TY  - JOUR
A1  - Maiellaro, Isabella
A1  - Lohse, Martin J.
A1  - Kitte, Robert J.
A1  - Calebiro, Davide
T1  - cAMP Signals in Drosophila Motor Neurons Are Confined to Single Synaptic Boutons
JF  - Cell Reports
N2  - The second messenger cyclic AMP (cAMP) plays an important role in synaptic plasticity. Although there is evidence for local control of synaptic transmission and plasticity, it is less clear whether a similar spatial confinement of cAMP signaling exists. Here, we suggest a possible biophysical basis for the site-specific regulation of synaptic plasticity by cAMP, a highly diffusible small molecule that transforms the physiology of synapses in a local and specific manner. By exploiting the octopaminergic system of Drosophila, which mediates structural synaptic plasticity via a cAMP-dependent pathway, we demonstrate the existence of local cAMP signaling compartments of micrometer dimensions within single motor neurons. In addition, we provide evidence that heterogeneous octopamine receptor localization, coupled with local differences in phosphodiesterase activity, underlies the observed differences in cAMP signaling in the axon, cell body, and boutons.
KW  - cAMP
KW  - synaptic plasticity
KW  - PDE
KW  - octopamine
KW  - FRET
KW  - active zone
KW  - dunce
KW  - GPCR
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-162324
VL  - 17
IS  - 5
ER  - 
TY  - JOUR
A1  - Gmach, Philipp
A1  - Bathe-Peters, Marc
A1  - Telugu, Narasimha
A1  - Miller, Duncan C.
A1  - Annibale, Paolo
T1  - Fluorescence spectroscopy of low-level endogenous β-adrenergic receptor expression at the plasma membrane of differentiating human iPSC-derived cardiomyocytes
JF  - International Journal of Molecular Sciences
N2  - The potential of human-induced pluripotent stem cells (hiPSCs) to be differentiated into cardiomyocytes (CMs) mimicking adult CMs functional morphology, marker genes and signaling characteristics has been investigated since over a decade. The evolution of the membrane localization of CM-specific G protein-coupled receptors throughout differentiation has received, however, only limited attention to date. We employ here advanced fluorescent spectroscopy, namely linescan Fluorescence Correlation Spectroscopy (FCS), to observe how the plasma membrane abundance of the β\(_1\)- and β\(_2\)-adrenergic receptors (β\(_{1/2}\)-ARs), labelled using a bright and photostable fluorescent antagonist, evolves during the long-term monolayer culture of hiPSC-derived CMs. We compare it to the kinetics of observed mRNA levels in wildtype (WT) hiPSCs and in two CRISPR/Cas9 knock-in clones. We conduct these observations against the backdrop of our recent report of cell-to-cell expression variability, as well as of the subcellular localization heterogeneity of β-ARs in adult CMs.
KW  - GPCR
KW  - β-adrenergic receptors
KW  - hiPSC-CM
KW  - cardiomyocyte
KW  - fluorescence correlation spectroscopy
KW  - FCS
KW  - fluorescence
KW  - CRISPR/Cas9
KW  - differentiation
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-288277
SN  - 1422-0067
VL  - 23
IS  - 18
ER  -