Pi3k/akt pathway

Definition

The pi3k/akt pathway is a critical signaling cascade involved in cellular processes such as growth, survival, and metabolism. This pathway is activated by various growth factors and hormones, leading to the activation of the protein kinase Akt, which promotes cell survival and proliferation while inhibiting apoptosis. Its role extends beyond simple cell signaling, significantly impacting ECM remodeling and mechanotransduction as well.

5 Must Know Facts For Your Next Test

1. The activation of the pi3k/akt pathway is triggered by binding of growth factors to receptor tyrosine kinases (RTKs), leading to PI3K activation.
2. Akt phosphorylates a variety of substrates involved in regulating cellular functions such as glucose metabolism, protein synthesis, and cell cycle progression.
3. Dysregulation of the pi3k/akt pathway is often implicated in cancer, as it can lead to enhanced cell survival and proliferation.
4. In the context of ECM remodeling, the pi3k/akt pathway influences matrix metalloproteinases (MMPs), which are crucial for ECM degradation and remodeling.
5. The pi3k/akt pathway also plays a vital role in mechanotransduction by integrating mechanical signals with biochemical responses to influence cell behavior.

Review Questions

• How does the activation of the pi3k/akt pathway influence cell survival and growth?
  • The activation of the pi3k/akt pathway influences cell survival and growth by promoting various cellular processes. When growth factors bind to receptor tyrosine kinases, it activates PI3K, which leads to the phosphorylation of PIP2 to PIP3. This process activates Akt, which then phosphorylates key substrates that enhance cell survival and inhibit apoptosis, thereby fostering conditions for cell growth and proliferation.
• Discuss the relationship between the pi3k/akt pathway and ECM remodeling.
  • The pi3k/akt pathway plays a significant role in ECM remodeling by regulating matrix metalloproteinases (MMPs). These enzymes are responsible for degrading components of the extracellular matrix, facilitating tissue remodeling during growth and repair. Activation of Akt can enhance MMP expression, allowing cells to modulate their microenvironment effectively. This interplay highlights how cell signaling is intricately connected to ECM dynamics in both physiological and pathological contexts.
• Evaluate how alterations in the pi3k/akt pathway can contribute to cancer progression and therapy resistance.
  • Alterations in the pi3k/akt pathway can significantly contribute to cancer progression by promoting uncontrolled cell growth and survival. Mutations or overexpression of components within this pathway can lead to persistent Akt activation, resulting in enhanced resistance to apoptotic signals. This creates a challenging environment for cancer therapies, as these cells become less responsive to treatments aimed at inducing apoptosis. Understanding these alterations is crucial for developing targeted therapies that can effectively combat resistant cancer cells.

Related terms

Phosphoinositide 3-kinase (PI3K): An enzyme that phosphorylates the lipid phosphatidylinositol, creating signaling molecules that activate the Akt pathway.

Akt (Protein Kinase B): A serine/threonine kinase that is activated by the pi3k pathway, playing a key role in promoting cell growth, survival, and metabolism.

Apoptosis: The process of programmed cell death that is regulated by various signaling pathways, including the pi3k/akt pathway which can inhibit this process to promote cell survival.