MM-1, a novel c-Myc-associating protein that represses transcriptional activity of c-Myc.
We have isolated the cDNA encoding a novel c-Myc-binding protein, MM-1, by the yeast two-hybrid screening of a human HeLa cell cDNA library. The protein deduced from the cDNA comprises 167 amino acids and was localized in the nucleus of introduced COS-I cells. The MM-1 mRNA was highly expressed in human pancreas and skeletal muscle and moderately in other tissues. As for the c-Myc binding, glutathione S-transferase MM-1 expressed in Escherichia coli bound in vitro to c-Myc translated in reticulocyte lysate, and almost whole, the MM-1 molecule was necessary for the binding in the yeast two-hybrid system. The mammalian two-hybrid assays in hamster CHO cells revealed that MM-1 interacts in vivo with the N-terminal domain covering the myc box 2, a transcription-activating domain, of c-Myc. Furthermore, MM-1 repressed the activation of E-box-dependent transcription by c-Myc.
Mori
K
K
Graduate School of Pharmaceutical Sciences, Hokkaido University, Kita-ku, Sapporo 060, Japan.
Maeda
Y
Y
Kitaura
H
H
Taira
T
T
Iguchi-Ariga
S M
SM
Ariga
H
H
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D016466:CHO Cells; D019556:COS Cells; D003001:Cloning, Molecular; D006224:Cricetinae; D017931:DNA Primers; D018076:DNA, Complementary; D019084:Fluorescent Antibody Technique, Indirect; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D016271:Proto-Oncogene Proteins c-myc / Q000037:antagonists & inhibitors* / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics; D014158:Transcription, Genetic
D017931:DNA Primers; D018076:DNA, Complementary; C115636:PFDN5 protein, human; D016271:Proto-Oncogene Proteins c-myc; D012097:Repressor Proteins