TY - JOUR
T1 - ICF syndrome mutations cause a broad spectrum of biochemical defects in DNMT3B-mediated de novo DNA methylation
AU - Moarefi, Amir H.
AU - Chedin, Frederic
PY - 2011/6/24
Y1 - 2011/6/24
N2 - The DNMT3B de novo DNA methyltransferase (DNMT) plays a major role in establishing DNA methylation patterns in early mammalian development, but its catalytic mechanism remains poorly characterized. Here, we provide a comprehensive biochemical analysis of human DNMT3B function through the characterization of a series of site-directed DNMT3B variants associated with immunodeficiency, centromere instability, and facial anomalies (ICF) syndrome. Our data reveal several novel and important aspects of DNMT3B function. First, DNMT3B, unlike DNMT3A, requires a DNA cofactor in order to stably bind to S-adenosyl-l-methionine (SAM), suggesting that it proceeds according to an ordered catalytic scheme. Second, ICF mutations cause a broad spectrum of biochemical defects in DNMT3B function, including defects in homo-oligomerization, SAM binding, SAM utilization, and DNA binding. Third, all tested ICF mutations, including the A766P and R840Q variants, result in altered catalytic properties without interfering with DNMT3L-mediated stimulation; this indicates that DNMT3L is not involved in the pathogenesis of ICF syndrome. Finally, our study reveals a novel level of coupling between substrate binding, oligomerization, and catalysis that is likely conserved within the DNMT3 family of enzymes.
AB - The DNMT3B de novo DNA methyltransferase (DNMT) plays a major role in establishing DNA methylation patterns in early mammalian development, but its catalytic mechanism remains poorly characterized. Here, we provide a comprehensive biochemical analysis of human DNMT3B function through the characterization of a series of site-directed DNMT3B variants associated with immunodeficiency, centromere instability, and facial anomalies (ICF) syndrome. Our data reveal several novel and important aspects of DNMT3B function. First, DNMT3B, unlike DNMT3A, requires a DNA cofactor in order to stably bind to S-adenosyl-l-methionine (SAM), suggesting that it proceeds according to an ordered catalytic scheme. Second, ICF mutations cause a broad spectrum of biochemical defects in DNMT3B function, including defects in homo-oligomerization, SAM binding, SAM utilization, and DNA binding. Third, all tested ICF mutations, including the A766P and R840Q variants, result in altered catalytic properties without interfering with DNMT3L-mediated stimulation; this indicates that DNMT3L is not involved in the pathogenesis of ICF syndrome. Finally, our study reveals a novel level of coupling between substrate binding, oligomerization, and catalysis that is likely conserved within the DNMT3 family of enzymes.
KW - cytosine methylation
KW - DNA methyltransferase
KW - epigenetics
KW - oligomerization
KW - S-adenosyl-L- methionine
UR - http://www.scopus.com/inward/record.url?scp=79958071640&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=79958071640&partnerID=8YFLogxK
U2 - 10.1016/j.jmb.2011.04.050
DO - 10.1016/j.jmb.2011.04.050
M3 - Article
C2 - 21549127
AN - SCOPUS:79958071640
VL - 409
SP - 758
EP - 772
JO - Journal of Molecular Biology
JF - Journal of Molecular Biology
SN - 0022-2836
IS - 5
ER -