NXPH1 Human, Sf9

Neurexophilin 1 was initially discovered as a neuronal glycoprotein that co-purifies with neurexin Iα during affinity chromatography on immobilized α-latrotoxin . The neurexophilin family includes four genes in mammalian brains, all sharing a common structure composed of five domains:

1. N-terminal signal peptide
2. Variable N-terminal domain
3. Highly conserved central domain that is N-glycosylated
4. Short linker region
5. Conserved C-terminal domain that is cysteine-rich .

When expressed in neuron-like cells, Neurexophilin 1 undergoes N-glycosylation and is processed to a smaller mature form through endoproteolytic cleavage . This processing is crucial for its function and interaction with neurexins. Notably, only recombinant neurexin Iα and IIIα, but not neurexin Iβ, interact with Neurexophilin 1 .

Neurexophilin 1 functions as a neuropeptide, signaling via α-neurexins. This interaction is essential for synaptic function and neuronal communication . Additionally, Neurexophilin 1 has been shown to suppress the proliferation of hematopoietic progenitor cells, indicating its role beyond the nervous system . This suppression occurs through its interaction with Neurexin Iα (NRXN1α) and is modulated by Dystroglycan (DAG1) .

The recombinant form of Neurexophilin 1, produced in Sf9 cells, is used for research purposes to study its structure, function, and interactions. Sf9 cells, derived from the fall armyworm (Spodoptera frugiperda), are commonly used in recombinant protein production due to their high expression levels and post-translational modification capabilities.