TY - JOUR
T1 - Analysis of tandem E-box motifs within human Complement receptor 2 (CR2/CD21) promoter reveals cell specific roles for RP58, E2A, USF and localized chromatin accessibility
AU - Cruickshank, Mark
AU - Dods, James
AU - Taylor, Rhonda
AU - Karimi, Mahdad
AU - Fenwick, Emily
AU - Quail, Elizabeth
AU - Rea, Alex
AU - Holers, V.M.
AU - Abraham, Lawrence
AU - Ulgiati, Daniela
PY - 2015/7
Y1 - 2015/7
N2 - ©2015 Elsevier Ltd. All rights reserved. Complement receptor 2 (CR2/CD21) plays an important role in the generation of normal B cell immune responses. As transcription appears to be the prime mechanism via which surface CR2/CD21 expression is controlled, understanding transcriptional regulation of this gene will have broader implications to B cell biology. Here we report opposing, cell-context specific control of CR2/CD21 promoter activity by tandem E-box elements, spaced 22 bp apart and within 70 bp of the transcription initiation site. We have identified E2A and USF transcription factors as binding to the distal and proximal E-box sites respectively in CR2-positive B-cells, at a site that is hypersensitive to restriction enzyme digestion compared to non-expressing K562 cells. However, additional unidentified proteins have also been found to bind these functionally important elements. By utilizing a proteomics approach we have identified a repressor protein, RP58, binding the distal E-box motif. Co-transfection experiments using RP58 overexpression constructs demonstrated a specific 10-fold repression of CR2/CD21 transcriptional activity mediated through the distal E-box repressor element. Taken together, our results indicate that repression of the CR2/CD21 promoter can occur through one of the E-box motifs via recruitment of RP58 and other factors to bring about a silenced chromatin context within CR2/CD21 non-expressing cells.
AB - ©2015 Elsevier Ltd. All rights reserved. Complement receptor 2 (CR2/CD21) plays an important role in the generation of normal B cell immune responses. As transcription appears to be the prime mechanism via which surface CR2/CD21 expression is controlled, understanding transcriptional regulation of this gene will have broader implications to B cell biology. Here we report opposing, cell-context specific control of CR2/CD21 promoter activity by tandem E-box elements, spaced 22 bp apart and within 70 bp of the transcription initiation site. We have identified E2A and USF transcription factors as binding to the distal and proximal E-box sites respectively in CR2-positive B-cells, at a site that is hypersensitive to restriction enzyme digestion compared to non-expressing K562 cells. However, additional unidentified proteins have also been found to bind these functionally important elements. By utilizing a proteomics approach we have identified a repressor protein, RP58, binding the distal E-box motif. Co-transfection experiments using RP58 overexpression constructs demonstrated a specific 10-fold repression of CR2/CD21 transcriptional activity mediated through the distal E-box repressor element. Taken together, our results indicate that repression of the CR2/CD21 promoter can occur through one of the E-box motifs via recruitment of RP58 and other factors to bring about a silenced chromatin context within CR2/CD21 non-expressing cells.
U2 - 10.1016/j.biocel.2015.03.016
DO - 10.1016/j.biocel.2015.03.016
M3 - Article
C2 - 25817480
VL - 64
SP - 107
EP - 119
JO - The International Journal of Biochemistry & Cell Biology
JF - The International Journal of Biochemistry & Cell Biology
SN - 1357-2725
ER -