TY  - JOUR
A1  - Mrestani, Achmed
A1  - Pauli, Martin
A1  - Kollmannsberger, Philip
A1  - Repp, Felix
A1  - Kittel, Robert J.
A1  - Eilers, Jens
A1  - Doose, Sören
A1  - Sauer, Markus
A1  - Sirén, Anna-Leena
A1  - Heckmann, Manfred
A1  - Paul, Mila M.
T1  - Active zone compaction correlates with presynaptic homeostatic potentiation
JF  - Cell Reports
N2  - Neurotransmitter release is stabilized by homeostatic plasticity. Presynaptic homeostatic potentiation (PHP) operates on timescales ranging from minute- to life-long adaptations and likely involves reorganization of presynaptic active zones (AZs). At Drosophila melanogaster neuromuscular junctions, earlier work ascribed AZ enlargement by incorporating more Bruchpilot (Brp) scaffold protein a role in PHP. We use localization microscopy (direct stochastic optical reconstruction microscopy [dSTORM]) and hierarchical density-based spatial clustering of applications with noise (HDBSCAN) to study AZ plasticity during PHP at the synaptic mesoscale. We find compaction of individual AZs in acute philanthotoxin-induced and chronic genetically induced PHP but unchanged copy numbers of AZ proteins. Compaction even occurs at the level of Brp subclusters, which move toward AZ centers, and in Rab3 interacting molecule (RIM)-binding protein (RBP) subclusters. Furthermore, correlative confocal and dSTORM imaging reveals how AZ compaction in PHP translates into apparent increases in AZ area and Brp protein content, as implied earlier.
KW  - active zone
KW  - Bruchpilot
KW  - RIM-binding protein
KW  - compaction
KW  - homeostasis
KW  - presynaptic plasticity
KW  - super-resolution microscopy
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-265497
VL  - 37
IS  - 1
ER  - 
TY  - JOUR
A1  - Kuhlemann, Alexander
A1  - Beliu, Gerti
A1  - Janzen, Dieter
A1  - Petrini, Enrica Maria
A1  - Taban, Danush
A1  - Helmerich, Dominic A.
A1  - Doose, Sören
A1  - Bruno, Martina
A1  - Barberis, Andrea
A1  - Villmann, Carmen
A1  - Sauer, Markus
A1  - Werner, Christian
T1  - Genetic Code Expansion and Click-Chemistry Labeling to Visualize GABA-A Receptors by Super-Resolution Microscopy
JF  - Frontiers in Synaptic Neuroscience
N2  - Fluorescence labeling of difficult to access protein sites, e.g., in confined compartments, requires small fluorescent labels that can be covalently tethered at well-defined positions with high efficiency. Here, we report site-specific labeling of the extracellular domain of γ-aminobutyric acid type A (GABA-A) receptor subunits by genetic code expansion (GCE) with unnatural amino acids (ncAA) combined with bioorthogonal click-chemistry labeling with tetrazine dyes in HEK-293-T cells and primary cultured neurons. After optimization of GABA-A receptor expression and labeling efficiency, most effective variants were selected for super-resolution microscopy and functionality testing by whole-cell patch clamp. Our results show that GCE with ncAA and bioorthogonal click labeling with small tetrazine dyes represents a versatile method for highly efficient site-specific fluorescence labeling of proteins in a crowded environment, e.g., extracellular protein domains in confined compartments such as the synaptic cleft.
KW  - super-resolution microscopy (SRM)
KW  - click-chemistry
KW  - dSTORM
KW  - GABA-A receptor
KW  - genetic code expansion
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-251035
SN  - 1663-3563
VL  - 13
ER  -