A novel DNA binding protein that recognizes the methylated c-Myc binding motif.
We detected a novel nuclear protein, MMBP-3, that bound to the c-Myc binding motif (CACGTG) in which deoxycytidine in the CpG sequence was methylated. MMBP-3 was partially purified by chromatography on heparin-agarose and hydroxyapatite, followed by affinity adsorption to a matrix coupled to the methylated binding motif. Its binding to the methylated c-Myc binding motif was specific, although it also recognized the unmethylated motif weakly. MMBP-3 was further found to recognize only one of two differently hemimethylated forms of the double-stranded c-Myc binding motif. MMBP-3 activity was detected in proliferating C2C12 and C3H/10T1/2 cells, and down regulated when the growth of these cells was inhibited. We propose that MMBP-3 plays a role in regulating the c-Myc function by recognizing the methylation state of the c-Myc binding motif in a growth-dependent manner.
Institute for Protein Research, Osaka University.
I
I
Suetake
S
S
Tajima
A
A
Asano
D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000737:chemistry*; D008745:Methylation; D051379:Mice; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000737:chemistry*; D011485:Protein Binding; D016271:Proto-Oncogene Proteins c-myc / Q000737:chemistry*
D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D016271:Proto-Oncogene Proteins c-myc