Human CREM ELISA Matched Antibody Pair

Using a radiation-hybrid cell, El I, produced by the fusion of Hepa-1c1c7 and X-ray irradiated HepG2 cells, we located the omeprazole (OP) responsive region on Chromosome 10p. The cDNA of 12 genes expressed in Ell cells were cloned from HepG2 mRNA by RT-PCR. The cDNA was transfected into Hepa-1c1c7 cells to check the increased expression of Cyp1a1 by reporter gene (luciferase) assay. Finally, one gene (tau CREM: cAMP responsive element modulator, T-isoform) was identified as a candidate gene for the gene responsive to OP. The regulatory sequence of Cyp1a1 in response to tau CREM transfection was identified in one region (-60 to -52 bp relative to the transcription start site), which was the basic transcription element (BTE). Electromobility shift assay with the BTE sequence showed an increase in the band intensity when the cells were treated with OP. Decreased level of endogenous CREM by siRNA transfection inhibited the induction of CYP1A1-mRNA in HepG2 cells by OP. (c) 2008 Elsevier Inc. All rights reserved.

Systemic lupus erythematosus (SLE) is a complex autoimmune disease with numerous abnormalities recorded at the cellular, molecular, and genetic level. Expression of the basic leucine zipper transcription factor cAMP-responsive element modulator (CREM)alpha was reported to be abnormally increased in T cells from SLE patients. CREM alpha suppresses IL-2 and T cell receptor xi chain gene transcription by direct binding to the respective promoters. Here, we show that increased CREM expression is the result of enhanced promoter activity. DNA binding analyses reveal direct binding of transcription factor specificity protein-1 (SP-1) to the CREM promoter resulting in enhanced transcriptional activity and increased CREM expression. Protein phosphatase 2A is known to activate SP-1 through dephosphorylation at its serine residue 59. Our results show that nuclei from SLE T cells contain lower levels of Ser(59)-phosphorylated SP-1 protein and a stronger SP-1 binding to the CREM promoter. We conclude that protein phosphatase 2A accounts for enhanced SP-1 dephosphorylation at Ser(59) in SLE T cells. More importantly, CREM promoter activity mirrors reliably disease activity in SLE patients, underscoring its potential role as a biomarker for the prediction of flares in SLE patients.