Cloning and characterization of neuropilin-1-interacting protein: a PSD-95/Dlg/ZO-1 domain-containing protein that interacts with the cytoplasmic domain of neuropilin-1.
Neuropilin-1 (Npn-1), a receptor for semaphorin III, mediates the guidance of growth cones on extending neurites. The molecular mechanism of Npn-1 signaling remains unclear. We have used a yeast two-hybrid system to isolate a protein that interacts with the cytoplasmic domain of Npn-1. This Npn-1-interacting protein (NIP) contains a central PSD-95/Dlg/ZO-1 (PDZ) domain and a C-terminal acyl carrier protein domain. The physiological interaction of Npn-1 and NIP is supported by co-immunoprecipitation of these two proteins in extracts from a heterologous expression system and from a native tissue. The C-terminal three amino acids of Npn-1 (S-E-A-COOH), which is conserved from Xenopus to human, is responsible for interaction with the PDZ domain-containing C-terminal two-thirds of NIP. NIP as well as Npn-1 are broadly expressed in mice as assayed by Northern and Western analysis. Immunohistochemistry and in situ hybridization experiments revealed that NIP expression overlaps with that of Npn-1. NIP has been independently cloned as RGS-GAIP-interacting protein (GIPC), where it was identified by virtue of its interaction with the C terminus of RGS-GAIP and suggested to participate in clathrin-coated vesicular trafficking. We suggest that NIP and GIPC may participate in regulation of Npn-1-mediated signaling as a molecular adapter that couples Npn-1 to membrane trafficking machinery in the dynamic axon growth cone.
Howard Hughes Medical Institutes, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.
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D048868:Adaptor Proteins, Signal Transducing; D000595:Amino Acid Sequence / Q000235:genetics; D000818:Animals; D001369:Axons / Q000378:metabolism; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism / Q000502:physiology*; D002460:Cell Line; D002490:Central Nervous System / Q000378:metabolism; D003001:Cloning, Molecular; D006801:Humans; D051379:Mice; D008815:Mice, Inbred Strains; D008969:Molecular Sequence Data; D009411:Nerve Endings / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000235:genetics* / Q000502:physiology*; D009479:Neuropeptides / Q000235:genetics* / Q000378:metabolism / Q000502:physiology*; D039942:Neuropilin-1; D009833:Olfactory Pathways / Q000378:metabolism; D010525:Peripheral Nerves / Q000378:metabolism; D011233:Precipitin Tests; D017386:Sequence Homology, Amino Acid
D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; C492009:GIPC1 protein, human; C115271:Gipc1 protein, mouse; D009419:Nerve Tissue Proteins; D009479:Neuropeptides; D039942:Neuropilin-1