Interplay of the E box, the cyclic AMP response element, and HTF4/HEB in transcriptional regulation of the neurospecific, neurotrophin-inducible vgf gene.
vgf is a neurotrophin response-specific, developmentally regulated gene that codes for a neurosecretory polypeptide. Its transcription in neuronal cells is selectively activated by the neurotrophins nerve growth factor (NGF), brain-derived neurotrophic factor, and neurotrophin 3, which induce survival and differentiation, and not by epidermal growth factor. We studied a short region of the rat vgf promoter which is essential for its regulated expression. A cyclic AMP response element (CRE) within this region is necessary for NGF induction of vgf transcription. Two sites upstream of CRE, an E box and a CCAAT sequence, bind nuclear protein complexes and are involved in transcriptional control. The E box has a dual role. It acts as an inhibitor in NIH 3T3 fibroblasts, together with a second E box located downstream, and as a stimulator in the NGF-responsive cell line PC12. By expression screening, we have isolated the cDNA for a basic helix-loop-helix transcription factor, a homolog of the HTF4/HEB E protein, that specifically binds the vgf promoter E box. The E protein was present in various cell lines, including PC12 cells, and was a component of a multiprotein nuclear complex that binds the promoter in vitro. The E box and CRE cooperate in binding to this complex, which may be an important determinant for neural cell-specific expression.
Di Rocco
G
G
Centro Acidi Nucleici CNR, Università La Sapienza, Rome, Italy.
Pennuto
M
M
Illi
B
B
Canu
N
N
Filocamo
G
G
Trani
E
E
Rinaldi
A M
AM
Possenti
R
R
Mandolesi
G
G
Sirinian
M I
MI
Jucker
R
R
Levi
A
A
Nasi
S
S
D016475:3T3 Cells; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D051792:Basic Helix-Loop-Helix Proteins; D003001:Cloning, Molecular; D000242:Cyclic AMP / Q000378:metabolism; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation / Q000235:genetics; D051379:Mice; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009414:Nerve Growth Factors / Q000494:pharmacology; D009479:Neuropeptides; D009687:Nuclear Proteins / Q000378:metabolism; D016716:PC12 Cells; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011506:Proteins / Q000235:genetics*; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017422:Sequence Analysis, DNA; D012689:Sequence Homology, Nucleic Acid; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic / Q000235:genetics*
D051792:Basic Helix-Loop-Helix Proteins; D000242:Cyclic AMP; D017362:Cyclic AMP Response Element-Binding Protein; D004247:DNA; D004268:DNA-Binding Proteins; D009414:Nerve Growth Factors; D009479:Neuropeptides; D009687:Nuclear Proteins; D011506:Proteins; D012333:RNA, Messenger; D014157:Transcription Factors; C489532:Tcf12 protein, mouse; C512697:Vgf protein, mouse; C062040:Vgf protein, rat; C104440:ubo8 protein, Papio hamadryas