Fig. 6. The combination of the transmembrane and cytoplasmic regions of UNC-5 were necessary and sufficient for the regulation by UNC-51. (A-R) UNC-5 has two Ig domains, two TSP domains, a transmembrane domain (TM), a ZU-5 domain and a DD domain. SS represents the UNC-40 signal sequence. (A,H,I) Full-length UNC-5. (B,J,K) Deletion of the extracellular region. (C,L,M) Deletion of the cytoplasmic region. (D,N) Only the cytoplasmic region. (E,O) Extracellular region alone. (F,P) Transmembrane domain alone. (G,Q,R) Full-length UNC-5, including the UNC-40 signal sequence at the N-terminus. All the proteins were expressed as GFP-fusion proteins in DD/VD neurons using the unc-25 promoter. `Wild type' indicates that the fusion proteins were expressed in wild type. `unc-51(e369)' indicates that the fusion proteins were expressed in unc-51(e369). (H,J,L,M,Q) Localization to small vesicles. In the cases of L and M, the vesicles were larger than those of wild type. (I,K,O,R) Accumulation in the cell bodies. (N) Localization to the nucleus. (P) Localization to the cytoplasm.