Voltage-dependent potentiation of skeletal muscle L-type calcium channels requires phosphorylation by cAMP-dependent protein kinase (PKA) that is localized by binding to a cAMP-dependent protein kinase-anchoring protein (AKAP). L-type calcium channels purified from rabbit skeletal muscle contain an endogenous co-purifying protein kinase activity that phosphorylates the alpha1 and beta subunits of the channel. The co-purifying kinase also phosphorylates a known PKA peptide substrate, is stimulated by cAMP, and is inhibited by PKA inhibitor peptide-(5-24), indicating that it is PKA. PKA activity co-immunoprecipitates with the calcium channel, suggesting that the channel and the kinase are physically associated. Using biotinylated type II regulatory subunit of PKA (RII) as a probe, we have identified a 15-kDa RII-binding protein in purified calcium channel preparations, which we have designated AKAP-15. Anti-peptide antibodies directed against the alpha1 subunit of the calcium channel co-immunoprecipitate AKAP-15. Together, these findings demonstrate a physical link between PKA and the calcium channel and suggest that AKAP-15 may mediate their interaction.
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http://dx.doi.org/10.1074/jbc.272.10.6297 | DOI Listing |
Front Pharmacol
January 2025
Department of Cardiovascular Center, First Affiliated Hospital of Huzhou University, Huzhou, China.
The emergence of targeted anti-tumor drugs has significantly prolonged the lifespan and improved the prognosis of cancer patients. Among these drugs, vascular endothelial growth factor (VEGF) inhibitors, particularly novel small molecule tyrosine kinase inhibitors (TKIs), are extensively employed as VEGF inhibitors; however, they are also associated with a higher incidence of complications, with hypertension being the most prevalent cardiovascular toxic side effect. Currently, it is widely accepted that TKIs-induced hypertension involves multiple mechanisms including dysregulation of the endothelin (ET) axis, reduced bioavailability of nitric oxide (NO), imbalance in NO-ROS equilibrium system, vascular rarefaction, and activation of epithelial sodium calcium channels; nevertheless, excessive activation of ET system appears to be predominantly responsible for this condition.
View Article and Find Full Text PDFStem Cell Res Ther
January 2025
Department of Cell Biology and Histology, University of the Basque Country UPV/EHU, Leioa, Bizkaia, 48940, Spain.
Background And Aim: Human dental pulp stem cells (hDPSCs) constitute a promising alternative for central nervous system (CNS) cell therapy. Unlike other human stem cells, hDPSCs can be differentiated, without genetic modification, to neural cells that secrete neuroprotective factors. However, a better understanding of their real capacity to give rise to functional neurons and integrate into synaptic networks is still needed.
View Article and Find Full Text PDFNeurotherapeutics
January 2025
Departamento de Medicina Intensiva, Facultad de Medicina, Pontificia Universidad Católica de Chile, Chile. Electronic address:
Acute brain injuries (ABIs) encompass a broad spectrum of primary injuries such as ischemia, hypoxia, trauma, and hemorrhage that converge into secondary injury where some mechanisms show common determinants. In this regard, astroglial connexin and pannexin channels have been shown to play an important role. These channels are transmembrane proteins sharing similar topology and form gateways between adjacent cells named gap junctions (GJs) and pores into unopposed membranes named hemichannels (HCs).
View Article and Find Full Text PDFRedox Biol
January 2025
Laboratory for Research in Functional Nutrition, Instituto de Nutrición y Tecnología de los Alimentos, Universidad de Chile, Av. El Líbano 5524, Macul, Santiago, 7830490, Chile. Electronic address:
Caffeic acid phenethyl ester (CAPE) is a hydrophobic phytochemical typically found in propolis that acts as an antioxidant, anti-inflammatory and cardiovascular protector, among several other properties. However, the molecular entity responsible for recognising CAPE is unknown, and whether that molecular interaction is involved in developing an antioxidant response in the target cells remains an unanswered question. Herein, we hypothesized that a subfamily of TRP ion channels works as the molecular entity that recognizes CAPE at the plasma membrane and allows a fast shift in the antioxidant capacity of intact endothelial cells (EC).
View Article and Find Full Text PDFJ Venom Anim Toxins Incl Trop Dis
January 2025
School of Health Santa Casa BH, Belo Horizonte, MG, Brazil.
Background: This study examines the impact of Phα1β, a spider peptide derived from the venom of , on the Kv11.1 potassium channel in HEK293 cells transfected with the human ERG potassium channel. Phα1β inhibits high-voltage calcium channels and acts as an antagonist of the TRPA1 receptor, both of which play crucial roles in pain transduction pathways.
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