The Rad, Rem, Rem2, and Gem/Kir (RGK) sub-family of small GTP-binding proteins are crucial in regulating high voltage-activated (HVA) calcium channels. RGK proteins inhibit calcium current by either promoting endocytosis or reducing channel activity. They all can associate directly with Ca channel β subunit (Caβ), and the binding between Caα1/Caβ appears essential for the endocytic promotion of Ca1.X, Ca2.1, and Ca2.2 channels. In this study, we investigated the inhibition of Ca2.3 channels by RGK proteins in the absence of Caβ. To this end, Xenopus laevis oocytes expressing Ca2.3 channels devoid of auxiliary subunit were injected with purified Gem and Rem and found that only Gem had an effect. Ca currents and charge movements were reduced by injection of Gem, pointing to a reduction in the number of channels in the plasma membrane. Since this reduction was ablated by co-expression of the dominant-negative mutant of dynamin K44A, enhanced endocytosis appears to mediate this reduction in the number of channels. Thus, Gem inhibition of Ca2.3 channels would be the only example of a Caβ independent promotion of dynamin-dependent endocytosis.
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http://dx.doi.org/10.1016/j.bbrc.2021.11.052 | DOI Listing |
Brain Imaging Behav
October 2024
NeuroTRACT International Association, Tehran, Iran.
Background: Recent studies have suggested that the hippocampus (HC) is involved in cognitive and behavioral functions beyond memory. We aimed to investigate how the volume of each subfield of the HC is associated with distinct patterns of coping strategies, emotion regulation, and impulsivity in a healthy population.
Methods: We studied a total of 218 healthy subjects using the Leipzig mind-brain-body dataset.
Cell Mol Neurobiol
April 2023
Department of Physiology, Nanjing Medical University, Nanjing, People's Republic of China.
The blockage of transient receptor potential vanilloid 4 (TRPV4) inhibits inflammation and reduces hippocampal neuronal injury in a pilocarpine-induced mouse model of temporal lobe epilepsy. However, the underlying mechanisms remain largely unclear. NF-κB signaling pathway is responsible for the inflammation and neuronal injury during epilepsy.
View Article and Find Full Text PDFCell Mol Biol (Noisy-le-grand)
December 2018
Department of Acupuncture and Moxibustion, First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, China.
To investigate the expression of miR-22 in the hippocampus of amyloid β (1-42)-induced alzheimic rats, and to assess the underlying mechanism. A total of 60 male Sprague Dawley rats weighing between 274.65 and 293.
View Article and Find Full Text PDFNeuroscience
September 2018
Department of Physiology, Monash University, Melbourne, VIC, Australia. Electronic address:
Changes in inhibition following traumatic brain injury (TBI) appear to be one of the major factors that contribute to excitation:inhibition imbalance. Neuron pathology, interneurons in particular evolves from minutes to weeks post injury and follows a complex time course. Previously, we showed that in the long-term in diffuse TBI (dTBI), there was select reduction of specific dendrite-targeting neurons in sensory cortex and hippocampus while in motor cortex there was up-regulation of specific dendrite-targeting neurons.
View Article and Find Full Text PDFJ Comp Neurol
December 2016
Department of Physiology, Monash University, Melbourne, VIC, Australia.
Long-term diffuse traumatic brain injury (dTBI) causes neuronal hyperexcitation in supragranular layers in sensory cortex, likely through reduced inhibition. Other forms of TBI affect inhibitory interneurons in subcortical areas but it is unknown if this occurs in cortex, or in any brain area in dTBI. We investigated dTBI effects on inhibitory neurons and astrocytes in somatosensory and motor cortex, and hippocampus, 8 weeks post-TBI.
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