Neuropilin
Neuropilin
Protein receptor active in neurons
Neuropilin is a protein receptor active in neurons.
There are two forms of Neuropilins, NRP-1 and NRP-2. Neuropilins are transmembrane glycoproteins, first documented to regulate neurogenesis and angiogenesis by complexing with Plexin receptors/class-3 semaphorin ligands and Vascular Endothelial Growth Factor (VEGF) receptors/VEGF ligands, respectively.[2][3] Neuropilins predominantly act as co-receptors as they have a very small cytoplasmic domain and thus rely upon other cell surface receptors to transduce their signals across a cell membrane.[2][3] Recent studies have shown that Neuropilins are multifunctional and can partner with a wide variety of transmembrane receptors. Neuropilins are therefore associated with numerous signalling pathways including those activated by Epidermal Growth Factor (EGF), Fibroblast Growth Factor (FGF), Hepatocyte Growth Factor (HGF), Insulin-like Growth Factor (IGF), Platelet Derived Growth Factor (PDGF) and Transforming Growth Factor beta (TGFβ).[4][5] Although Neuropilins are commonly found at the cell surface, they have also been reported within the mitochondria and nucleus.[6][7] Both Neuropilin family members can also be found in soluble forms created by alternative splicing or by ectodomain shedding from the cell surface.[8][9]
The pleiotropic nature of the NRP receptors results in their involvement in cellular processes, such as axon guidance and angiogenesis, the immune response and remyelination.[10] Therefore, dysregulation of NRP activity has been implicated in many pathological conditions, including many types of cancer and cardiovascular disease.[11][12][13][14]