Abstract
The induction of neurite outgrowth by NGF is a transcription-dependent process in PC12 cells, but the transcription factors that mediate this process are not known. Here we show that the bHLH transcriptional repressor HES-1 is a mediator of this process. Inactivation of endogenous HES-1 by forced expression of a dominant-negative protein induces neurite outgrowth in the absence of NGF and increases response to NGF. In contrast, expression of additional wild-type HES-1 protein represses and delays response to NGF. Endogenous HES-1 DNA-binding activity is post-translationally inhibited during NGF signaling in vivo, and phosphorylation of PKC consensus sites in the HES-1 DNA-binding domain inhibits DNA binding by purified HES-1 in vitro. Mutation of these sites generates a constitutively active protein that strongly and persistently blocks response to NGF. These results suggest that post-translational inhibition of HES-1 is both essential for and partially mediates the induction of neurite outgrowth by NGF signaling.
Publication types
-
Research Support, Non-U.S. Gov't
-
Research Support, U.S. Gov't, P.H.S.
MeSH terms
-
Animals
-
Basic Helix-Loop-Helix Transcription Factors
-
Cell Differentiation / physiology
-
DNA / metabolism
-
Enzyme Inhibitors / pharmacology
-
Gene Expression
-
Growth Inhibitors / antagonists & inhibitors
-
Growth Inhibitors / genetics
-
Growth Inhibitors / metabolism*
-
Helix-Loop-Helix Motifs*
-
Homeodomain Proteins / antagonists & inhibitors
-
Homeodomain Proteins / genetics
-
Homeodomain Proteins / metabolism*
-
Indoles / pharmacology
-
Maleimides / pharmacology
-
Mice
-
Nerve Growth Factors / metabolism*
-
Neurites
-
Neurons / cytology*
-
Neurons / drug effects
-
PC12 Cells
-
Phosphorylation
-
Protein Biosynthesis
-
Protein Kinase C / metabolism
-
Rats
-
Repressor Proteins / antagonists & inhibitors
-
Repressor Proteins / genetics
-
Repressor Proteins / metabolism*
-
Serine / metabolism
-
Signal Transduction*
-
Tetradecanoylphorbol Acetate / pharmacology
-
Transcription Factor HES-1
Substances
-
Basic Helix-Loop-Helix Transcription Factors
-
Enzyme Inhibitors
-
Growth Inhibitors
-
Hes1 protein, mouse
-
Hes1 protein, rat
-
Homeodomain Proteins
-
Indoles
-
Maleimides
-
Nerve Growth Factors
-
Repressor Proteins
-
Transcription Factor HES-1
-
Serine
-
DNA
-
Protein Kinase C
-
bisindolylmaleimide
-
Tetradecanoylphorbol Acetate