detection of muramyl dipeptide

Definition

Target type: biologicalprocess

The series of events in which a muramyl dipeptide stimulus is received by a cell and converted into a molecular signal. Muramyl dipeptide is derived from peptidoglycan. [GOC:rl, PMID:15998797]

Muramyl dipeptide (MDP) is a potent immunostimulatory molecule that is recognized by the innate immune system. It is a derivative of peptidoglycan, a major component of bacterial cell walls. The detection of MDP involves a complex interplay of cellular receptors, signaling pathways, and downstream effector mechanisms.

The key receptor involved in MDP recognition is **Nod2**, a cytosolic pattern recognition receptor (PRR) expressed in various immune cells, including macrophages, dendritic cells, and epithelial cells. Nod2 contains a leucine-rich repeat (LRR) domain that binds to MDP.

Upon MDP binding, Nod2 undergoes a conformational change, leading to its oligomerization and the recruitment of adaptor proteins, such as **RIP2** (receptor interacting protein 2). RIP2 is a serine-threonine kinase that activates the **NF-κB** signaling pathway.

The activation of NF-κB triggers the transcription of pro-inflammatory cytokines, including **TNF-α, IL-6, and IL-1β**. These cytokines play a crucial role in the initiation of immune responses, such as the recruitment of immune cells to the site of infection and the activation of adaptive immunity.

In addition to NF-κB activation, Nod2 signaling also leads to the activation of **MAPKs** (mitogen-activated protein kinases) and **IRF5** (interferon regulatory factor 5). MAPKs are involved in regulating cell growth and survival, while IRF5 promotes the production of type I interferons, which are antiviral cytokines.

The detection of MDP by Nod2 initiates a complex cascade of signaling events that ultimately lead to the activation of immune responses. This process is essential for the host's defense against bacterial infections. MDP recognition by Nod2 also plays a role in the development of inflammatory bowel diseases and other autoimmune disorders.'
"

Proteins (2)

Compounds (12)