Related Experiment Video

Updated: Aug 6, 2026

Assessment of Mitochondrial Functions and Cell Viability in Renal Cells Overexpressing Protein Kinase C Isozymes
15:43

Assessment of Mitochondrial Functions and Cell Viability in Renal Cells Overexpressing Protein Kinase C Isozymes

Published on: January 7, 2013

Protein kinase-dependent overexpression of the nuclear protein pirin in c-JUN and RAS transformed fibroblasts

A C Bergman1, A A Alaiya, W Wendler

  • 1Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.

Cellular and Molecular Life Sciences : CMLS
|May 6, 1999
PubMed

Insights

Inhibition of the Raf-MEK-ERK pathway alters protein expression in cancer cells. This study identifies key proteins affected by MEK1 inhibition, offering insights into oncogene-driven changes.

Area of Science:

  • Molecular Biology
  • Oncology
  • Cellular Signaling

Background:

  • The Raf-MEK-ERK pathway is crucial for oncogene-induced cell transformation.
  • Understanding how inhibiting this pathway affects gene expression is vital for cancer research.

Purpose of the Study:

  • To identify genes whose expression is altered by MEK1 inhibitor PD98059 in c-JUN transformed rat fibroblasts.
  • To elucidate the role of the Raf-MEK-ERK pathway in oncogene-induced cellular changes.

Main Methods:

  • Treatment of c-JUN transformed rat fibroblasts with MEK1 inhibitor PD98059.
  • Two-dimensional gel electrophoresis and mass spectrometry to analyze protein expression changes.
  • Western blot analysis to confirm protein expression levels.

Main Results:

  • MEK1 inhibition reduced the expression of pirin, alpha-enolase, phosphoglycerate kinase, elongation factor 2, and heterogeneous nuclear ribonucleoprotein A3.
  • Pirin expression was elevated in RAS and c-JUN transformed cells without PD98059.
  • Ornithine aminotransferase levels increased upon MEK1 inhibition.

Conclusions:

  • MEK1 inhibition significantly alters protein expression profiles in c-JUN transformed cells.
  • The Raf-MEK-ERK pathway plays a critical role in mediating oncogene-induced phenotypic alterations.

More Related Videos

Studying RNA Interactors of Protein Kinase RNA-Activated during the Mammalian Cell Cycle10:05

Studying RNA Interactors of Protein Kinase RNA-Activated during the Mammalian Cell Cycle

Published on: March 5, 2019

Characterize Disease-related Mutants of RAF Family Kinases by Using a Set of Practical and Feasible Methods07:49

Characterize Disease-related Mutants of RAF Family Kinases by Using a Set of Practical and Feasible Methods

Published on: July 17, 2019

Related Concept Videos

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...
mTOR Signaling and Cancer Progression03:03

mTOR Signaling and Cancer Progression

The mammalian target of rapamycin or mTOR protein was discovered in 1994 due to its direct interaction with rapamycin. The protein gets its name from a yeast homolog called TOR. The mTOR protein complex in mammalian cells plays a major role in balancing anabolic processes such as the synthesis of proteins, lipids, and nucleotides and catabolic processes, such as autophagy in response to environmental cues, such as availability of nutrients and growth factors.
The mTOR pathway or the...
Interactions Between Signaling Pathways01:19

Interactions Between Signaling Pathways

Signaling cascades usually lack linearity. Multiple pathways interact and regulate one another, allowing cells to integrate and respond to diverse environmental stimuli.
Convergence and divergence, and cross-talk between signaling pathways
Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response...
MAPK Signaling Cascades01:07

MAPK Signaling Cascades

Mitogen-activated protein kinase, or MAPK pathway, activates three sequential kinases to regulate cellular responses such as proliferation, differentiation, survival, and apoptosis. The canonical MAPK pathway starts with a mitogen or growth factor binding to an RTK. The activated RTKs stimulate Ras, which recruits Raf or MAP3 Kinase (MAPKKK), the first kinase of the MAPK signaling cascade. Raf further phosphorylates and activates MEK or MAP2 Kinases (MAPKK), which in turn phosphorylates MAP...
The JAK-STAT Signaling Pathway01:20

The JAK-STAT Signaling Pathway

Several cytokine receptors have tightly bound Janus kinase or JAK proteins attached at their cytosolic tail. Small signaling molecules such as cytokines, growth hormones, or prolactins bind to the cytokine receptors and initiate their dimerization. The dimerization brings the cytosolic JAKs together that trans-phosphorylate and activates each other. The activated JAKs now phosphorylate cytosolic tails of the cytokine receptors, which serve as binding sites for adaptor proteins such as  SH2...
PI3K/mTOR/AKT Signaling Pathway01:22

PI3K/mTOR/AKT Signaling Pathway

The mammalian target of rapamycin  (mTOR) is a serine/threonine kinase that regulates growth, proliferation, and cell survival in response to hormones, growth factors, or nutrient availability. This kinase exists in two structurally and functionally distinct forms: mTOR complex 1  (mTORC1) and mTOR complex 2  (mTORC2). The first form (mTORC1) is composed of a rapamycin-sensitive Raptor and proline-rich Akt substrate, PRAS40. In contrast,  mTORC2 consists of a rapamycin-insensitive companion...