Related Experiment Video

Updated: Aug 29, 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

Functional analysis of mutations within the kinase activation segment of B-Raf in human colorectal tumors

Tsuneo Ikenoue1, Yohko Hikiba, Fumihiko Kanai

  • 1Division of Gastroenterology, The Institute for Adult Diseases, Asahi Life Foundation, Tokyo, Japan. t-ikenoue@asahi-life.or.jp

Cancer Research
|December 18, 2003
PubMed

Insights

B-Raf V599E and K600E mutations significantly activate Erk and NFkappaB pathways, promoting NIH3T3 cell transformation. Other B-Raf mutations in colorectal tumors may not drive cancer by increasing kinase activity.

Area of Science:

  • Oncology
  • Molecular Biology
  • Cancer Genetics

Background:

  • B-Raf gene mutations are implicated in human cancers, notably colorectal carcinoma.
  • The V599E mutation is the most prevalent B-Raf alteration, but the functional impact of other mutations remains unclear.

Purpose of the Study:

  • To investigate the functional consequences of colon tumor-associated B-Raf mutations within the kinase activation segment.
  • To assess the impact of these mutations on extracellular signal-regulated kinase (Erk) and nuclear factor kappaB (NFkappaB) signaling pathways.
  • To evaluate the effect on NIH3T3 fibroblast transformation.

Main Methods:

  • Analysis of six distinct B-Raf mutations within the kinase activation segment.
  • Assay of Erk and NFkappaB signaling pathway activation.
  • Assessment of NIH3T3 fibroblast transforming activity.

Main Results:

  • B-Raf V599E and K600E mutations markedly enhanced Erk and NFkappaB signaling and NIH3T3 cell transformation.
  • B-Raf F594L mutation showed moderate increases in Erk signaling and NIH3T3 transformation, with no significant NFkappaB activation.
  • B-Raf T598I, D593V, and G595R mutants exhibited reduced or unaltered kinase activity, with minimal impact on signaling pathways and transformation.

Conclusions:

  • B-Raf V599E and K600E are potent activators of oncogenic signaling pathways.
  • B-Raf activation segment mutations, beyond V599E, may not universally contribute to colorectal carcinogenesis through enhanced kinase or transforming activity.

More Related Videos

Deciphering the Structural Effects of Activating EGFR Somatic Mutations with Molecular Dynamics Simulation15:05

Deciphering the Structural Effects of Activating EGFR Somatic Mutations with Molecular Dynamics Simulation

Published on: May 20, 2020

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

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...
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...