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4. Katja Burk

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Biography

I studied biology at the University of Hohenheim (Stuttgart) and did my diploma thesis at the Max-Planck-Institute for Neurobiology in Martinsried, Munich. I then moved to Cardiff, UK to obtain my PhD in developmental neurobiology, followed by two postdoctoral positions at the IBDML in Marseille, Luminy, France. I returned to Germany in 2014 on an independent postdoctoral position at the European Neuroscience Institute (ENI) in Göttingen. In 2017, I became a group leader within the department of neurology at the University Medical Center Göttingen and I am still running my team in Göttingen. In July 2022 I was appointed as a lecturer in the School of Biochemistry and Cell Biology at UCC. ‍

Research Interests

Our group focuses on how activated receptors transmit their signals within neurons, an essential process during development and – if this process is failing- in neurodegeneration. During the development of neural circuits, neurites grow toward their targets guided by cues in the extracellular environment. These cues are sensed by receptors at the surface that trigger intracellular signaling event, modulating the cytoskeleton. This direction-mediated process allows neurons to find and innervate their appropriate targets in order to form functional synapses. Remarkably, our nervous system contains trillions of connections but only a few hundred growth/guidance cues. Therefore, one important question is how this small number of cues coordinates the wiring of a disproportionally large number of connections. This process is regulated through diversification- a mechanism that amplifies the number of signaling decisions a neuron can make. For example, we found that receptors are able to change their downstream signaling targets over time, which allows adaptation to the required developmental demands. Further, diversification can also occur on the level of endosomes. Here, receptors can be re-routed from one endosomal pathway into another and therefore regulate different functional outcomes (e.g. ensuring neuronal survival vs synapse maturation).Diversification can also occur through retrieval versus degradation of receptors. While the signaling of some receptors is terminated through degradation, other receptors are retrieved from the degradative pathway in order to start their signaling. This mechanism ensures that receptors only signal at specific locations (e.g. at the soma or at the distal end).Another mechanism which we study is the integration of signaling. While diversification amplifies the number of signalling decisions, integration merges signalling pathways which eventually affect the level of the cytoskeleton. The cytoskeleton is a key regulator in trafficking as it ensures movement of cargo from distal to proximal ends and back. Defects of the cytoskeleton affect trafficking in neurons- but also signaling from e.g. trophic receptors affect the stability of the cytoskeleton. Therefore, when studying receptor sorting and signaling, we study the effects on the cytoskeleton at the same time. Our findings are then applied translationally to study neurodegenerative diseases such as Charcot-Marie-Tooth disease and Amyothrophic Lateral Sclerosis. To answer the above questions, we use model systems such as primary neurons from mouse and chick, iPSC-derived sensory and motor neurons and apply several imaging techniques (e.g. confocal, total internal reflection fluorescence (TIRF), stimulated emission depletion (STED), electron- or spinning-disk microscopy) and biochemistry.

Research Grants

	Project	Funding Body	Start Date	End Date	Award
	EndophilinAs regulate endosomal sorting of BDNF-TrkB to mediate survival signaling in hippocampal neurons	Other: Not Listed	01-FEB-15	30-JUN-17
	DFG Cluster of Excellence University Medical Center Göttingen	Other: Not Listed	01-JUL-17	31-DEC-18
	Receptor sorting through tubular microdomains of Rab7-positive endosomes in Charcot- Marie-Tooth disease 2B	Other: Not Listed	01-JUL-19
	Role of endophilins on endosomal transport	Deutscher Akademischer Austausch Dienst (DAAD)	15-JUL-14	31-JAN-15
	Activated receptor sorting in development and disease	Other: Not Listed	01-JUL-19	30-JUN-22
	Pathomechanisms in Amyotrophic Lateral Sclerosis	Other: Not Listed	01-NOV-21

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Publications

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Books

	Year	Publication
	(2022)	The endocytosis, trafficking, sorting and signaling of neurotrophic receptors. Katja Burk (2022) The endocytosis, trafficking, sorting and signaling of neurotrophic receptors. Netherlands: Elsevier.   [DOI] [Details]

