Related Experiment Video

Updated: Jul 24, 2026

Fibroblast Derived Human Engineered Connective Tissue for Screening Applications
09:50

Fibroblast Derived Human Engineered Connective Tissue for Screening Applications

Published on: August 20, 2021

RhoA/rho-associated kinase mediates fibroblast contractile force generation

H F Yee1, A C Melton, B N Tran

  • 1Department of Medicine, University of California Los Angeles School of Medicine, Los Angeles, California 90095, USA.

Biochemical and Biophysical Research Communications
|February 13, 2001
PubMed

Insights

The rhoA/rho-associated kinase pathway is key for non-muscle cell contraction. Inhibiting this pathway reduces myosin II regulatory light chain phosphorylation and contractile force, confirming its central role.

Area of Science:

  • Cell biology
  • Molecular signaling
  • Biochemistry

Background:

  • Intracellular signals regulating non-muscle cell contractile force are not fully understood.
  • Identifying key signaling pathways is crucial for understanding cell mechanics.

Purpose of the Study:

  • To investigate the role of the rhoA/rho-associated kinase signaling pathway in mediating contractile force generation in non-muscle cells.
  • To test the hypothesis that this pathway is a principal mediator of cellular contraction.

Main Methods:

  • Measurement of myosin II regulatory light chain (MLC) phosphorylation.
  • Direct quantitation of contractile force generation in chicken embryo fibroblasts.
  • Utilizing selective inhibitors for rhoA (C3 transferase) and rho-associated kinase (Y-27632).

Main Results:

  • Inactivation of rhoA inhibited serum-stimulated MLC phosphorylation and contractile force.
  • Y-27632 reduced basal contractile tension and inhibited MLC phosphorylation and force stimulated by serum and endothelin-1.
  • These findings demonstrate the pathway's involvement in both basal and stimulated contraction.

Conclusions:

  • The rhoA/rho-associated kinase signaling pathway is a principal mediator of MLC phosphorylation.
  • This pathway is essential for contractile force generation in non-muscle cells.
  • Provides novel evidence for the molecular mechanisms underlying non-muscle cell contractility.

More Related Videos

Simplified, High-throughput Analysis of Single-cell Contractility using Micropatterned Elastomers14:33

Simplified, High-throughput Analysis of Single-cell Contractility using Micropatterned Elastomers

Published on: April 8, 2022

Optogenetic Inhibition of Rho1-Mediated Actomyosin Contractility Coupled with Measurement of Epithelial Tension in Drosophila Embryos12:35

Optogenetic Inhibition of Rho1-Mediated Actomyosin Contractility Coupled with Measurement of Epithelial Tension in Drosophila Embryos

Published on: April 14, 2023

Related Concept Videos

The Contractile Ring02:15

The Contractile Ring

Contractile rings are composed of microfilaments and are responsible for separating the daughter cells during cytokinesis. Contractile ring assembly proceeds along with other cell cycle events; however, very few mechanistic details are known about the timing and coordination of the contractile rings with the cell cycle.
A small GTPase, RhoA, controls the function and assembly of the contractile ring. RhoA belongs to the Ras superfamily of proteins. The activation of formins by RhoA promotes...
Cell Motility through Blebbing01:16

Cell Motility through Blebbing

Blebs are a type of membrane protrusion formed by the internal hydrostatic pressure of the cytoplasm. Blebs are observed in several cell types, including fibroblasts, immune cells, and single-celled organisms like the amoeba. The primary function of blebs is cell locomotion and apoptosis, but they are also found during necrosis and cell division. The life cycle of a bleb comprises an initiation phase followed by the expansion and retraction phases.
Blebbing Through the Matrix
In multicellular...
Cell Polarization by Rho Proteins01:21

Cell Polarization by Rho Proteins

Cell polarity is the asymmetric distribution of cellular and membrane components, making one side of the cell different from the other. This polarity is essential to many processes such as embryogenesis, axon migration, glucose transport across epithelial cells, and directional cell migration. A migrating cell responds to intracellular or extracellular signals via molecular cascades that reorganize the actin cytoskeleton to establish this polarity. In these cells, the Rho family proteins Cdc42,...
Introduction to Fibroblasts01:09

Introduction to Fibroblasts

Rudolph Virchow discovered spindle-shaped cells called fibroblasts in 1858. Inactive fibroblasts, called fibrocytes, become activated by various stimuli, such as growth factors and inflammatory cytokines. Activated fibroblasts play a crucial role in wound healing, inflammation, formation of new blood vessels, and cancer progression. Uncontrolled activation of fibroblasts results in fibrosis, the excess deposition of fibrous tissue, which can lead to scarring and affect normal organs. This...
Small GTPases - Ras and Rho01:24

Small GTPases - Ras and Rho

Ras and Rho are small monomeric GTPases that act downstream of receptor tyrosine kinase (RTK) and regulate various cellular processes. These GTPases switch between active and inactive states by binding to guanine nucleotides.
Three regulatory proteins control their activity:
Cell-matrix's Response to Mechanical Forces01:13

Cell-matrix's Response to Mechanical Forces

In animal cells, the extracellular matrix allows cells within tissues to withstand external stresses and transmits signals from the outside of the cell to the inside. The extracellular matrix is extensive, and its composition varies between different types of tissues. For example, the reticular fibers and ground substance make up the ECM in loose connective tissue, while collagen and bone minerals make up the ECM of bone tissue. 
Anchoring junctions mechanically attach a cell to the...