Related Experiment Video

Updated: Jun 4, 2026

Isolation of Primary Patient-specific Aortic Smooth Muscle Cells and Semiquantitative Real-time Contraction Measurements In Vitro
08:28

Isolation of Primary Patient-specific Aortic Smooth Muscle Cells and Semiquantitative Real-time Contraction Measurements In Vitro

Published on: February 15, 2022

A phospholipase Cγ1-activated pathway regulates transcription in human vascular smooth muscle cells

Irene Hunter1, Keith S Mascall, Joe W Ramos

  • 1School of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, UK.

Cardiovascular Research
|February 3, 2011
PubMed
Abstract

Insights

Phospholipase C (PLC)γ1 activation phosphorylates protein enriched in astrocytes-15 (PEA-15), regulating extracellular signal-regulated kinase 1/2 (ERK1/2) nuclear translocation and smooth muscle gene expression.

Area of Science:

  • Vascular smooth muscle cell biology
  • Molecular signaling pathways
  • Gene regulation

Background:

  • Growth factors regulate vascular smooth muscle (VSM) cell proliferation by repressing SM cell marker genes.
  • Extracellular signal-regulated kinase 1/2 (ERK1/2) nuclear translocation and Elk-1 activation mediate this repression.
  • The specific mechanisms controlling ERK1/2 nuclear translocation in VSM cells remain unclear.

Purpose of the Study:

  • To investigate the molecular mechanisms governing growth factor-induced nuclear translocation of ERK1/2.
  • To elucidate the role of signaling intermediates in regulating gene expression and VSM cell proliferation.
  • To identify key regulators of ERK1/2 nuclear entry in response to platelet-derived growth factor (PDGF).

Main Methods:

  • Utilized cultured human VSM cells.
  • Employed siRNA to deplete protein enriched in astrocytes-15 (PEA-15).
  • Assessed ERK1/2 and Elk-1 phosphorylation, gene expression (SM α-actin), and cell proliferation.
  • Investigated protein-protein interactions and utilized overexpression systems for PEA-15 and its mutants.

Main Results:

  • Phospholipase C (PLC)γ1 activation was essential for PDGF-induced ERK1/2 nuclear translocation, Elk-1 phosphorylation, and SM α-actin repression.
  • PDGF induced PEA-15 phosphorylation, which was dependent on PLCγ1 activation.
  • PEA-15 siRNA treatment increased ERK1/2 nuclear entry, decreased SM α-actin expression, and enhanced VSM cell proliferation.
  • PEA-15 overexpression promoted ERK1/2 cytoplasmic localization, while a non-phosphorylatable PEA-15 mutant inhibited PDGF-induced ERK1/2 nuclear translocation.

Conclusions:

  • PEA-15 phosphorylation, mediated by PLCγ1, is a critical step for PDGF-induced ERK1/2 nuclear translocation.
  • This pathway represents a key regulatory mechanism controlling Elk-1-dependent transcription.
  • The findings highlight a novel mechanism for phenotypic control in VSM cells, impacting SM cell marker expression.

More Related Videos

Visualization and Quantification of TGFβ/BMP/SMAD Signaling under Different Fluid Shear Stress Conditions using Proximity-Ligation-Assay11:38

Visualization and Quantification of TGFβ/BMP/SMAD Signaling under Different Fluid Shear Stress Conditions using Proximity-Ligation-Assay

Published on: September 14, 2021

Isolation of Intrapulmonary Artery and Smooth Muscle Cells to Investigate Vascular Responses07:56

Isolation of Intrapulmonary Artery and Smooth Muscle Cells to Investigate Vascular Responses

Published on: June 8, 2022

Related Concept Videos

TGF - β Signaling Pathway01:16

TGF - β Signaling Pathway

The TGF-β signaling pathway regulates cell growth, differentiation, adhesion, motility, and development. TGF-β ligands that induce TGF-β signaling are synthesized in their latent form. Several proteases or cell surface receptors such as integrins act upon the latent form, releasing the active ligand. There are three types of mammalian TGF-βs: (TGF-β1, TGF-β2, and TGF-β3) that bind as homodimers or heterodimers to TGF-β receptors. The TGF-β receptors are of three kinds RI, RII, and RIII. The RI...
IP3/DAG Signaling Pathway01:11

IP3/DAG Signaling Pathway

Membrane lipids such as phosphatidylinositol (PI) are precursors for several membrane-bound and soluble second messengers. Specific kinases phosphorylate PI and produce phosphorylated inositol phospholipids. One such inositol phospholipids are the  phosphatidylinositol-4,5 bisphosphate [PI(4,5)P2], present in the inner half of the lipid bilayer. Upon ligand binding, GPCR stimulates Gq proteins to turn on phospholipase Cꞵ. Activated phospholipase Cꞵ cleaves PI(4,5)P2 and produces two-second...
Nitric Oxide Signaling Pathway01:28

Nitric Oxide Signaling Pathway

Nitric oxide (NO), an inorganic gas, acts as a potent second messenger in most animal and plant tissues. NO diffuses out of the cells that produce it and enters the neighboring cells to generate a downstream response. NO synthase (NOS) catalyzes NO production by the deamination of the amino acid arginine. There are three isoforms of NOS. Endothelial cells have endothelial NOS (eNOS), nerve and muscle cells have neuronal NOS (nNOS), and macrophages produce inducible NOS (iNOS) upon exposure to...
Amplifying Signals via Second Messengers01:15

Amplifying Signals via Second Messengers

Many receptor binding ligands are hydrophilic; they do not cross the cell membrane but bind to cell-surface receptors. Thus, their message must be relayed by second messengers present in the cell cytoplasm. There are several second messenger pathways, each with its own way of relaying information. For example, the G protein-coupled receptors can activate both phosphoinositol and cyclic AMP (cAMP) second messenger pathways. The phosphoinositol pathway is active when the receptor induces...
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,...
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...