Notch 1

Notch homolog 1, translocation-associated (Drosophila), also known as NOTCH1, is a human gene encoding a single-pass transmembrane receptor.

Function

This gene encodes a member of the Notch family. Members of this Type 1 transmembrane protein family share structural characteristics including an extracellular domain consisting of multiple epidermal growth factor-like (EGF) repeats, and an intracellular domain consisting of multiple, different domain types. Notch family members play a role in a variety of developmental processes by controlling cell fate decisions. The Notch signaling network is an evolutionarily conserved intercellular signaling pathway that regulates interactions between physically adjacent cells. In Drosophila, notch interaction with its cell-bound ligands (delta, serrate) establishes an intercellular signaling pathway that plays a key role in development. Homologues of the notch-ligands have also been identified in human, but precise interactions between these ligands and the human notch homologues remain to be determined. This protein is cleaved in the trans-Golgi network, and presented on the cell surface as a heterodimer. This protein functions as a receptor for membrane bound ligands, and may play multiple roles during development.

HN1 (gene)

Hematological and neurological expressed 1 protein is a protein that in humans is encoded by the HN1 gene.

NOTE: HN1 can also refer to the Notch 1 gene.

References

Further reading

HN1 (nitrogen mustard)

Bis(2-chloroethyl)ethylamine is the organic compound with the formula C₂H₅N(CH₂CH₂Cl)₂. Often abbreviated HN1, it is a powerful vesicant and a nitrogen mustard gas used for chemical warfare. HN1 was developed in the 1920s and 1930s to remove warts and later as a military agent. Because of the latter use, it is a Schedule 1 chemical within the Chemical Weapons Convention and therefore use and production is strongly restricted. It has never been used in warfare.

It is an oily liquid with a colorless to pale yellow appearance and a faint fishy or musty odor. HN1 is also an alkylating agent.

Reactions

Nitrogen mustards react via an initial cyclization to the corresponding aziridinium salt. The rate of this reaction is pH dependent because the protonated amine cannot cyclize. The aziridinium ion reacts with water in a slower reaction. At pH 8, the nitrogen mustards are essentially quantitatively converted to the aziridinium ion for subsequent slow reaction with water. In contrast, at pH 4 cyclization and hydrolysis show the classic form of reactions in series. Hydrolysis of HN1 produces toxic intermediates.