Related Experiment Video

Updated: Sep 3, 2026

A Functional Assay for Gap Junctional Examination; Electroporation of Adherent Cells on Indium-Tin Oxide
11:02

A Functional Assay for Gap Junctional Examination; Electroporation of Adherent Cells on Indium-Tin Oxide

Published on: October 18, 2014

Growth factors induce phosphorylation of the Na+/H+ antiporter, glycoprotein of 110 kD

C Sardet1, L Counillon, A Franchi

  • 1Centre de Biochimie-CNRS, Nice, France.

Science (New York, N.Y.)
|February 9, 1990
PubMed

Insights

The study identified the Na+/H+ antiporter as a phosphorylated glycoprotein. Its phosphorylation increases with mitogenic stimulation, suggesting a role in regulating intracellular pH.

Area of Science:

  • Cellular Biology
  • Biochemistry
  • Molecular Biology

Background:

  • The Na+/H+ antiporter regulates intracellular pH in all cells.
  • Its activity is rapidly altered by mitogenic and oncogene activation, but the mechanism is unknown.

Purpose of the Study:

  • To investigate the molecular mechanism of Na+/H+ antiporter activation.

Main Methods:

  • Expressed a Na+/H+ antiporter cDNA fragment in E. coli as a fusion protein.
  • Developed a specific antibody against the fusion protein.
  • Utilized the antibody to detect and characterize the antiporter in mammalian cells.

Main Results:

  • Identified the Na+/H+ antiporter as a 110-kilodalton glycoprotein.
  • Demonstrated that the antiporter is phosphorylated in growing cells.
  • Showed that mitogenic activation stimulates antiporter phosphorylation, correlating with increased intracellular pH.

Conclusions:

  • The Na+/H+ antiporter is a glycoprotein whose phosphorylation is modulated by mitogenic signals.
  • This phosphorylation likely plays a role in the rapid changes in antiporter activity observed upon stimulation.

More Related Videos

Functional Characterization of Na+/H+ Exchangers of Intracellular Compartments Using Proton-killing Selection to Express Them at the Plasma Membrane07:38

Functional Characterization of Na+/H+ Exchangers of Intracellular Compartments Using Proton-killing Selection to Express Them at the Plasma Membrane

Published on: March 30, 2015

Study of the Functions and Activities of Neuronal K-Cl Co-Transporter KCC2 Using Western Blotting10:08

Study of the Functions and Activities of Neuronal K-Cl Co-Transporter KCC2 Using Western Blotting

Published on: December 9, 2022

Related Concept Videos

Primary Active Transport01:47

Primary Active Transport

In contrast to passive transport, active transport involves a substance being moved through membranes in a direction against its concentration or electrochemical gradient. There are two types of active transport: primary active transport and secondary active transport. Primary active transport utilizes chemical energy from ATP to drive protein pumps that are embedded in the cell membrane. With energy from ATP, the pumps transport ions against their electrochemical gradients—a direction they...
Secondary Active Transport01:55

Secondary Active Transport

One example of how cells use the energy contained in electrochemical gradients is demonstrated by glucose transport into cells. The ion vital to this process is sodium (Na+), which is typically present in higher concentrations extracellularly than in the cytosol. Such a concentration difference is due, in part, to the action of an enzyme “pump” embedded in the cellular membrane that actively expels Na+ from a cell. Importantly, as this pump contributes to the high concentration of...
Primary Active Transport01:29

Primary Active Transport

In contrast to passive transport, active transport involves a substance being moved through membranes in a direction against its concentration or electrochemical gradient. There are two types of active transport: primary active transport and secondary active transport. Primary active transport utilizes chemical energy from ATP to drive protein pumps embedded in the cell membrane. With energy from ATP, the pumps transport ions against their electrochemical gradients—a direction they would not...
Secondary Active Transport01:32

Secondary Active Transport

One example of how cells use the energy contained in electrochemical gradients is demonstrated by glucose transport into cells. The ion vital to this process is sodium (Na+), which is typically present in higher concentrations extracellularly than in the cytosol. Such a concentration difference is due, in part, to the action of an enzyme "pump" embedded in the cellular membrane that actively expels Na+ from a cell. Importantly, as this pump contributes to the high concentration of...
Amplifying Signals via Enzymatic Cascade01:22

Amplifying Signals via Enzymatic Cascade

When a ligand binds to a cell-surface receptor, the receptor's intracellular domain changes shape, which may either activate its enzyme function or allow its binding to other molecules. The initial signal is amplified by most signal transduction pathways. This means that a single ligand molecule can activate multiple molecules of a downstream target. Proteins that relay a signal are most commonly phosphorylated at one or more sites, activating or inactivating the protein. Kinases catalyze the...
cAMP-dependent Protein Kinase Pathways01:25

cAMP-dependent Protein Kinase Pathways

Cyclic Adenosine Monophosphate (cAMP) is an essential second messenger that activates protein kinase A (PKA) and regulates various biological processes. A single epinephrine molecule binds to GPCR and activates several heterotrimeric G proteins, each stimulating multiple adenylyl cyclase, amplifying the signal, and synthesizing large numbers of cAMP molecules. Small changes in cAMP concentration affect PKA activity. The binding of four cAMP molecules induces a conformational change in PKA,...