Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

Na+ pump alpha 2-subunit expression modulates Ca2+ signaling.

Vera A Golovina1, Hong Song, Paul F James

  • 1Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA. vgolovin@umaryland.edu

American Journal of Physiology. Cell Physiology
|October 22, 2002
PubMed
Summary
This summary is machine-generated.

Related Concept Videos

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

<b>Three new species and a newly discovered male of the genus <i>Caryanda</i> (Orthoptera: Acrididae) from Yunnan, China</b>.

Zootaxa·2026
Same author

The relationship between family function and behavioral decision-making in patients with gestational diabetes mellitus: a multiple mediation model and cross-lagged analysis of pregnancy-related anxiety and hope.

Frontiers in medicine·2026
Same author

Effect of different ultrasonic power levels on the structure and functional properties of soybean protein hydrolysates-soybean hull polysaccharide (SPHS-SSPS) complexes.

Food chemistry·2026
Same author

Ultrasound Slice-to-Volume Registration via Artifact-Suppressed Ultra-Feature Learning.

IEEE journal of biomedical and health informatics·2026
Same author

Three-dimensional Liver Respiratory Motion Tracking in Ultrasound Images via Vascular Structural Projection Optimization and Multi-path Constrained Estimation.

Ultrasound in medicine & biology·2026
Same author

Robot-Assisted Osteotomy and Reconstruction with AR Guidance in Maxillofacial Reconstructive Surgery.

Cyborg and bionic systems (Washington, D.C.)·2026
Same journal

Skeletal muscle biomass as an underappreciated fate of glucose.

American journal of physiology. Cell physiology·2026
Same journal

Proteomic profile of urinary extracellular vesicles from rats with lithium-induced nephrogenic diabetes insipidus.

American journal of physiology. Cell physiology·2026
Same journal

A non-hydrolyzable candesartan cilexetil analog reveals synergistic activation as a tractable mechanism for TMEM175 modulation.

American journal of physiology. Cell physiology·2026
Same journal

Mitochondrial Calcium Transport in Amino Acid Metabolism: From nutritional responses to metabolic regulation.

American journal of physiology. Cell physiology·2026
Same journal

N-linked glycosylation regulates SNAT2 trafficking and stability in pancreatic ductal adenocarcinoma cells.

American journal of physiology. Cell physiology·2026
Same journal

Oxaloacetate Inhibition of Succinate Dehydrogenase: Mechanism and Physiological Implications.

American journal of physiology. Cell physiology·2026
See all related articles

Reduced alpha(2) sodium pumps amplify calcium signaling in astrocytes by increasing local sodium and calcium levels near the endoplasmic reticulum. This occurs without significantly altering overall cellular sodium concentrations.

Area of Science:

  • Neuroscience
  • Cell Biology
  • Biochemistry

Background:

  • Astrocytes play crucial roles in brain function, including regulating neuronal activity through calcium (Ca2+) signaling.
  • The sodium-potassium pump (Na+/K+-ATPase) is vital for maintaining cellular ion gradients, with different alpha-subunit isoforms potentially having distinct roles.
  • The alpha(2)-subunit of the Na+ pump is known to be localized in specific cellular microdomains.

Purpose of the Study:

  • To investigate the specific role of the Na+ pump alpha(2)-subunit in astrocytic Ca2+ signaling.
  • To determine how alterations in alpha(2)-subunit expression affect intracellular sodium ([Na+]cyt) and Ca2+ ([Ca2+]cyt) levels.
  • To elucidate the impact of alpha(2)-subunit deficiency on Ca2+ responses mediated by the endoplasmic reticulum (ER).

Main Methods:

Related Experiment Videos

  • Primary astrocyte cultures were established from wild-type, heterozygote (Het), and knockout (KO) mice lacking the alpha(2) gene.
  • Na+ pump alpha-subunit expression was quantified using immunoblotting.
  • Intracellular [Na+]cyt and [Ca2+]cyt were measured using fluorescent indicators (SBFI and fura 2) and digital imaging.
  • Ca2+ signaling was assessed by measuring responses to cyclopiazonic acid (CPA) in the presence and absence of extracellular Ca2+.

Main Results:

  • Astrocytes express both alpha(1) and alpha(2) Na+ pump subunits, with alpha(2) comprising approximately 20% of the total.
  • KO and Het astrocytes showed no or reduced alpha(2) expression, respectively, while alpha(1) expression remained normal.
  • Resting [Na+]cyt was significantly elevated only in KO astrocytes, but ouabain (an alpha(2)-specific inhibitor) normalized [Na+]cyt across all groups at a higher level.
  • Resting [Ca2+]cyt was elevated in both Het and KO astrocytes compared to WT.
  • Ca2+ release and subsequent reuptuptake responses to CPA were augmented in Het and KO cells, indicating enhanced ER Ca2+ handling and store-operated Ca2+ entry.

Conclusions:

  • The alpha(2) Na+ pump isoform plays a critical role in regulating local cytosolic Na+ and Ca2+ concentrations within plasma membrane microdomains adjacent to the ER.
  • Reduced alpha(2) Na+ pump activity amplifies Ca2+ signaling by enhancing Na+/Ca2+ exchange, leading to augmented ER Ca2+ stores and increased Ca2+ influx.
  • These findings highlight a specific mechanism by which the alpha(2) Na+ pump modulates astrocytic Ca2+ signaling without substantially altering bulk cytosolic Na+ levels.