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7 results on '"Nowak, Jakub Stanislaw"'

1. Dual role of Lin28a in the regulation of miRNA biogenesis during neuronal differentiation

Author

Nowak, Jakub Stanislaw, Michlewski, Gracjan, and Tollervey, David

Subjects
572.8, miRNA, neuronal differentiation, RNA processing
Abstract

Many cellular functions depend on the tightly regulated expression of various proteins. Canonical control of the protein expression is associated with transcriptional regulation. However, the small non-coding RNAs called microRNAs (miRNAs) were identified as post-transcriptional regulators of gene expression. In a typical manner, miRNAs originate similarly to the coding RNAs and are processed in a multi-step maturation process. It has been shown that miRNAs are very important for the proper functioning of tissues. Interestingly, the human nervous system contains over 70% of all miRNAs; thus, the maturation process has to be tightly regulated. However, despite the important role of miRNAs, little is known about the mechanisms regulating their biogenesis. In my PhD project, I showed that during early stages of neuronal differentiation, Lin28a controls levels of neuro-specific miRNA-9. I demonstrated that Lin28a binds to the conserved terminal loop (CTL) of pre-miRNA-9 and decreases the cellular levels of miRNA-9 during retinoic acid-mediated neuronal differentiation of mouse teratocarcinoma P19 cells. I revealed that the Lin28a-mediated inhibition of miRNA-9 production was uridylation-independent. Furthermore, constitutive expression of GFP-tagged Lin28a reduced the levels of let-7a but not miRNA-9, whereas untagged Lin28a inhibited both miR-9 and let-7a during the course of neuronal differentiation. Using small RNAseq analysis of P19 cells with constitutive expression of Lin28a I showed that it controls many more miRNAs than previously recognised. Intriguingly, many miRNAs were upregulated by Lin28a overexpression. I demonstrated with high-throughput, the limited function of GFP-tagged Lin28a results, and I also showed that untagged Lin28a inhibits the production of a number of brain-specific miRNAs including miRNA-9. Finally, I revealed that 3’-5’exoribonuclease Dis3l2 was responsible for uridylation-independent degradation of pre-miRNA-9. Altogether, my results provided evidence that Lin28a has both positive and negative roles in the regulation of miRNA production and has a dual role in triggering pre-miRNA degradation.

Published
2016

3. Lin28a uses distinct mechanisms of binding to RNA and affects miRNA levels positively and negatively

Author

Nowak, Jakub Stanislaw, Hobor, Fruzsina, Downie Ruiz Velasco, Angela, Choudhury, Nila Roy, Heikel, Gregory, Kerr, Alastair, Ramos, Andres, and Michlewski, Gracjan

Subjects
Neurons, Pluripotent Stem Cells, Poly U, RNA Cleavage, Base Sequence, Recombinant Fusion Proteins, Green Fluorescent Proteins, RNA-Binding Proteins, Cell Differentiation, RNA Nucleotidyltransferases, Tretinoin, Article, DNA-Binding Proteins, Mice, MicroRNAs, Gene Expression Regulation, Cell Line, Tumor, Exoribonucleases, RNA Precursors, Animals, Humans, Nucleic Acid Conformation, Base Pairing, HeLa Cells, Protein Binding
Abstract

Lin28a inhibits the biogenesis of let-7 miRNAs by triggering the polyuridylation and degradation of their precursors by terminal uridylyltransferases TUT4/7 and 3'-5' exoribonuclease Dis3l2, respectively. Previously, we showed that Lin28a also controls the production of neuro-specific miRNA-9 via a polyuridylation-independent mechanism. Here we reveal that the sequences and structural characteristics of pre-let-7 and pre-miRNA-9 are eliciting two distinct modes of binding to Lin28a. We present evidence that Dis3l2 controls miRNA-9 production. Finally, we show that the constitutive expression of untagged Lin28a during neuronal differentiation in vitro positively and negatively affects numerous other miRNAs. Our findings shed light on the role of Lin28a in differentiating cells and on the ways in which one RNA-binding protein can perform multiple roles in the regulation of RNA processing.

Published
2017

4. Lin28a uses distinct mechanisms of binding to RNA and affects positively and negatively miRNA levels

Author

Hobor, Fruzsina, Nowak, Jakub Stanislaw, Velasco, Angela, Choudhurry, Nila, Heikel, Gregory, Kerr, Alastair, Ramos, Andres, and Michlewski, Gracjan

Subjects
Lin28a, miRNA-9, let-7, neuronal differentiation
Abstract

Lin28a inhibits the biogenesis of let-7 miRNAs by triggering the polyuridylation and degradation of their precursors by terminal uridylyltransferases TUT4/7 and 3’-5’ exoribonuclease Dis3l2, respectively. Previously, we showed that Lin28a also controls the production of neuro-specific miRNA-9 via a polyuridylation-independent mechanism. Here we reveal that the sequences and structural characteristics of pre-let-7 and pre-miRNA-9 are eliciting two distinct modes of binding to Lin28a. We present evidence that Dis3l2 controls miRNA-9 production. Finally, we show that the constitutive expression of untagged Lin28a during neuronal differentiation in vitro positively and negatively affects numerous other miRNAs. Our findings shed light on the role of Lin28a in differentiating cells and on the ways in which one RNA-binding protein can perform multiple roles in the regulation of RNA processing.

Published
2017

7. Lin28a uses distinct mechanisms of binding to RNA and affects miRNA levels positively and negatively.

Author

Nowak JS, Hobor F, Downie Ruiz Velasco A, Choudhury NR, Heikel G, Kerr A, Ramos A, and Michlewski G

Subjects
Animals, Base Pairing, Base Sequence, Cell Differentiation drug effects, Cell Line, Tumor, DNA-Binding Proteins genetics, DNA-Binding Proteins metabolism, Exoribonucleases metabolism, Gene Expression Regulation, Green Fluorescent Proteins genetics, Green Fluorescent Proteins metabolism, HeLa Cells, Humans, Mice, MicroRNAs metabolism, Neurons cytology, Neurons drug effects, Nucleic Acid Conformation, Pluripotent Stem Cells cytology, Pluripotent Stem Cells drug effects, Pluripotent Stem Cells metabolism, Poly U metabolism, Protein Binding, RNA Cleavage, RNA Nucleotidyltransferases genetics, RNA Nucleotidyltransferases metabolism, RNA Precursors metabolism, RNA-Binding Proteins metabolism, Recombinant Fusion Proteins genetics, Recombinant Fusion Proteins metabolism, Tretinoin pharmacology, Exoribonucleases genetics, MicroRNAs genetics, Neurons metabolism, RNA Precursors genetics, RNA-Binding Proteins genetics
Abstract

Lin28a inhibits the biogenesis of let-7 miRNAs by triggering the polyuridylation and degradation of their precursors by terminal uridylyltransferases TUT4/7 and 3'-5' exoribonuclease Dis3l2, respectively. Previously, we showed that Lin28a also controls the production of neuro-specific miRNA-9 via a polyuridylation-independent mechanism. Here we reveal that the sequences and structural characteristics of pre-let-7 and pre-miRNA-9 are eliciting two distinct modes of binding to Lin28a. We present evidence that Dis3l2 controls miRNA-9 production. Finally, we show that the constitutive expression of untagged Lin28a during neuronal differentiation in vitro positively and negatively affects numerous other miRNAs. Our findings shed light on the role of Lin28a in differentiating cells and on the ways in which one RNA-binding protein can perform multiple roles in the regulation of RNA processing., (© 2017 Nowak et al.; Published by Cold Spring Harbor Laboratory Press for the RNA Society.)

Published
2017
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