Semaphorin

Semaphorins (Greek for semaphore signal) are a class of secreted or membrane - associated proteins that are involved in the central nervous system by repulsive or attractive interaction with neuropilin and plexin receptors in axon guidance.

Function

A targeted muscle control is existential for each animal. To make this possible, even during the formation ( ontogeny ) must muscle fibers and motor neurons grow perfectly matched and are networked together. The distribution of semaphorin as Wegleitungsmolekül and the sensor semaphorin receptors on the nerve fibers enable the coordination performance. This means, for example, allows on the local irritation of the pressure sensors of a particular skin brain area, a pulse on its associated sensory nerves connection to the spinal cord or central nervous system is sent and the response via site-specific motor neurons activating very specific muscles for coordinated movement with high precision triggers.

Next to inducing the sprouting and growth of nerve cells (see, nerve growth factor ), it is also important to limit the growth so as not to overshoot the target. This growth restriction is also adopted by the semaphorins (along with probably other molecules ).

Subdivision

Semaphorins are divided into eight classes: 1 to 7 and V. classes 1 and 2 occur only in insects and worms, 3-7 in vertebrates, and V in viruses. Human semaphorin genes are:

• Sema3A, SEMA3B, SEMA3C, SEMA3D, SEMA3E, SEMA3F, SEMA3G
• SEMA4A, SEMA4B, SEMA4C ( " SEMAF " ), SEMA4D, SEMA4E, SEMA4F, SEMA4G
• SEMA5A, SEMA5B
• SEMA6A, SEMA6B, SEMA6C, SEMA6D,
• Sema7A

Single Documents

• Receptor
• Protein group
• Neurophysiology