Faculty
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Lee, Mihye, Ph.D.Associate Professor, Vice Director of SIMS Research Planning Division
RNA metabolism, Post-transcriptional regulation, Animal development, Animal disease model
Room 207, SIMS
+82-41-413-5015
mihyelee@sch.ac.kr
Exploring the unknowns of gene expression control: Post-transcriptional regulation
Our interest is the understanding of post-transcriptional regulatory networks that control gene expression. The birth of mRNA depends on transcriptional regulation, however, the fate of mRNA is determined by a series of post-transcriptional regulation. Newly synthesized mRNAs are under the control of translation, stability, and subcellular localization, which governs spatial and temporal changes of protein synthesis. The post-transcriptional regulation maintains molecular and cellular homeostasis and plays a critical role in many cell types, especially at synapses in neurons, at the leading edge of migratory cells, and in oocytes and early embryos. Moreover, deregulation and failed coordination of these mechanisms contribute to the developmental defects and pathological conditions.
The most important factors that orchestrate the post-transcriptional regulation are non-coding RNAs and RNA binding proteins. Various kinds of non-coding RNAs, including microRNAs, and more than a thousand RNA binding proteins have been identified so far, and they are known to form a complex together with the target mRNAs through dynamic interactions, which functions as a key regulator of gene expression. But, it still remains largely unknown how they specifically interact to build the regulator module with a certain function and how those regulatory modules control the gene expression and affect the biological processes. We expect to decode post-transcriptional regulatory networks by studying systematically the action mechanism and function of non-coding RNAs and RNA binding proteins.
Research topic I: post-transcriptional regulation for the oocyte-to-embryo transition
At the initial step of animal development, the biological events are directed by maternal mRNAs inherited from oocyte because transcription is almost silent from mature oocytes to early embryos. Mature oocyte stores a lot of dormant mRNAs in the cytoplasm and only allows the specific subset of mRNAs to be translated. Upon fertilization, maternally inherited mRNAs in embryos produce proteins required for the developmental processes without transcription, which makes the embryos ready to use their own genome and establish the zygotic control. Therefore, post-transcriptional control is fundamental in the oocyte-to-embryo transition. Our lab has studied the molecular mechanisms that shape the landscape of gene expression in this development window, using mainly a Drosophila model system with high throughput data analysis.
Research topic II: MicroRNA, a key player of gene expression control
MicroRNAs (miRNAs) are small non-coding RNAs with a length of approximately 22 nucleotides, which regulate the gene expression at the post-transcriptional level. Mature microRNA generated from primary microRNA transcript, constitutes the RNA-induced silencing complex (RISC) through the interaction with Ago and associated cofactors, which induce the mRNA degradation and translational repression by base-pairing with its target mRNAs. MicroRNAs are predicted to control more than 60% of human protein-coding genes, enabling them to play regulatory roles in diverse physiological and pathological processes. Our lab has an interest in the function of microRNA in diverse biological contexts. We are studying the microRNA-mediated gene regulation in adipocyte browning and also in aging using a mouse model.
