Thesis Type: Postgraduate
Institution Of The Thesis: Yildiz Technical University, Faculty Of Chemıcal And Metallurgıcal Engıneerıng, Department Of Bioengineering, Turkey
Approval Date: 2022
Thesis Language: English
Student: ELİF İREM KELEŞ
Supervisor: Alper Yılmaz
Abstract:
Non-coding RNAs are group of RNA that have various roles at transcriptional and post-transcriptional levels and they comprise majority of human human. CircRNAs are non-coding RNA groups which gained attention recently. circular RNAs are single stranded, circular and covalently closed RNA molecules. Because of its circular structure, CircRNAs cannot code proteins. Upon their initial discovery circRNAs were considered as splicing error in viroids. Ever increasing researches showed that CircRNAs interact with other non-coding RNAs (e.g. miRNA) and proteins (e.g. RBPs), and they are associated with epigenetic changes. Although biological functions of circRNAs are brought to light by ongoing research, uncertainties about their biogenesis still exist. CircRNAs are produced from pre mRNAs by mechanism called back splicing, which is considered a distinct splicing mechanism compared to alternative splicing. In order to have circular form, two edges of circRNAs (5’ donor and 3’ acceptor site) need to be connected. Exons and flanking introns forming the circRNA may affect both structure and type of circRNA. Because formation of circRNA depends on many factors, biogenesis of circRNAs is yet to be fully understood. Since circRNAs are constructed from pre-mRNAs, it is at least expected that a correlation exists between parent gene expression and circRNA level. In this study, gene expression and circRNA expression data for various tissues were retrieved from circAtlas 2.0 database. After filtering genes and circRNAs that are expressed in specific tissues a striking result was observed. For certain circRNAs, parent geneof the circRNA have been expressed in different tissues. In our study we focused on Uterus tissue to investigate the phenomenon. Samples which contain circRNA expression but parent gene expressions have been detected and RBPs which have potential of binding to region of parent gene transcript that constitute the circular RNA were identified by integrating results of e-CLIP and RNA bind N seq data acquired from ENCODE project. Our results shed light on biogenesis of circRNAs. RBPs have potential to interact with certain parent gene transcripts and direct all of them to back splice into circRNAs. Thus, the potential of circRNA in diagnosis and treatment of diseases in uterus and role of parent gene in circRNA biogenesis will have been much better understood.