semaphorins การใช้

• Within neural tissues, the plexin family serves as transmembrane receptors for Semaphorins.
• Semaphorins are a family of chemical signaling molecules involved in axonal targeting and guidance.
• Receptor complexes for semaphorins include neuropilins and plexins
• See, for example, FMR1, Thrombospondin, semaphorins, and Amyloid precursor protein.
• Fig . 5 : Semaphorins can exist either in a soluble form or membrane bound form.
• In addition, several other cell surface molecules have been shown to interact with secreted Semaphorins.
• Both are utilized in axonal repulsion, but recent studies demonstrate that Semaphorins can also mediate attraction.
• Class III semaphorins regulate multiple processes after spinal cord injury by influencing neuronal and non-neuronal cells.
• They are transmembrane glycoproteins, and predominantly co-receptors for another class of proteins known as semaphorins.
• Class 3 semaphorins are one of the most versatile semaphorin classes, in which Sema3a is the most studied.
• Class 3 semaphorins have an important function after traumatic central nervous system injuries, such as spinal cord injury.
• Class 3 semaphorins modulate axonal regrowth, re-myelination and the immune response after central nervous system trauma.
• Class 3 semaphorins ( SEMA3s ), originally identified as axon guidance molecules, play a role in remyelination.
• Semaphorins are involved in guidance of axonal migration during neuronal development and in immune responses . [ supplied by OMIM]
• The multitude of molecules that complex with Semaphorins may be the result of the ubiquitous nature of Semaphorin expression in vertebrates.
• Semaphorins are a large family of secreted or membrane-bound proteins that mediate repulsive effects on axon pathfinding during nervous system development.
• While the previous example suggested that Semaphorins may play pivotal roles in maintaining viable neurons, for the most part Semaphorin knockout animals display mild phenotypes.
• A subset of semaphorins are recognized by plexin-A / neuropilin transmembrane receptor complexes, triggering a cellular signal transduction cascade that leads to axon repulsion.
• Semaphorins have also been shown to mediate other neuronal processes besides targeting such as : apoptosis, cell migration, axon pruning, synaptic transmission, and axonal transport.