 This suggests that neurofibromin has a role in the transportation of the NMDA receptor subunits to the synapse and its membrane.Neurofibromin is also believed to be involved in the synaptic ATP-PKA-cAMP pathway, through modulation of adenylyl cyclase.It is also known to bind the caveolin 1, a protein which regulates p21ras, PKC and growth response factors.