Biology subjects

Petrova, M.

Publications and source records attributed to Petrova, M..

4 recordsLinked to original sources

bioRxiv2023

BRD2 and BRD3 genes independently evolved RNA structures to control unproductive splicing

The mammalian BRD2 and BRD3 genes encode structurally related proteins from the bromodomain and extraterminal domain (BET) protein family. The expression of BRD2 is regulated by unproductive splicing upon inclusion of exon 3b, which is located in the region encoding a bromodomain. Bioinformatic analysis indicated that BRD2 exon 3b inclusion is controlled by a pair of conserved complementary regions (PCCR) located in the flanking introns. Furthermore, we identified a highly conserved element encoding a cryptic poison exon 5b and a previously unknown PCCR in the intron between exons 5 and 6 of BRD3, however outside of the homologous bromodomain. Minigene mutagenesis and blockage of RNA structure by antisense oligonucleotides demonstrated that RNA structure controls the rate of inclusion of poison exons. The patterns of BRD2 and BRD3 expression and splicing show downregulation upon inclusion of poison exons, which become skipped in response to transcription elongation slowdown, further confirming a role of PCCRs in unproductive splicing regulation. We conclude that BRD2 and BRD3 independently acquired poison exons and RNA structures to dynamically control unproductive splicing. This study describes a convergent evolution of regulatory unproductive splicing mechanisms in these genes providing implications for selective modulation of their expression in therapeutic applications.

bioinformatics↗

bioRxiv2022

RNA in situ conformation sequencing reveals novel long-range RNA structures with impact on splicing

Over past years, long-range RNA structure has emerged as a factor that is fundamental to alternative splicing regulation. Since an increasing number of human disorders are now being associated with splicing defects, it is essential to develop methods that assess long-range RNA structure experimentally. RNA in situ conformation sequencing (RIC-seq) is the method that recapitulates RNA structure within physiological RNA-protein complexes. In this work, we juxtapose RIC-seq experiments conducted in eight human cell lines with pairs of conserved complementary regions (PCCRs) that were predicted in silico. We show statistically that RIC-seq support strongly correlates with PCCR properties such as equilibrium free energy, presence of compensatory substitutions, and occurrence of A-to-I RNA editing sites and forked eCLIP peaks. Based on these findings, we prioritize PCCRs according to their RIC-seq support and show experimentally using antisense nucleotides and minigene mutagenesis that PCCRs in two disease-associated genes, PHF20L1 and CASK, impact alternative splicing. In sum, we demonstrate how RIC-seq experiments can be used to discover functional long-range RNA structures, and particularly those that regulate alternative splicing.

molecular biology↗

bioRxiv2020

pAgo-induced DNA interference protects bacteria from invader DNA

Members of the conserved Argonaute protein family use small RNA guides to find their mRNA targets to regulate gene expression and suppress mobile genetic elements in eukaryotes. Argonautes are also present in many bacterial and archaeal species 1-3. Unlike eukaryotic proteins, several studied prokaryotic Argonautes use small DNA guides to cleave DNA, a process dubbed DNA interference 4-8. However, the natural functions and targets of DNA interference are poorly understood and the mechanisms of DNA guide generation and target discrimination remain unknown. Here, we studied the in vivo activities of a bacterial Argonaute nuclease CbAgo and demonstrated that it induces cleavage of multicopy genetic elements, including plasmids, transposons and repetitive chromosomal loci. Generation of small DNA guides employed by CbAgo requires cooperation between its intrinsic endonuclease activity and the cellular double-strand break repair machinery. The mechanism of guide generation ensures that small DNA guides are enriched in sequences that target foreign DNA and endows CbAgo with capacity to eliminate plasmids and fight phage infection. Similar principles may underlie the specificity of self-nonself discrimination by diverse defense systems in prokaryotes.

molecular biology↗

bioRxiv2019

Evidence for Early European Neolithic Dog Dispersal: New Data on South-Eastern European subfossil dogs from Prehistory and Antiquity Ages

ObjectivesThe history of dog domestication is still under debate, but doubtlessly, it is a process of an ancient partnership between dogs (Canis familiaris) and humans. Although data on ancient DNA dog diversity are scarce, it is clear that several regional dog populations had been formed in Eurasia up to the Holocene. During the Neolithic Revolution and the transition from hunter-gatherer to farmer societies, followed by civilization changes in the Antiquity period, the dog population structure also changed. This process was due to replacement with newly formed dog breeds.\n\nMethodsIn this study we have presented for the first time mitochondrial data about South-Eastern Europe (the Balkans) ancient dog remains from the Early Neolithic (8 000 years BP) to the Late Antiquity ages (up to 3th century AD). A total of 25 samples were analyzed using the mitochondrial D-loop region (HVR1).\n\nResultsThe results have shown the presence of A (70%) and B (25%) clades throughout the whole investigated period. In order to clarify the position of our results within the ancient dog population in Eneolithic Eurasia, we performed phylogenetic analysis with the available genetic data sets. This data revealed a similarity of the Bulgarian dogs structure to that of ancient Italian dogs (A, B, and C clades), which suggests a new prehistoric and historic Mediterranean dog population. A clear border can be seen between South-European genetic dog structure, on the one hand, and, on the other hand, Central-West (clade C), East (clade D) and North Europe (clades A and C). This corresponds to genetic data for European humans during the same period without admixture between dog populations.\n\nConclusionsOur data have shown for the first time the presence of clade B in ancient Eurasia. This is not unexpected as the B haplogroup is widely distributed in extant Balkan dogs and wolves. The presence of this clade both in dogs and in wolves on the Balkans may be explained with hybridization events before the Neolithic period. The spreading of this clade across Europe together with the A clade is related to the possible dissemination of newly formed dog breeds from Ancient Greece, Thrace and the Roman Empire.

evolutionary biology↗