The semaphorin/collapsin gene family is a large and diverse family encoding both secreted and transmembrane proteins, some of which are thought to act as repulsive axon guidance molecules. However, the function of most semaphorins is still unknown. We have cloned and characterized several semaphorins in the zebrafish in order to assess their in vivo function. Zebrafish semaZ2 is expressed in a ...

Class 3 semaphorins are anti-angiogenic and anti-tumorigenic guidance factors that bind to neuropilins, which, in turn, associate with class A plexins to transduce semaphorin signals. To study the role of the plexin-A2 receptor in semaphorin signaling, we silenced its expression in endothelial cells and in glioblastoma cells. The silencing did not affect Sema3A signaling, which depended on neur...

In human skeletal muscle, myoblasts represent the main population of myogenic progenitors. We previously showed that, beside their myogenic differentiation capacities, myoblasts also differentiate towards osteogenic and chondrogenic lineages, some properties generally considered being hallmarks of mesenchymal stem cells (MSCs). MSCs are also characterized by their immunosuppressive potential, t...

Statoacoustic ganglion (SAG) neurons project sensory afferents to appropriate targets in the inner ear to form functional vestibular and auditory circuits. Neuropilin1 (Npn1), a receptor for class 3 semaphorins, is required to generate appropriate afferent projections in SAG neurons; however, the ligands and coreceptors involved in Npn1 functioning remain unknown. Here we show that both plexinA...

Secreted Semaphorin3A (Sema3A) proteins are known to act as diffusible and repellant axonal guidance cues during nervous system development. A receptor complex consisting of a Neuropilin and a Plexin-A mediates their effects. Plexin-A signal transduction has remained poorly defined despite the documented involvement of collapsin response mediator protein and molecule interacting with CasL prote...

The large, conserved semaphorin/collapsin gene family encodes putative axon guidance molecules. We describe the cloning and expression of two n ovel zebrafish semaphorins that represent an increase in the size and diversity of the family. These semaphorins are expressed in unique and dynamic patterns during development.

Plexins belonging to the plexin-A subfamily form complexes with neuropilins and propagate signals of class 3 semaphorins into neurons, even though they do not directly bind the semaphorins. In this study, we identified a new member of the plexin-A subfamily in the mice, plexin-A4, and showed that it was expressed in the developing nervous system with a pattern different to that of other members...

Collapsin response mediator proteins (CRMPs) have been implicated in signaling of axonal guidance, including semaphorins. We have previously identified a unique member of this gene family, CRMP-associated molecule CRAM (CRMP-5), which is phylogenetically divergent from the other four CRMPs. In this study, we have examined the distribution and function of CRAM in developing neurons. Immunohistoc...