TY - JOUR
T1 - Genetic variation at a Yin-Yang 1 response site regulates the transcription of cyclin-dependent kinase inhibitor p18 INK4C transcript in lupus-prone mice
AU - Potula, Hari Hara S.K.
AU - Morel, Laurence
PY - 2012/5/15
Y1 - 2012/5/15
N2 - We have previously shown that a novel -74 C-to-T mutation in the promoter of the cyclin-dependent kinase inhibitor p18 Ink4c(p18) gene was associated with a reduced p18 expression in B cells from mice carrying the Sle2c1 lupus susceptibility locus. To determine the function of the -74 C/T single nucleotide polymorphism, we have characterized the proximal promoter of the mouse p18 gene. Functional analysis of the 5′ flanking region by sequential deletions revealed crucial elements between -300 and +1, confirming the in silico prediction that the 274 T allele created a novel Yin-Yang 1 (YY-1) binding site adjacent to an existing one common to both alleles. Moreover, we found that YY-1, E2F1, and Sp-1 can synergistically enhance the activity of the p18 promoter. Mutational inactivation revealed that YY-1 binding regulates the p18 activity in an allele-dependent fashion. EMSAs with splenic B cell extracts directly demonstrated that YY-1 binds to the p18 promoter with differences between the C and the T alleles. We also determined in vivo by chromatin immunoprecipitation that the T allele resulted in increased YY-1 and decreased Nrf-2 binding to the p18 promoter as compared with the C allele in B cells. Thus, YY-1 is a direct regulator of p18 gene expression in an allele-dependent fashion that is consistent with the lupus-associated T allele, inducing a lower p18 transcriptional activity by increasing YY-1 binding. These results establish the p18 -74 C/T mutation as the leading causal variant for the B1a cell expansion that characterizes the NZB and NZM2410 lupus-prone strains.
AB - We have previously shown that a novel -74 C-to-T mutation in the promoter of the cyclin-dependent kinase inhibitor p18 Ink4c(p18) gene was associated with a reduced p18 expression in B cells from mice carrying the Sle2c1 lupus susceptibility locus. To determine the function of the -74 C/T single nucleotide polymorphism, we have characterized the proximal promoter of the mouse p18 gene. Functional analysis of the 5′ flanking region by sequential deletions revealed crucial elements between -300 and +1, confirming the in silico prediction that the 274 T allele created a novel Yin-Yang 1 (YY-1) binding site adjacent to an existing one common to both alleles. Moreover, we found that YY-1, E2F1, and Sp-1 can synergistically enhance the activity of the p18 promoter. Mutational inactivation revealed that YY-1 binding regulates the p18 activity in an allele-dependent fashion. EMSAs with splenic B cell extracts directly demonstrated that YY-1 binds to the p18 promoter with differences between the C and the T alleles. We also determined in vivo by chromatin immunoprecipitation that the T allele resulted in increased YY-1 and decreased Nrf-2 binding to the p18 promoter as compared with the C allele in B cells. Thus, YY-1 is a direct regulator of p18 gene expression in an allele-dependent fashion that is consistent with the lupus-associated T allele, inducing a lower p18 transcriptional activity by increasing YY-1 binding. These results establish the p18 -74 C/T mutation as the leading causal variant for the B1a cell expansion that characterizes the NZB and NZM2410 lupus-prone strains.
UR - http://www.scopus.com/inward/record.url?scp=84861157368&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84861157368&partnerID=8YFLogxK
U2 - 10.4049/jimmunol.1101992
DO - 10.4049/jimmunol.1101992
M3 - Article
C2 - 22504641
AN - SCOPUS:84861157368
SN - 0022-1767
VL - 188
SP - 4992
EP - 5002
JO - Journal of Immunology
JF - Journal of Immunology
IS - 10
ER -