Rapid, voltage-dependent potentiation of skeletal muscle L-type calcium channels requires phosphorylation by cAMP-dependent protein kinase (PKA) anchored via an A kinase anchoring protein (AKAP). Here we report the isolation, primary sequence determination, and functional characterization of AKAP15, a lipid-anchored protein of 81 amino acid residues with a single amphipathic helix that binds PKA. AKAP15 colocalizes with L-type calcium channels in transverse tubules and is associated with L-type calcium channels in transfected cells. A peptide fragment of AKAP15 encompassing the RII-binding domain blocks voltage-dependent potentiation. These results indicate that AKAP15 targets PKA to the calcium channel and plays a critical role in voltage-dependent potentiation and regulation of skeletal muscle contraction. The expression of AKAP15 in the brain and heart suggests that it may mediate rapid PKA regulation of L-type calcium channels in neurons and cardiac myocytes.
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http://dx.doi.org/10.1016/s0896-6273(00)80482-1 | DOI Listing |
Cell Mol Life Sci
January 2025
Univ. Lille, CNRS, UMR 8576 - UGSF - Unité de Glycobiologie Structurale Et Fonctionnelle, 59000, Lille, France.
Glycans are known to be fundamental for many cellular and physiological functions. Congenital disorders of glycosylation (CDG) currently encompassing over 160 subtypes, are characterized by glycan synthesis and/or processing defects. Despite the increasing number of CDG patients, therapeutic options remain very limited as our knowledge on glycan synthesis is fragmented.
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December 2024
Department of Physiology, University of Kentucky, Lexington, KY, United States.
Auditory hair cells form precise and sensitive staircase-like actin protrusions known as stereocilia. These specialized microvilli detect deflections induced by sound through the activation of mechano-electrical transduction (MET) channels located at their tips. At rest, a small MET channel current results in a constant calcium influx which regulates the morphology of the actin cytoskeleton in the shorter 'transducing' stereocilia.
View Article and Find Full Text PDFAdv Med Sci
January 2025
Department of Histology and Embryology, Faculty of Medicine, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, Toruń, Poland; Faculty of Medicine, Collegium Medicum, Mazovian Academy in Płock, Płock, Poland.
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View Article and Find Full Text PDFMicroPubl Biol
December 2024
Biology, University of Kentucky, Lexington, Kentucky, United States.
GV-58 is known to increase the opening time of the mammalian P-type calcium channel in presynaptic motor nerve terminals. GV-58 is suggested as a therapeutic agent for dampening the symptoms of amyotrophic lateral sclerosis. To further understand the mechanisms of GV-58 actions, the and crayfish neuromuscular junctions were used as models.
View Article and Find Full Text PDFBiomech Model Mechanobiol
January 2025
CNR Istituto Officina Dei Materiali, Area Science Park Basovizza, S.S. 14, Km 163,5, 34149, Trieste, Italy.
The organization and dynamics of the spectrin-actin membrane cytoskeleton play a crucial role in determining the mechanical properties of red blood cells (RBC). RBC are subjected to various forces that induce deformation during blood microcirculation. Such forces also regulate membrane tension, leading to Piezo1 channel activation, which is functionally linked to RBC dehydration through calcium influx and subsequent activation of Gardos channels, ultimately resulting in variations in RBC volume.
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