NACHT, LRR and PYD domains-containing protein 2 is a

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...

that in humans is encoded by the ''NLRP2''

gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...

. NALP proteins, such as NALP2, are characterized by an N-terminal

pyrin domain A pyrin domain (PYD, also known as PAAD/DAPIN) is a protein domain and a subclass of protein motif known as the death fold, the 4th and most recently discovered member of the death domain superfamily (DDF). It was originally discovered in the pyr ...

(PYD) and are involved in the activation of caspase-1 (CASP1; MIM 147678) by Toll-like receptors(see TLR4). They may also be involved in protein complexes that activate proinflammatory caspases (Tschopp et al., 2003). upplied by OMIMref name="entrez">

Function

The NLRP2 gene is one of the family members of nucleotide-binding and

leucine Leucine (symbol Leu or L) is an essential amino acid that is used in the biosynthesis of proteins. Leucine is an α-amino acid, meaning it contains an α-amino group (which is in the protonated −NH3+ form under biological conditions), an α- ca ...

-rich repeat receptor (NLR). Information from many literature sources indicates that an N-terminal pyrin effector domain (PYD) is one of the components of the NLRP2 gene. Other components include a centrally-located

nucleotide Nucleotides are organic molecules consisting of a nucleoside and a phosphate. They serve as monomeric units of the nucleic acid polymers – deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), both of which are essential biomolecules wi ...

-binding and oligomerization domain (NACHT) and C-terminal leucine-rich repeats (LRR). The products of NLRP2 gene are known to interact with IkB kinase (IKK) complex components. It can also regulate the activities of both caspase-1 and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB). The pyrin domain is essential and adequate to suppress the activities of NF-kB (Minkiewicz, de Rivero Vaccari and Keane 1113). An allelic variant (rs147585490) is known to block the NF-kB transcriptional activities. NLRP2 gene is one of the NLR family; it is believed to contribute to the regulation of immune responses (Minkiewicz, de Rivero Vaccari and Keane 1121). Although it is not well understood, the NLRP2 gene is responsible for maintaining fertility in females and contributes to the normal birth. The NPRP2 gene encodes for a human protein known as “NACHT, LRR and PYD domains-containing protein 2”. NALP2, which is one of the NALP proteins, has an N-terminal pyrin characterization also encoded as MIM 608107 and PYD domain. The NALP2 protein has a role in the activation process of caspase-1, which is encoded as CASP1; MIM 147678. The activation process occurs through the Toll-like receptors. The NALP2 may also take part in protein complexes, which initiates the activation of proinflammatory caspases. NLR family regulates the functioning of the

immune system The immune system is a network of biological processes that protects an organism from diseases. It detects and responds to a wide variety of pathogens, from viruses to parasitic worms, as well as cancer cells and objects such as wood splinte ...

, which technically compromises the normal functions of the body including reproduction.

Discovery

The NLR gene family where the NLRP2 gene belongs was first extracted from zebrafish, which is a common specimen for the study of immune systems. The NLRP2 gene is believed to have originated from the NLR gene family through

mutation In biology, a mutation is an alteration in the nucleic acid sequence of the genome of an organism, virus, or extrachromosomal DNA. Viral genomes contain either DNA or RNA. Mutations result from errors during DNA or viral replication, mi ...

. The mutation was initiated by the need for organisms to fit a dynamic environment and diversification in the evolution stages. Also, the mutation of the NLR gene family proteins was also due to the ability of pathogens to subvert the defense mechanism of the host. Therefore, the organisms were forced to device new ways of detecting and counteracting the effects of the resistant

pathogens In biology, a pathogen ( el, πάθος, "suffering", "passion" and , "producer of") in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a germ ...

. The evolution of the NLR proteins defines the origin of the NLRP2 gene. The NLRP2 gene is now an innate immune sensor for pathogens and sterile stress signal (SSS) in multi-cellular organisms.

Mutation and infertility

The deficiency of NLRP2 gene results in the inhibition of the activation of oocytes. The NLRP2 gene is exclusively expressed in oocytes. Therefore, it regulates the quality of the oocytes, which explains its relation to infertility in females.

Function

Discovery

Mutation and infertility

References

Further reading