Related Experiment Video
Updated: Jul 21, 2026
Electroconvulsive Seizures in Rats and Fractionation of Their Hippocampi to Examine Seizure-induced Changes in Postsynaptic Density Proteins
Published on: August 15, 2017
Estradiol (E2) elicits SRC phosphorylation in the mouse neocortex: the initial event in E2 activation of the MAPK
I S Nethrapalli1, M Singh, X Guan
1Department of Anatomy and Cell Biology, Columbia University College of Physicians and Surgeons, New York, New York 10032, USA.
Abstract:
In neocortical explants, E2 activates various signaling components of the MAPK cascade, including B-Raf and MAPK kinase-dependent ERK, suggesting a possible role in the differentiative actions of E2 in the brain. To further characterize the signaling pathways activated by E2, we determined whether c-Src, a member of the Src family of nonreceptor tyrosine kinases and an important modulator of both the MAPK cascade and neuronal differentiation, may play a role in E2 signaling. The present studies show for the first time in the brain that E2 elicits phosphorylation of c-Src on three functionally critical tyrosine residues (Y220, Y423, and Y534), and that this phosphorylation occurs despite disruption of ER alpha (in ER knockout mice). PP2, a Src family kinase inhibitor, suppressed not only E2-induced phosphorylation of c-Src, but ERK phosphorylation as well, suggesting that c-Src may be an upstream regulator of E2 signaling. E2-induced phosphorylation of c-Src is associated with increased tyrosine phosphorylation of Shc, increased association of Shc with Grb2, and induction of Ras, but not Rap1, activation. Together, these data provide evidence that E2 activates a novel c-Src-dependent signal transduction pathway in the developing brain.
Insights
Estrogen (E2) activates a novel c-Src-dependent pathway in the developing brain, influencing neuronal differentiation. This pathway involves c-Src, Shc, Grb2, and Ras, independent of estrogen receptor alpha.
Area of Science:
- Neuroscience
- Cell Signaling
- Molecular Biology
Background:
- Estrogen (E2) influences brain development and neuronal differentiation.
- The MAPK cascade, including ERK, is implicated in E2's differentiative actions.
- c-Src, a nonreceptor tyrosine kinase, modulates the MAPK cascade and neuronal differentiation.
Purpose of the Study:
- To investigate the role of c-Src in E2-mediated signaling pathways in the developing brain.
- To elucidate the specific signaling components downstream of c-Src activated by E2.
Main Methods:
- Utilized neocortical explants and ER knockout mice.
- Assessed protein phosphorylation using Western blotting.
- Employed a Src family kinase inhibitor (PP2).
- Analyzed protein-protein interactions and small GTPase activation.
Main Results:
- E2 induced phosphorylation of c-Src on critical tyrosine residues (Y220, Y423, Y534) in a manner independent of ER alpha.
- PP2 inhibited E2-induced phosphorylation of both c-Src and ERK.
- E2-activated c-Src signaling led to increased tyrosine phosphorylation of Shc, enhanced Shc-Grb2 association, and Ras activation.
Conclusions:
- E2 activates a novel c-Src-dependent signal transduction pathway in the developing brain.
- c-Src acts as an upstream regulator in E2 signaling, influencing the MAPK cascade.
- This pathway contributes to the differentiative effects of E2 in the brain.
Related Concept Videos
02:38Mitogens and the Cell Cycle
01:07MAPK Signaling Cascades