Journal of Neuroscience, Vol 15, 6605-6618, Copyright © 1995 by Society for Neuroscience
A serine proteinase involved in contact mediated repulsion of retinal growth cones by DRG neurites
JL Baird and JA Raper
Department of Neurosciences, University of Pennsylvania School of Medicine, Philadelphia 19104, USA.
Cultured retinal ganglion cell growth cones avoid neurites extending from
PNS explants. Here we characterize a growth cone collapsing activity in
detergent extracts of newborn calf adrenal plasma membranes that has
characteristics expected for an avoidance cue on peripheral neurites. This
adrenal derived activity induces the rapid and reversible collapse of
retinal growth cones grown on either of two distinct adhesion substrata,
mouse laminin or the chick cell surface axonal glycoprotein G4/NgCAM. The
collapsing activity is inhibited by several different types of serine
proteinase inhibitors, including the irreversible inhibitor PPACK
(D-phenylalanyl-prolyl-arginine chloromethyl ketone). The activity is not
inhibited by the specific thrombin inhibitor, hirudin. We have named the
adrenal derived collapsing activity erase. PPACK blocks the collapse of
temporal retinal growth cones on contact with DRG neurites, but does not
block the collapse of the same growth cones on contact with nasal retinal
neurites. These results support the hypothesis that a serine proteinase on
peripheral axons serves as an avoidance cue which induces contact mediated
collapse of retinal growth cones.