Semaphorins are secreted or transmembrane proteins that regulate cell motility and attachment in axon guidance, vascular growth, immune cell regulation and tumour progression.

Members

Function

Semaphorins are a large family of secreted or cell-bound signals, known to guide axons in developing nervous tissue.

They are expressed in a variety of adult and embryonic tissues and are thought to have a broader spectrum of functions.

Semaphorins and their receptors play a key role in the control of cellular interactions, most likely in cell-cell repulsion. A subset of semaphorins interacts with neuropilins - cell-surface molecules lacking a signalling-competent cytoplasmic domain. Another large family of transmembrane molecules, namely plexins, bind specifically to semaphorins. Thus plexins, alone, or in association with neuropilins, behave as fully functional semaphorin receptors.

The main receptors for semaphorins are plexins, which have established roles in regulating Rho-family GTPases. Plexins can influence R-Ras, which, in turn, can regulate integrins.

References

 Kruger RP, Aurandt J, Guan KL. Semaphorins command cells to move. Nat Rev Mol Cell Biol. 2005 Oct;6(10):789-800. PMID: #16314868#

 Tamagnone L, Comoglio PM. Signalling by semaphorin receptors: cell guidance and beyond.Trends Cell Biol. 2000 Sep;10(9):377-83. PMID: #10932095#