Site-specific modification of AAV vector particles with biophysical probes and targeting ligands using biotin ligase.
AuthorsStachler MD, Chen I, Ting AY, Bartlett JS,
JournalMol Ther
PubMed ID18560418
'We have developed a highly specific and robust new method for labeling adeno-associated virus (AAV) vector particles with either biophysical probes or targeting ligands. Our approach uses the Escherichia coli enzyme biotin ligase (BirA), which ligates biotin to a 15-amino-acid biotin acceptor peptide (BAP) in a sequence-specific manner. In this ... More
Counting contacts between neurons in 3D in confocal laser scanning images.
'Study of neuronal networks requires an inventory of the neurons, knowledge of fiber in- and output, and qualitative and quantitative data on the intrinsic connectivity. For this purpose we combined in rat hippocampus fluorescence neuroanatomical tracing and intracellular fluorochrome injection of neurons. Multichannel confocal laser scanning microscopy was followed by ... More
Signal sequence-independent membrane targeting of ribosomes containing short nascent peptides within the exit tunnel.
'Ribosomes synthesizing inner membrane proteins in Escherichia coli are targeted to the translocon in the plasma membrane by the signal recognition particle (SRP) and the SRP receptor, FtsY. Here we show using a purified system that membrane targeting does not require an exposed signal-anchor sequence, as SRP-dependent targeting takes place ... More
A novel role for MNTB neuron dendrites in regulating action potential amplitude and cell excitability during repetitive firing.
AuthorsLeão RN, Leão RM, da Costa LF, Rock Levinson S, Walmsley B,
JournalEur J Neurosci
PubMed ID18598256
'Principal cells of the medial nucleus of the trapezoid body (MNTB) are simple round neurons that receive a large excitatory synapse (the calyx of Held) and many small inhibitory synapses on the soma. Strangely, these neurons also possess one or two short tufted dendrites, whose function is unknown. Here we ... More
Mechanisms of quenching of Alexa fluorophores by natural amino acids.
Quenching of fluorophores by the same proteins that they covalently label is a phenomenon that is neither well-known nor well-characterized. It is often assumed that fluorophores are unperturbed by their target proteins. However, it has been observed that attached fluorophores can be quenched by contact with amino acids within the ... More
Subpopulation-specific patterns of intrinsic connectivity in mouse superficial dorsal horn as revealed by laser scanning photostimulation.
AuthorsKosugi M, Kato G, Lukashov S, Pendse G, Puskar Z, Kozsurek M, Strassman AM,
JournalJ Physiol
PubMed ID23297304
The primary goal of this study was to map the transverse distribution of local excitatory and inhibitory synaptic inputs to mouse lamina I spinal dorsal horn neurons, using laser scanning photostimulation. A sample of lamina II neurons was also studied for comparison. Lamina I neurons received excitatory synaptic input from ... More
Initiation and propagation of action potentials in gonadotropin-releasing hormone neuron dendrites.
AuthorsIremonger KJ, Herbison AE,
JournalJ Neurosci
PubMed ID22219278
Gonadotropin-releasing hormone (GnRH) neurons are the final output neurons in a complex neuronal network that regulates fertility. The morphology of GnRH neuron dendrites is very different to other central neurons in that they are very long, thin, and unbranched. To study the function of these dendrites, we have used Na(+) ... More
Trigger factor binds to ribosome-signal-recognition particle (SRP) complexes and is excluded by binding of the SRP receptor.
AuthorsBuskiewicz I, Deuerling E, Gu SQ, Jöckel J, Rodnina MV, Bukau B, Wintermeyer W,
JournalProc Natl Acad Sci U S A
PubMed ID15148364
Trigger factor (TF) and signal recognition particle (SRP) bind to the bacterial ribosome and are both crosslinked to protein L23 at the peptide exit, where they interact with emerging nascent peptide chains. It is unclear whether TF and SRP exclude one another from their ribosomal binding site(s). Here we show ... More
Conformations of the signal recognition particle protein Ffh from Escherichia coli as determined by FRET.
AuthorsBuskiewicz I, Peske F, Wieden HJ, Gryczynski I, Rodnina MV, Wintermeyer W,
JournalJ Mol Biol
PubMed ID16005894
The signal recognition particle (SRP) initiates the co-translational targeting of proteins to the plasma membrane in bacteria by binding to the N-terminal signal sequence emerging from the translating ribosome. SRP in Escherichia coli is composed of one protein, Ffh, and 4.5S RNA. In the present work, we probe the structure ... More
Dynamic regulation of spine-dendrite coupling in cultured hippocampal neurons.
AuthorsKorkotian E, Holcman D, Segal M
JournalEur J Neurosci
PubMed ID15548208
We investigated the role of dendritic spine morphology in spine-dendrite calcium communication using novel experimental and theoretical approaches. A transient rise in [Ca2+]i was produced in individual spine heads of Fluo-4-loaded cultured hippocampal neurons by flash photolysis of caged calcium. Following flash photolysis in the spine head, a delayed [Ca2+]i ... More
Facilitation of L-type Ca2+ channels in dendritic spines by activation of beta2 adrenergic receptors.
AuthorsHoogland TM, Saggau P
JournalJ Neurosci
PubMed ID15456814
We studied the contribution of L-type Ca2+ channels to action potential-evoked Ca2+ influx in dendritic spines of CA1 pyramidal neurons and the modulation of these channels by the beta2 adrenergic receptor. Backpropagating action potentials (bAPs) (three at 50 Hz) were evoked by brief somatic current injections, and Ca2+ transients were ... More