Two mutants of Paramecium tetraurelia with greatly reduced Ca2+-dependent K+ currents have been isolated and genetically analyzed. These mutants, designated pantophobiac, give much stronger behavioral responses to all stimuli than do wild-type cells. Under voltage clamp, the Ca2+-dependent K+ current is almost completely eliminated in these mutants, whereas the Ca2+ current is normal. The two mutants, pntA and pntB, are recessive and unlinked to each other. pntA is not allelic to several other ion-channel mutants of P. tetraurelia. The microinjection of a high-speed supernatant fraction of wild-type cytoplasm into either pantophobiac mutant caused a temporary restoration to the wild-type phenotype.
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http://dx.doi.org/10.1093/genetics/111.3.433 | DOI Listing |
J Gen Physiol
March 2025
Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, USA.
Voltage-gated Ca2+ channels (VGCCs) are highly expressed throughout numerous biological systems and play critical roles in synaptic transmission, cardiac excitation, and muscle contraction. To perform these various functions, VGCCs are highly regulated. Inactivation comprises a critical mechanism controlling the entry of Ca2+ through these channels and constitutes an important means to regulate cellular excitability, shape action potentials, control intracellular Ca2+ levels, and contribute to long-term potentiation and depression.
View Article and Find Full Text PDFInvest Ophthalmol Vis Sci
January 2025
School of Graduate, Dalian Medical University, Dalian City, China.
Purpose: To investigate the effect of Ca2+/calmodulin-dependent protein kinase II (CAMKII) δ subtypes (CAMK2D) on sodium iodate (NaIO3)-induced retinal degeneration in mice.
Methods: Bioinformatics analysis and Western blot experiments were used to screen the significantly differentially expressed genes in age-related macular degeneration (AMD) disease. CAMK2D knockdown and overexpression models were constructed by lentivirus (LV) infection of adult retinal pigment epithelial cell line-19 (ARPE-19) cells in vitro.
Int J Mol Sci
January 2025
Division of Cardiology, Department of Internal Medicine, Chang Gung Memorial Hospital, Taoyuan Branch, Taoyuan 33304, Taiwan.
The electrophysiological mechanisms underlying melatonin's actions and the electrophysiological consequences of superimposed therapeutic hypothermia (TH) in preventing cardiac ischemia-reperfusion (IR) injury-induced arrhythmias remain largely unknown. This study aimed to unveil these issues using acute IR-injured hearts. Rabbits were divided into heart failure (HF), HF+melatonin, control, and control+melatonin groups.
View Article and Find Full Text PDFChemMedChem
January 2025
University of Michigan Michigan Medicine, Internal Medicine, 2800 Plymouth Rd, NCRC 26-220S, 48109, Ann Arbor, UNITED STATES OF AMERICA.
A key molecular dysfunction in heart failure is the reduced activity of the cardiac sarcoplasmic reticulum Ca2+-ATPase (SERCA2a) in cardiac muscle cells. Reactivating SERCA2a improves cardiac function in heart failure models, making it a validated target and an attractive therapeutic approach for heart failure therapy. However, finding small-molecule SERCA2a activators is challenging.
View Article and Find Full Text PDFBehav Brain Res
January 2025
Department of Pharmaceutical Sciences, College of Pharmacy, South Dakota State University, Brookings, SD 57007, USA. Electronic address:
The astroglial glutamate transporter in the hippocampus and anterior cingulate cortex (ACC) is critically involved in chronic pain-induced cognitive and psychiatric abnormalities. We have previously reported that LDN-212320, a glutamate transporter-1 (GLT-1) activator, attenuates complete Freund's adjuvant (CFA)-induced acute and chronic nociceptive pain. However, the cellular and molecular mechanisms underlying GLT-1 modulation in the hippocampus and ACC during chronic pain-induced cognitive deficit-like and anxiety-like behaviors remain unknown.
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