Related Experiment Video

Updated: Jun 20, 2026

Characterize Disease-related Mutants of RAF Family Kinases by Using a Set of Practical and Feasible Methods
07:49

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

Published on: July 17, 2019

Sprouty2 association with B-Raf is regulated by phosphorylation and kinase conformation

Suzanne C Brady1, Mathew L Coleman, June Munro

  • 1The Beatson Institute for Cancer Research, Glasgow, United Kingdom.

Cancer Research
|August 20, 2009
PubMed

Insights

Sprouty2 phosphorylation and B-Raf conformation control Sprouty2 binding to B-Raf, impacting the Ras/Raf/MEK/extracellular signal-regulated kinase (MAPK) pathway. This reveals how cancer cells evade Sprouty2

Area of Science:

  • Molecular Biology
  • Cell Signaling
  • Cancer Research

Background:

  • Sprouty2 negatively regulates the Ras/Raf/MEK/extracellular signal-regulated kinase (MAPK) pathway.
  • Down-regulation of Sprouty2 is common in human cancers, suggesting a tumor suppressor role.
  • Up-regulation of Sprouty2 in some cancers indicates posttranscriptional regulation allowing evasion of its tumor-suppressive functions.

Purpose of the Study:

  • To investigate the posttranscriptional mechanisms regulating Sprouty2's interaction with B-Raf.
  • To elucidate how Sprouty2 phosphorylation and B-Raf mutations affect Sprouty2 binding and MAPK pathway regulation.

Main Methods:

  • Site-directed mutagenesis to create nonphosphorylatable Sprouty2 alanine mutants.
  • Analysis of Sprouty2 association with wild-type and mutant B-Raf.
  • Assessment of Sprouty2's ability to inhibit growth factor-induced MAPK activation.

Main Results:

  • MAPK activation induces Sprouty2 phosphorylation, reducing its binding to wild-type B-Raf.
  • Mutating phosphorylation sites on Sprouty2 enhances its inhibitory effect on MAPK activation.
  • Oncogenic B-Raf V600E mutants do not bind Sprouty2 due to their active conformation, independent of phosphorylation.

Conclusions:

  • Sprouty2 phosphorylation and B-Raf conformation represent a dual mechanism controlling Sprouty2/B-Raf interaction.
  • These mechanisms contribute to the evasion of Sprouty2-mediated antitumorigenic effects in cancer.
  • Understanding these interactions is crucial for targeting the MAPK pathway in cancer therapy.

More Related Videos

Bioluminescence Resonance Energy Transfer (BRET)-Based Assay for Measuring Interactions of CRAF with 14-3-3 Proteins in Live Cells06:44

Bioluminescence Resonance Energy Transfer (BRET)-Based Assay for Measuring Interactions of CRAF with 14-3-3 Proteins in Live Cells

Published on: March 1, 2024

Light-mediated Reversible Modulation of the Mitogen-activated Protein Kinase Pathway during Cell Differentiation and Xenopus Embryonic Development09:32

Light-mediated Reversible Modulation of the Mitogen-activated Protein Kinase Pathway during Cell Differentiation and Xenopus Embryonic Development

Published on: June 15, 2017

Related Concept Videos

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...
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...
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...
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...
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...