Neurexin

Neurexin

A neurexin (NRXN) is a presynaptic protein that helps to glue together neurons at the synapse.[1] Neurexins are type I membrane proteins that can be classified into two types, α-NRXNs and β-NRXNs. The α-NRXNs are larger and have different amino-terminal extracellular sequences. Neurexins mediate signaling across the synapse, and affect the properties of neural networks by specifying synaptic functions. In humans, alterations in genes encoding neurexins are implicated in autism and other cognitive diseases.[2]

Neurexins were discovered as receptors for α-latrotoxin, a toxin in black widow spider venom.[2] Their functional roles in insects are likely similar to those in vertebrates.[3]

β-Neurexins (located presynaptically) act as receptors for neuroligin (located postsynaptically). Neurexin and neuroligin "shake hands," resulting in the connection between the two neurons and the production of a synapse.[4] Additionally, β-Neurexin has also been found to play a role in angiogenesis.[5]

The neurexin genes are NRXN1, NRXN2, and NRXN3.[2]

See also

References

  1. ^ Li X, Zhang J, Cao Z, Wu J, Shi Y (2006). "Solution structure of GOPC PDZ domain and its interaction with the C-terminal motif of neuroligin". Protein Sci. 15 (9): 2149–58. doi:10.1110/ps.062087506. PMC 2242614. PMID 16882988. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2242614. 
  2. ^ a b c Südhof TC (2008). "Neuroligins and neurexins link synaptic function to cognitive disease". Nature 455 (7215): 903–11. doi:10.1038/nature07456. PMC 2673233. PMID 18923512. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2673233. 
  3. ^ Biswas S, Russell RJ, Jackson CJ et al. (2008). Grant, Seth G. N.. ed. "Bridging the synaptic gap: neuroligins and neurexin I in Apis mellifera". PLoS ONE 3 (10): e3542. doi:10.1371/journal.pone.0003542. PMC 2570956. PMID 18974885. http://www.plosone.org/article/info:doi/10.1371/journal.pone.0003542. 
  4. ^ Scheiffele P, Fan J, Choih J, Fetter R, Serafini T (2000) (2000). "Neuroligin Expressed in Nonneuronal Cells Triggers Presynaptic Development in Contacting Axons". Cell 101 (6): 657–669. doi:10.1016/S0092-8674(00)80877-6. PMID 10892652. 
  5. ^ Bottos A, Destro E, Rissone A, Graziano S, Cordara G, Assenzio B, Cera MR, Mascia L, Bussolino F, Arese M. (2009). The synaptic proteins neurexins and neuroligins are widely expressed in the vascular system and contribute to its functions. Proc Natl Acad Sci U S A. 106:20782–20787. doi:10.1073/pnas.0809510106 PMID 19926856