The interacting proteins and corresponding functions of neurofibromin. GRD, RasGAP-related domain; LRD, Leucine-rich domain; CTD, C-terminal domain. The amino acid (aa) residue number is based on the sequence of neurofibromin with type I GRD. The LRD can be further separated into the N-terminal Sec14-like domain (residue 1560-1699) for lipid binding and the C-terminal pleckstrin homology-like domain (residues 1713-1818). The braces indicate the interacting regions for each binding proteins. 1Note that the GRD and entire C-terminal region of neurofibromin are involved in activation of the adenylate cyclase. However, the mechanism is unknown. It is not clear whether the direct protein-protein interaction between neurofibromin and adenylate cyclase is involved.