Journal of Neuroscience, Vol 5, 3039-3046, Copyright © 1985 by Society for Neuroscience
Neurofilament protein abnormalities in PC12 cells: comparison with neurofilament proteins of normal cultured rat sympathetic neurons
VM Lee
The studies described here characterize abnormalities in the expression of
neurofilament (NF) proteins in a clonal rat pheochromocytoma (PC12) cell
line as compared with normal NF proteins in cultured rat sympathetic
neurons (RSNs). Cytoskeletal extracts from PC12 cells grown in the presence
(PC12+ cells) or absence (PC12- cells) of nerve growth factor (NGF) and
from RSNs grown in the presence of NGF were analyzed in nitrocellulose
replicas of one- and two-dimensional polyacrylamide gels by the immunoblot
method using monoclonal antibodies and antiserum to individual NF subunits.
RSNs failed to express the high molecular weight NF subunit (NF200) for the
first 10 days in culture although both lower molecular weight NF subunits
(NF68 and NF150) were expressed by these cells. At later times in culture,
all three NF subunits were present in immunoblots of RSNs. The immunoblot
profile of NF proteins in PC12- cells was identical to that of RSNs grown
in culture for up to 10 days. Growth of PC12 cells in NGF for up to 3 weeks
did not alter this immunoblot profile except that no immunoband
corresponding in NF200 was seen and the immunobands corresponding to NF68
and NF150 became more prominent. These data suggest that abnormalities in
NF protein expression in PC12 cells are due to a paucity of NF200 or to the
presence of immunochemically altered NF200. PC12 cells are an attractive
model system for probing abnormal NF metabolism.