Project Details
Projekt
RNA-binding proteins as regulators of non coding RNA function at the synapse
Applicant
Professor Dr. Michael Kiebler
Subject Area
Molecular Biology and Physiology of Neurons and Glial Cells
Term
from 2014 to 2021
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 254897163
RNA-binding proteins (RBPs) regulate key cellular functions, e.g. nuclear RNA processing and modification, RNA export and cytoplasmic localization, translation and degradation. In neurons, RBPs are involved in many distinct steps that ultimately decide on the fate of RNAs within the cell. With the discovery of microRNAs (miRNAs) at synapses and their presence in neuronal RNA granules, it became quickly clear that non-coding RNAs (ncRNA) are important post-transcriptional regulators of gene expression in the brain, where they critically contribute to neurogenesis and synaptic plasticity. Here, the dynamic interplay between trans-acting factors, miRNAs and RBPs, critically contributes to the regulation of target transcripts via their 3-UTRs, enabling the cell to tightly regulate the fate of the mRNA.In the second funding period of this project, we aim to characterize the role of RBPs in regulating miRNA interactions with their mRNA targets. Here we would focus on the brain-specific double-stranded RBP Staufen2 (Stau2) that contributes to dendritic mRNA localization and subsequent local protein synthesis at the activated synapse. To get mechanistic and functional insight into the fascinating interplay between miRNAs and RBPs at the 3-UTR of target mRNAs, we have chosen two high confidence Stau2 targets, i.e. the regulator of small G protein signaling (Rgs4) mRNA and the calmodulin3 (Calm3) mRNA. In aim 1, we will further analyze the dynamic regulation of miR26a/Rgs4 mRNA by Stau2, to determine whether Stau2 and miR-26a regulate Rgs4 3-UTR in an antagonistic fashion. In addition, we will investigate whether the predicted miR-137 binding site located within the retained intron in Calm3 is indeed functional and is used to regulate the Calm3 transcript. Next (aim 2), we aim at investigating whether and how synaptic activity modulates this interaction and how it affects the association and localization of RISC factors, e.g. Mov10, Ago2 and PACT, together with Stau2. Here, we will take advantage of the MS2 RNA imaging system established in the lab to study in cultured primary neurons the assembly/disassembly dynamics of the aforementioned components into miRNPs. Finally, in the long-term aim 3 we will investigate the in vivo physiological function of the miRNA/mRNA/Stau2 interplay by studying their functional contributions both in WT as well as in transgenic rats that are Stau2-deficient in forebrain neurons. In summary, we anticipate that our results will shed new light on how RBPs involved in dendritic mRNA localization and synaptic translation critically control synaptic function by regulating the interaction of ncRNAs with their physiological target mRNAs. This will also advance our understanding of how synapses undergo experience-dependent modifications during learning. We are convinced that this gain of knowledge will not only be important to understand normal brain function, but also various dysfunctions underlying neurological diseases.
DFG Programme
Priority Programmes
