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Prof. Dr. Gerhard Schratt
Institut fÃ¼r Physiologische Chemie
Karl-von-Frisch Str. 1 35032 Marburg
Phone : 06421 28-65020
Fax : --
E-Mail : firstname.lastname@example.org
Web : See online here
Prof. Dr. Christoph Dieterich
UniversitÃ¤t Klinikum Heidelberg
Im Neuenheimer Feld 672, 69120 Heidelberg
Phone : 06221 56-36884
Fax : 06221 56-6868
E-Mail : email@example.com
Web : See online here
MicroRNAs (miRNAs) are arguably the most extensive and best characterized family of small non-coding RNAs that act as important post-transcriptional regulators of gene expression in animals and plants. miRNAs are increasingly acknowledged to play a pivotal role during different steps of synapse development and plasticity in the brain, implicating these molecules in higher cognitive function and related neurological disorders. Work over the last couple of years, including that of our laboratory, led to the identification of specific neuronal miRNAs (e.g. miR-134) which control dendritogenesis and spine morphogenesis by regulating the expression of specific target mRNAs locally in dendrites. However, how neuronal activity modulates miRNA function in dendrites to dynamically control synaptic protein synthesis and plasticity is unknown. In non-neuronal systems, an extensive interplay between miRNAs and sequence-specific RNA-binding proteins (RPBs) was shown in target gene regulation. We conducted a large-scale RNA interference screen for neuronal RBPs and identified 12 RBPs which are required for miR-134 function.
In this project, we intend to study one of these newly identified candidates, Ncoa3 (SRC-3), as a paradigm for a a dynamic miRNA-RBP-interplay in synaptic plasticity and memory function. We hypothesize that activity-dependent Ncoa3 modification could serve as a switch from miRNA repression to the activation of specific target mRNA translation in dendrites. To experimentally test this hypothesis, we will investigate three main objectives. First, we plan to identify genome-wide Ncoa3-regulated miRNA target RNAs in mouse hippocampus using a combination of state-of-the art deep sequencing and bioinformatics. Second, we want to characterize the molecular mechanism underlying activity-dependent regulation of selected Ncoa3 targets using biochemical and live cell imaging approaches. Finally, we want to assess the physiological significance of activity-dependent Ncoa3 regulation for neuronal plasticity and memory formation in mice based on morphological, physiological and behavioral studies.
Together, this multidisciplinary approach promises to provide insight into the mechanism and function of a miRNA-RBP-interplay in neurons, with general implications for stimulus-dependent regulation of ncRNA function in nervous system development, plasticity and disease.
Key equipment :
- Leica SP5 laser-scanning confocal microscope
- Zeiss LSM5 Pascal laser-scanning confocal microscope
- qRT-PCR (ABI)
- Automated luminometer (Promega)
- Electrophysiology rack for patch-clamp and field recordings
- In house SPF animal facility including laboratory for behavioral testing equipped with camera and EthoVision animal tracking software
- Compute infrastructure (high-memory compute nodes, database server and web services)
Beata Stepniak, Anne KÃ¤stner, Giulia Poggi, Marina Mitjans, Martin Begemann, Annette Hartmann, Sandra Van der Auwera, Farahnaz Sananbenesi, Dilja Krueger-Burg, Gabriela Matuszko, Cornelia Brosi, Georg Homuth, Henry VÃ¶lzke, FritzBenseler, Claudia Bagni, Utz Fischer, Alexander Dityatev, Hans-JÃ¶rgen Grabe, DanRujescu, Andre Fischer, Hannelore Ehrenreich. Accumulated common variants in the broader fragile X gene family modulate autistic phenotypes. DOI 10.15252/emmm.201505696| Published online 26.11.2015 EMBO Molecular Medicine (2015) 7, 1565-1579
Schratt G, Tuebing F, Nigh EA, Kane CG, Sabatini ME, Kiebler M and Greenberg ME. (2006) A brain-specific microRNA regulates dendritic spine development. Nature 2006, 439:283-289.
Fiore R.*, Khudayberdiev S.*, Christensen M., Siegel G., Flavell S., Kim T.K., Greenberg M.E. and Schratt G. (2009) Mef2-dependent activation of the miR-379-410 cluster promotes dendritic outgrowth by fine-tuning protein levels of the translational repressor Pumilio2. EMBO J.18;28(6):697-710.
Siegel G.*, Obernosterer G.*, Fiore R., Oehmen, M., Bicker, S., Christensen M., Khudayberdiev, S., Leuschner, P., Busch, C., Kane, C., HÃ¼bel K., Dekker, F., Hedberg, C., Rengarajan, B., Drepper, C., Waldmann H., Kauppinen S., Greenberg M.E., Draguhn, A., Rehmsmeier M., Martinez J. and Schratt G. (2009) A functional microRNA screen implicates miR-138-dependent regulation of the depalmitoylation enzyme APT1 in dendritic spine morphogenesis. Nature Cell Biology, 11(6):705-716.
Christensen, M., Larsen, L.A., Kauppinen S. and Schratt G. (2010) Recombinant Adeno-Associated Virus-mediated delivery into the postnatal mouse brain reveals a role for miR-134 in dendritogenesis in vivo. Front. Neural Circuits 3(16).doi:10.3389/neuro.04.016.2009.
Saba, R., StÃ¶rchel, P.H., Aksoy-Aksel, A., Kepura, F., Lippi, G., Plant, T.D. and Schratt, G. (2012) The dopamine-regulated microRNA, miR-181a, controls GluA2 surface expression in hippocampal neurons. Mol Cell Biol. 32(3):619-32.
Anders G, Mackowiak SD, Jens M, Maaskola J, Kuntzagk A, Rajewsky N, Landthaler M, Dieterich C. (2012) doRiNA: a database of RNA interactions in post-transcriptional regulation. Nucleic Acids Research. 40:D180-6
Baltz AG, Munschauer M, SchwanhÃ¤usser B, Vasile A, Murakawa Y, Schueler M, Youngs N, Penfold-Brown D, Drew K, Milek M, Wyler E, Bonneau R, Selbach M, Dieterich C, Landthaler M. (2012) The mRNA-bound proteome and its global occupancy profile on protein-coding transcripts. Molecular Cell. 46(5):674-90
Bicker, S., Khudayberdiev S., Weiss, K., Zocher, K., Baumeister, S. and Schratt G. (2013) The DEAD-box helicase DHX36 mediates dendritic transport of the neuronal precursor-microRNA-134. Genes Dev. 27(9):991-96.
Ahmed R, Chang Z, Younis AE, Langnick C, Li N, Chen W, Brattig N, Dieterich C. (2013)
Conserved miRNAs are candidate post-transcriptional regulators of developmental
arrest in free-living and parasitic nematodes. Genome Biol Evol. 5(7):1246-60.