Ras-mapk Pathway
Ras-mapk Pathway - Related Videos
08:54
Imaging Spatial Reorganization of a MAPK Signaling Pathway Using the Tobacco Transient Expression System
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Cited by 4 •
2016
At the subcellular level, signaling events are dynamically modulated by developmental and environmental cues. Here we describe a protocol that employs the tobacco transient expression system to monitor dynamic protein-protein interaction and to disclose spatial organization of signal transduction in plant cells.
02:38
The Ras Gene
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2021
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...
02:38
The Ras Gene
0 Views •
2023
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...
01:24
Small GTPases - Ras and Rho
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2023
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: Guanine nucleotide exchange factors or GEF, GTPase-activating proteins or GAPs, and Guanine nucleotide-dissociation inhibitors or GDIs. The GEF activates the GTPase by exchanging the bound-GDP with GTP. The GTPases’...
01:07
MAPK Signaling Cascades
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2023
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...
FAQs
Growth-factor binding to a receptor tyrosine kinase initiates the molecular switch that activates Ras. The critical change is exchange of GDP for GTP, converting Ras into its active form. This step links an extracellular signal to intracellular signaling and determines whether the downstream RAF, MEK, and ERK kinase cascade can proceed.
The RAF-MEK-ERK sequence organizes signal transmission through successive kinase activities. Activated Ras triggers RAF, RAF activates MEK, and MEK activates ERK. Once activated, ERK can enter the nucleus and regulate transcription, allowing a signal that begins at the cell surface to influence gene expression and cellular behaviors such as proliferation or differentiation.
Regulatory feedback provides a way to evaluate and control signaling after the initial activation sequence. Studying feedback alongside Ras, RAF, MEK, and ERK helps explain how pathway activity is adjusted rather than viewed as a simple one-way chain. This perspective is important when analyzing signaling defects and identifying possible points for therapeutic intervention.
Abnormal activation can keep signaling through the pathway in a disease-associated state, disrupting the normal control of cell behavior. Because the network regulates proliferation, differentiation, survival, and migration, altered activity may affect several cancer-relevant processes at once. Examining where signaling becomes abnormal helps researchers connect biochemical defects with disease development.
A biochemical analysis can examine the pathway as a linked set of components, beginning with receptor tyrosine kinase input and following Ras activation through RAF, MEK, and ERK. Researchers can then relate ERK-dependent transcription to changes in cell behavior and include regulatory feedback in the analysis. This approach connects molecular events with broader cellular outcomes.
Mapping the network supports drug-target identification and analysis of signaling defects in disease. Its components provide distinct points for examining how extracellular cues are converted into transcriptional and behavioral responses. In biochemistry and cell research, this framework helps investigators relate altered molecular signaling to changes in proliferation, differentiation, survival, migration, and cancer-associated behavior.