Journal of Neuroscience, Vol 6, 61-67, Copyright © 1986 by Society for Neuroscience
NIF (neurite-inducing factor): a novel peptide inducing neurite formation in PC12 cells
JA Wagner
Neurite-inducing factor (NIF) is a novel protein that has been partially
purified from mouse submaxillary glands. NIF induces neurite formation in
PC12 pheochromocytoma cells, and the NIF-induced neurites are
indistinguishable from NGF-induced neurites in both their morphology and
the time course of their formation. Neurite-inducing activity can be
recovered at a position corresponding to a molecular weight of 20,000 Da
after fractionation of partially purified preparations via SDS-PAGE.
Partially purified preparations of NIF are about half as potent as pure
beta NGF, and since the neurite-inducing activity does not correspond to
any of the major proteins in this fraction, specific activity of purified
NIF will probably be significantly greater than the 60 ng/ml found for our
partially purified material. NIF is distinct from beta NGF by four
criteria: (1) antibodies to beta NGF can block the activity of beta NGF,
but not the activity of NIF; (2) beta NGF can induce ornithine
decarboxylase (ODC) in PC12 cells at concentrations significantly below
those required to induce neurites, while NIF induces ODC only at
concentrations greatly in excess of those required to induce neurite
formation; (3) by the criterion of SDS-PAGE, there is insufficient beta NGF
in our partially purified preparations of NIF to explain the biological
activity of this fraction; and (4) the biological activity of NIF has a
molecular weight (20,000 Da) that is distinct from beta NGF (13,000 Da). We
conclude that NIF is probably a novel peptide that is very active in
promoting morphological differentiation.(ABSTRACT TRUNCATED AT 250 WORDS)