Related Experiment Video

Updated: Jun 21, 2026

Mitochondrial Transformation in Baker's Yeast to Study Translation and Respiratory Complex Assembly
09:53

Mitochondrial Transformation in Baker's Yeast to Study Translation and Respiratory Complex Assembly

Published on: June 7, 2024

A mediator of Rho-dependent invasion moonlights as a methionine salvage enzyme

Yukihito Kabuyama1, Elizabeth S Litman, Paul D Templeton

  • 1Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, USA.

Molecular & Cellular Proteomics : MCP
|July 22, 2009
PubMed

Insights

A newly discovered protein, mediator of RhoA-dependent invasion (MRDI), promotes melanoma cell invasion and metastasis. MRDI

Area of Science:

  • Cell Biology
  • Cancer Research
  • Proteomics

Background:

  • RhoA signaling pathway regulates cell morphology and invasion, crucial in cancer progression.
  • RhoA activation is selectively observed in metastatic melanoma cells.

Purpose of the Study:

  • To identify proteins regulated by RhoA using functional proteomics.
  • To characterize a novel protein, mediator of RhoA-dependent invasion (MRDI), involved in melanoma cell invasion.

Main Methods:

  • Functional proteomics to identify RhoA-regulated proteins.
  • Analysis of MRDI expression and localization in melanoma cell lines and tissues.
  • Investigating MRDI's role in cell motility, focal adhesion kinase phosphorylation, and actin cytoskeleton dynamics.
  • Enzymatic assays to determine MRDI's catalytic activity.

Main Results:

  • Identified a novel protein, MRDI, induced by RhoA activation in metastatic melanoma cells.
  • MRDI expression and localization correlate with melanoma stage, shifting from nuclear to cytoplasmic/plasma membrane.
  • MRDI promotes cell invasion, motility, and modulates focal adhesion kinase and actin stress fibers.
  • Discovered MRDI possesses isomerase activity, essential for methionine salvage, but distinct from its invasion-promoting function.

Conclusions:

  • MRDI is a key mediator of RhoA-driven melanoma cell invasion and metastasis.
  • MRDI's dual role highlights the evolution of signaling pathways from ancient metabolic functions.
  • MRDI represents a potential therapeutic target for advanced melanoma.

More Related Videos

RhoC GTPase Activation Assay09:58

RhoC GTPase Activation Assay

Published on: August 22, 2010

A Reporter Assay to Analyze Intronic microRNA Maturation in Mammalian Cells06:48

A Reporter Assay to Analyze Intronic microRNA Maturation in Mammalian Cells

Published on: June 16, 2022

Related Concept Videos

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 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,...
The Ras Gene02:38

The Ras Gene

The Ras-gene-encoded proteins are regulators of signaling pathways controlling cell proliferation, differentiation, or cell survival. The Ras-gene family in humans constitutes three primary members—the HRas, NRas, and KRas. These genes code for four functionally distinct yet closely related proteins—the HRas, NRas, KRas4A, and KRas4B. The involvement of mutant Ras genes in human cancer was first discovered in 1982 and is among the most common causes of human tumorigenesis.
Ras is a superfamily...
Rab Proteins01:14

Rab Proteins

Rab proteins constitute the largest family of monomeric GTPases, of which 70 members are present in humans. Rab proteins and their effectors regulate consecutive stages of vesicle transport such as vesicle transport, docking, and fusion to the correct recipient membrane.
Rab proteins switch between a cytosolic, GDP-bound inactive state and a membrane-anchored, GTP-bound active state. By themselves, Rabs show slow rates of GDP/GTP exchange and GTP hydrolysis. Thus, Rab proteins are considered...
Translocation of Proteins into the Mitochondria01:19

Translocation of Proteins into the Mitochondria

Mitochondrial precursors are translocated to the internal subcompartments via independent mechanisms involving distinct protein machineries called translocases.
Sorting of outer membrane proteins:
Mitochondrial outer membrane proteins are of two types: the transmembrane, beta-barrel porins, and the membrane-anchored, alpha-helical proteins. Beta-barrel porin precursors are translocated by the TOM complex and inserted into the outer mitochondrial membrane by the SAM complex. In contrast,...
Regulation of Nuclear Protein Sorting01:45

Regulation of Nuclear Protein Sorting

Nuclear protein sorting regulates nucleus composition and gene expression, crucial for determining the fate of a eukaryotic cell. Hence, the entry and exit of molecules across the nuclear envelope is a tightly controlled process. Nuclear protein sorting can be inhibited by one of the following ways: 1) masking cargo signal sequences, 2) modifying the nuclear receptor's affinity for cargo, 3) controlling the nuclear pore size, 4) retaining the cargo during its transit to the cytosol or the...