EGR2 mutations in inherited neuropathies dominant-negatively inhibit myelin gene expression.
The identification of EGR2 mutations in patients with neuropathies and the phenotype Egr2/Krox20(-/-) have demonstrated that the Egr2 transcription factor is critical for peripheral nerve myelination. However, the mechanism by which these mutations cause disease remains unclear, as most patients present with disease in the heterozygous state, whereas Egr2(+/-) mice are phenotypically normal. To understand the effect of aberrant Egr2 activity on Schwann cell gene expression, we performed microarray expression profiling to identify genes regulated by Egr2 in Schwann cells. These include genes encoding myelin proteins and enzymes required for synthesis of normal myelin lipids. Using these newly identified targets, we have shown that neuropathy-associated EGR2 mutants dominant-negatively inhibit wild-type Egr2-mediated expression of essential myelin genes to levels sufficiently low to result in the abnormal myelination observed in these patients.
Nagarajan
R
R
Department of Pathology, Washington University School of Medicine, 660 South Euclid Avenue, Box 8118, St. Louis, MO 63110, USA.
Svaren
J
J
Le
N
N
Araki
T
T
Watson
M
M
Milbrandt
J
J
D000818:Animals; D000831:Animals, Newborn; D002460:Cell Line; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism*; D051767:Early Growth Response Protein 2; D005786:Gene Expression Regulation; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins; D006801:Humans; D017874:Immediate-Early Proteins / Q000235:genetics; D008164:Luminescent Proteins / Q000235:genetics; D008297:Male; D009185:Myelin Proteins / Q000235:genetics*; D009186:Myelin Sheath / Q000235:genetics / Q000502:physiology; D009409:Nerve Crush; D009419:Nerve Tissue Proteins / Q000235:genetics*; D020411:Oligonucleotide Array Sequence Analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012583:Schwann Cells / Q000166:cytology / Q000502:physiology*; D012584:Sciatic Nerve / Q000166:cytology / Q000502:physiology*; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism*; D014162:Transfection
D004268:DNA-Binding Proteins; C497326:EGR2 protein, human; D051767:Early Growth Response Protein 2; C497328:Egr2 protein, rat; D017874:Immediate-Early Proteins; D008164:Luminescent Proteins; D009185:Myelin Proteins; D009419:Nerve Tissue Proteins; D014157:Transcription Factors; D049452:Green Fluorescent Proteins