Growth cone neuropilin-1 mediates collapsin-1/Sema III facilitation of antero- and retrograde axoplasmic transport.
Collapsin-1/Sema III, a member of the semaphorin family, has been implicated in axonal pathfinding as a repulsive guidance cue. Cellular and molecular mechanisms by which collapsin-1 exerts its action are not fully understood. Collapsin-1 induces growth cone collapse via a pathway which may include neuropilin-1, a cellsurface collapsin-1 binding protein, as well as intracellular CRMP-62 and heterotrimeric G proteins. We previously identified a second action of collapsin-1, the facilitation of antero- and retrograde axoplasmic transport. This response occurs via a mechanism distinct from that causing growth cone collapse. To investigate the possible involvement of neuropilin-1 in the action of collapsin-1 on axoplasmic transport, we produced a soluble neuropilin-1 (sNP-1) lacking the transmembrane and intracellular region. sNP-1 progressively displaced the dose-response curve for collapsin-1 to induce growth cone collapse to higher concentrations. sNP-1 also inhibited collapsin-1-induced augmentation of both antero- and retrograde axoplasmic transport. Furthermore, an anti-neuropilin-1 antibody blocked the collapsin-induced axoplasmic transport. These results together indicate that neuropilin-1 mediates collapsin-1 action on axoplasmic transport. To visualize collapsin-1 binding to endogenous neuropilin-1, we used a truncated collapsin-1-alkaline phosphatase fusion protein (CAP-4). CAP-4 stains the growth cone, neurite, and cell body. However, local application of collapsin-1 to growth cone but to neither neurite nor cell body promotes axoplasmic transport. Thus, growth cone NP-1 mediates the facilitatory action of collapsin-1 on antero- and retrograde axoplasmic transport.
Goshima
Y
Y
Department of Pharmacology, Yokohama City University School of Medicine, Yokohama, Japan.
Hori
H
H
Sasaki
Y
Y
Yang
T
T
Kagoshima-Maezono
M
M
Li
C
C
Takenaka
T
T
Nakamura
F
F
Takahashi
T
T
Strittmatter
S M
SM
Misu
Y
Y
Kawakami
T
T
D000469:Alkaline Phosphatase / Q000235:genetics; D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D001370:Axonal Transport / Q000502:physiology*; D002478:Cells, Cultured; D002642:Chick Embryo; D005727:Ganglia, Spinal / Q000166:cytology; D015870:Gene Expression / Q000502:physiology; D006023:Glycoproteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D020439:Growth Cones / Q000737:chemistry / Q000378:metabolism*; D051379:Mice; D018715:Microscopy, Video; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D039942:Neuropilin-1; D010957:Plasmids; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D040121:Semaphorin-3A; D012995:Solubility; D014162:Transfection
D000906:Antibodies; D006023:Glycoproteins; D009419:Nerve Tissue Proteins; D011994:Recombinant Proteins; D040121:Semaphorin-3A; D039942:Neuropilin-1; D000469:Alkaline Phosphatase