Nucleotide-binding oligomerization domain-containing protein 1 is a protein

Protein

Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...

 receptor that in humans is encoded by the NOD1 gene

Gene

A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...

. It recognizes bacterial molecules and stimulates an immune reaction.

NOD1 protein contains a caspase recruitment domain (CARD). NOD1 is a member of NOD-like receptor protein family and is a close relative of NOD2

NOD2

Nucleotide-binding oligomerization domain-containing protein 2 also known as caspase recruitment domain-containing protein 15 or inflammatory bowel disease protein 1 is a protein that in humans is encoded by the NOD2 gene located on chromosome 16. NOD2 plays an important role in the immune system...

. NOD1 is an intracellular pattern recognition receptor

Pattern recognition receptor

Pattern recognition receptors are a primitive part of the immune system. They are proteins expressed by cells of the innate immune system to identify pathogen-associated molecular patterns , which are associated with microbial pathogens or cellular stress, as well as damage-associated molecular...

, which is similar in structure to resistant proteins of plants, and mediates innate

Innate immune system

The innate immune system, also known as non-specific immune system and secondary line of defence, comprises the cells and mechanisms that defend the host from infection by other organisms in a non-specific manner...

 and acquired immunity

Adaptive immune system

The adaptive immune system is composed of highly specialized, systemic cells and processes that eliminate or prevent pathogenic growth. Thought to have arisen in the first jawed vertebrates, the adaptive or "specific" immune system is activated by the “non-specific” and evolutionarily older innate...

 by recognizing bacterial molecules containing D-glutamyl-meso-diaminopimelic acid (iE-DAP) moiety. Nod1 interacts with RIPK2

RIPK2

Receptor-interacting serine/threonine-protein kinase 2 is an enzyme that in humans is encoded by the RIPK2 gene.-Further reading:...

 through the CARDs of both molecules (See the structure of the NOD1 CARD in the right panel). Stimulation of NOD1 by iE-DAP containing molecules results in activation of the transcription factor NF-κB.