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Peer Reviewed Journals

	Year	Publication
	(2021)	'Axon guidance receptors: Endocytosis, trafficking and downstream signaling from endosomes' Pasterkamp RJ;Burk K; (2021) 'Axon guidance receptors: Endocytosis, trafficking and downstream signaling from endosomes'. Progress In Neurobiology, 198 [DOI] [Details]
	(2021)	'Held Up in Traffic-Defects in the Trafficking Machinery in Charcot-Marie-Tooth Disease' Markworth R;Bähr M;Burk K; (2021) 'Held Up in Traffic-Defects in the Trafficking Machinery in Charcot-Marie-Tooth Disease'. Frontiers in molecular neuroscience, 14 [DOI] [Details]
	(2021)	'Tubular microdomains of Rab7-positive endosomes retrieve TrkA, a mechanism disrupted in Charcot-Marie-Tooth disease 2B' Markworth R;Dambeck V;Steinbeck LM;Koufali A;Bues B;Dankovich TM;Wichmann C;Burk K; (2021) 'Tubular microdomains of Rab7-positive endosomes retrieve TrkA, a mechanism disrupted in Charcot-Marie-Tooth disease 2B'. Journal of Cell Science, 134 (20) [DOI] [Details]
	(2019)	'Disrupted neuronal trafficking in amyotrophic lateral sclerosis' Burk K;Pasterkamp RJ; (2019) 'Disrupted neuronal trafficking in amyotrophic lateral sclerosis'. Acta Neuropathologica, 137 (6) [DOI] [Details]
	(2019)	'Synaptotagmin-3 drives AMPA receptor endocytosis, depression of synapse strength, and forgetting' Awasthi A;Ramachandran B;Ahmed S;Benito E;Shinoda Y;Nitzan N;Heukamp A;Rannio S;Martens H;Barth J;Burk K;Wang YT;Fischer A;Dean C; (2019) 'Synaptotagmin-3 drives AMPA receptor endocytosis, depression of synapse strength, and forgetting'. Science, 363 (6422) [DOI] [Details]
	(2019)	'Sensory Axon Growth Requires Spatiotemporal Integration of CaSR and TrkB Signaling' Markworth R;Adolfs Y;Dambeck V;Steinbeck LM;Lizé M;Pasterkamp RJ;Bähr M;Dean C;Burk K; (2019) 'Sensory Axon Growth Requires Spatiotemporal Integration of CaSR and TrkB Signaling'. The Journal of Neuroscience, 39 (30) [DOI] [Details]
	(2018)	'Regulation of Dendritic Spine Morphology in Hippocampal Neurons by Copine-6' Burk K;Ramachandran B;Ahmed S;Hurtado-Zavala JI;Awasthi A;Benito E;Faram R;Ahmad H;Swaminathan A;McIlhinney J;Fischer A;Perestenko P;Dean C; (2018) 'Regulation of Dendritic Spine Morphology in Hippocampal Neurons by Copine-6'. Cerebral cortex (New York, N.Y. : 1991), 28 (4) [DOI] [Details]
	(2017)	'EndophilinAs regulate endosomal sorting of BDNF-TrkB to mediate survival signaling in hippocampal neurons' Burk K;Murdoch JD;Freytag S;Koenig M;Bharat V;Markworth R;Burkhardt S;Fischer A;Dean C; (2017) 'EndophilinAs regulate endosomal sorting of BDNF-TrkB to mediate survival signaling in hippocampal neurons'. Scientific Reports, 7 (1) [DOI] [Details]
	(2017)	'Post-endocytic sorting of Plexin-D1 controls signal transduction and development of axonal and vascular circuits' Burk K;Mire E;Bellon A;Hocine M;Guillot J;Moraes F;Yoshida Y;Simons M;Chauvet S;Mann F; (2017) 'Post-endocytic sorting of Plexin-D1 controls signal transduction and development of axonal and vascular circuits'. Nature Communications, 8 [DOI] [Details]
	(2017)	'Capture of Dense Core Vesicles at Synapses by JNK-Dependent Phosphorylation of Synaptotagmin-4' Bharat V;Siebrecht M;Burk K;Ahmed S;Reissner C;Kohansal-Nodehi M;Steubler V;Zweckstetter M;Ting JT;Dean C; (2017) 'Capture of Dense Core Vesicles at Synapses by JNK-Dependent Phosphorylation of Synaptotagmin-4'. Cell Reports, 21 (8) [DOI] [Details]
	(2013)	'Navigation rules for vessels and neurons: cooperative signaling between VEGF and neural guidance cues' Chauvet S;Burk K;Mann F; (2013) 'Navigation rules for vessels and neurons: cooperative signaling between VEGF and neural guidance cues'. Cellular and Molecular Life Sciences, 70 (10) [DOI] [Details]
	(2012)	'Agrin-signaling is necessary for the integration of newly generated neurons in the adult olfactory bulb' Burk K.;Desoeuvre A.;Boutin C.;Smith M.A.;Kröger S.;Bosio A.;Tiveron M.C.;Cremer H. (2012) 'Agrin-signaling is necessary for the integration of newly generated neurons in the adult olfactory bulb'. The Journal of Neuroscience, 32 (11):3759-3764 [DOI] [Details]
	(2011)	'Ephrin Bs are essential components of the Reelin pathway to regulate neuronal migration' Sentürk A;Pfennig S;Weiss A;Burk K;Acker-Palmer A; (2011) 'Ephrin Bs are essential components of the Reelin pathway to regulate neuronal migration'. Nature, 472 (7343) [DOI] [Details]