response to hydroperoxide

Definition

Target type: biologicalprocess

Any process that results in a change in state or activity of a cell or an organism (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a hydroperoxide stimulus. Hydroperoxides are monosubstitution products of hydrogen peroxide, HOOH. [GOC:mah]

Response to hydroperoxide is a critical cellular defense mechanism against oxidative stress. Hydroperoxides, such as hydrogen peroxide (H2O2) and lipid hydroperoxides, are highly reactive molecules that can damage cellular components including DNA, proteins, and lipids. Cells have evolved a sophisticated network of antioxidant enzymes and pathways to detoxify hydroperoxides and mitigate their harmful effects.

The response to hydroperoxide begins with the detection of these reactive oxygen species (ROS). Cells possess various sensors that can perceive the presence of hydroperoxides, including redox-sensitive transcription factors, kinases, and phosphatases. These sensors undergo conformational changes or activation upon interaction with hydroperoxides, triggering downstream signaling cascades.

One key signaling pathway involved in the response to hydroperoxide is the activation of the Nrf2 transcription factor. Nrf2 is a master regulator of antioxidant gene expression. In normal conditions, Nrf2 is sequestered in the cytoplasm by Keap1, an adaptor protein that promotes its ubiquitination and degradation. Upon exposure to hydroperoxides, Keap1 undergoes conformational changes, leading to the release of Nrf2 from its inhibitory complex. Nrf2 translocates to the nucleus, where it binds to antioxidant response elements (AREs) in the promoter regions of genes involved in antioxidant defense.

The Nrf2-mediated transcriptional response results in the upregulation of a battery of antioxidant enzymes, including superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx), and glutathione reductase (GR). These enzymes play crucial roles in scavenging ROS and detoxifying hydroperoxides. SOD converts superoxide radicals into hydrogen peroxide, which is further degraded by catalase or GPx. GPx utilizes reduced glutathione (GSH) to reduce hydrogen peroxide into water, while GR regenerates GSH from its oxidized form.

Another important response to hydroperoxide is the activation of the MAPK signaling pathways, particularly JNK and p38. These kinases are activated by hydroperoxides through a complex cascade of signaling events. Activated JNK and p38 phosphorylate downstream target proteins, leading to the induction of various cellular responses, including apoptosis, cell cycle arrest, and inflammation.

The response to hydroperoxide can also involve the induction of autophagy, a cellular process that involves the degradation of damaged organelles and proteins. Autophagy plays a protective role in response to oxidative stress by removing damaged cellular components and promoting cell survival.

Overall, the response to hydroperoxide is a multifaceted process involving the activation of multiple signaling pathways, the upregulation of antioxidant enzymes, and the induction of cellular protective mechanisms. This intricate network of responses ensures cellular survival in the face of oxidative stress, safeguarding cellular integrity and preventing the development of various diseases associated with oxidative damage.'
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Proteins (6)

Compounds (220)