remains challenging to identify physiologically relevant and tissue-selective proteins that are generated by alternative splicing. Hence, we investigated the target spectrum of the splicing factor Rbfox1 in the cardiac muscle context in more detail. By using a combination of in silico target prediction and in-cell validation, we identified several focal adhesion proteins as alternative splicing targets of Rbfox1. We focused on the alternative splicing patterns of vinculin (metavinculin isoform) and paxillin (extended paxillin isoform) and identified both as potential Rbfox1 targets. Minigene analyses suggested that both isoforms are promoted by Rbfox1 due to binding in the introns. Focal adhesions play an important role in the cardiac muscle context, since they mainly influence cell shape, cytoskeletal organization, and cell-matrix association. Our data confirmed that depletion of Rbfox1 changed cardiomyoblast morphology, cytoskeletal organization, and multinuclearity after differentiation, which might be due to changes in alternative splicing of focal adhesion proteins. Hence, our results indicate that Rbfox1 promotes alternative splicing of focal adhesion genes in cardiac muscle cells, which might contribute to heart disease progression, where downregulation of Rbfox1 is frequently observed., (© The Author(s) (2024). Published by Oxford University Press on behalf of Journal of Molecular Cell Biology, CEMCS, CAS.)

Intrinsically disordered proteins and regions (IDPs and IDRs) and their importance in biology are becoming increasingly recognized in biology, biochemistry, molecular biology and chemistry textbooks, as well as in current protein science and structural biology curricula. We argue that the sequence → dynamic conformational ensemble → function principle is of equal importance as the classical sequence → structure → function paradigm. To highlight this point, we describe the IDPs and/or IDRs behind the discoveries associated with 17 Nobel Prizes, 11 in Physiology or Medicine and 6 in Chemistry. The Nobel Laureates themselves did not always mention that the proteins underlying the phenomena investigated in their award-winning studies are in fact IDPs or contain IDRs. In several cases, IDP- or IDR-based molecular functions have been elucidated, while in other instances, it is recognized that the respective protein(s) contain IDRs, but the specific IDR-based molecular functions have yet to be determined. To highlight the importance of IDPs and IDRs as general principle in biology, we present here illustrative examples of IDPs/IDRs in Nobel Prize-winning mechanisms and processes., (© 2022. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Over recent years, the long known class of small nucleolar RNAs (snoRNAs) have gained interest among the scientific community, especially in the clinical context. The main molecular role of this interesting family of non-coding RNAs is to serve as scaffolding RNAs to mediate site-specific RNA modification of ribosomal RNAs (rRNAs) and small nuclear RNAs (snRNAs). With the development of new sequencing techniques and sophisticated analysis pipelines, new members of the snoRNA family were identified and global expression patterns in disease backgrounds could be determined. We will herein shed light on the current research progress in snoRNA biology and their clinical role by influencing disease outcome in hematological diseases. Astonishingly, in recent studies snoRNAs emerged as potent biomarkers in a variety of these clinical setups, which is also highlighted by the frequent deregulation of snoRNA levels in the hema-oncological context. However, research is only starting to reveal how snoRNAs might influence cellular functions and the connected disease hallmarks in hematological malignancies.