A 20 amino acid synthetic peptide, corresponding to the amino-terminal region of the Shaker B (ShB) K+ channel and responsible for its fast inactivation, can block large conductance Ca(2+)-dependent K+ channels from rat brain and muscle. The ShB inactivation peptide produces two kinetically distinct blocking events in these channels. At lower concentrations, it produces short blocks, and at hig...

Voltage-sensitive K channels speed membrane repolarization, thus narrowing action potential (AP) waveforms. The spike waveform at synaptic terminals strongly influences the kinetics of neurotransmitter release. Because recording APs at synaptic terminals is difficult, however, researchers typically examine EPSPs to identify contributors to presynaptic waveform. For example, mutation of shaker, ...

Shaker genes encode voltage-gated potassium channels (Kv). We have shown previously that genes from Shaker subfamilies Kv1.1, 1.2, 1.4 are expressed in rabbit kidney. Recent functional and molecular evidence indicate that the predominant potassium conductance of the kidney medullary cell line GRB-PAP1 is composed of Shaker-like potassium channels. We now report the molecular cloning and functio...

We studied the structure of the C terminus of the Shaker potassium channel. The 3D structures of the full-length and a C-terminal deletion (Delta C) mutant of Shaker were determined by electron microscopy and single-particle analysis. The difference map between the full-length and the truncated channels clearly shows a compact density, located on the sides of the T1 domain, that corresponds to ...

Jean-Luc Arrègle, EMLYON Business School (editor) Laure Cabantous, Cass Business School (editor) Stewart Clegg, University of Technology, Sydney (editor) Olivier Germain, Université du Québec à Montréal (editor, book reviews) Karim Mignonac, Université de Toulouse 1 (editor) Philippe Monin, EMLYON Business School (editor) Tyrone Pitsis, University of Newcastle (editor) José Pla-Barber, Universi...

Centrally released oxytocin (OT) is believed to attenuate the response of the hypothalamic-pituitary-adrenal (HPA) axis to psychogenic stress. To test this hypothesis, we measured plasma corticosterone concentrations and Fos-immunoreactive protein in the paraventricular nucleus of the hypothalamus (PVN) and limbic brain areas of female wild-type and OT knockout mice that were exposed to a shake...

BACKGROUND Flutter VRP1, Shaker, and Acapella are devices that combine positive expiratory pressure (PEP) and oscillations. OBJECTIVES To compare the mechanical performance of the Flutter VRP1, Shaker, and Acapella devices. METHODS An experimental platform and a ventilator, used a flow generator at 5, 10, 15, 20, 26, and 32 L/min, were employed at angles of -30°, 0°, and +30° to evaluate Fl...

Substitution of the S4 of Shaw into Shaker alters cooperativity in channel activation by slowing a cooperative transition late in the activation pathway. To determine the amino acids responsible for the functional changes in Shaw S4, we created several mutants by substituting amino acids from Shaw S4 into Shaker. The S4 amino acid sequences of Shaker and Shaw S4 differ at 11 positions. Simultan...