Characterization of the biological functions of a transcription factor, c-myc intron binding protein 1 (MIBP1).
The c-myc intron binding protein 1 (MIBP1) is a gigantic zinc finger protein comprising 2,437 amino acids and belonging to the MHC binding protein (MBP) family. MIBP1 is suggested to be a transcription factor involved in various biological functions. We show here that MIBP1 represses c-myc transcription from the major promoter, P2. Screening by the yeast two-hybrid system revealed that the MIBP1 protein interacts with the Ski-interacting protein (SKIP). In vitro pull-down assays and in vivo co-immunoprecipitation experiments confirmed this interaction. The acidic region of MIBP1 was found to be the site of interaction with the N-terminal half of SKIP. In situ hybridization analysis using developing rat embryos revealed that the MIBP1 mRNA is highly expressed in post-mitotic neurons, but the expression in immature neuroepithelium is low. The expression of MIBP1 in adult rat brain is also predominantly in neuronal cells, indicating that MIBP1 is involved in the physiology of mature neuronal cells.
Fukuda
Shinji
S
Division of Genome Analysis, Research Center for Genetic Information, Medical Institute of Bioregulation, Kyushu University, Fukuoka 812-8582, Japan.
Yamasaki
Yuki
Y
Iwaki
Toru
T
Kawasaki
Hiroaki
H
Akieda
Shizuka
S
Fukuchi
Naruhiko
N
Tahira
Tomoko
T
Hayashi
Kenshi
K
D000595:Amino Acid Sequence; D000818:Animals; D001921:Brain / Q000378:metabolism*; D019556:COS Cells / Q000378:metabolism; D002352:Carrier Proteins / Q000378:metabolism; D002522:Chlorocebus aethiops; D004268:DNA-Binding Proteins / Q000235:genetics / Q000502:physiology*; D004622:Embryo, Mammalian / Q000378:metabolism*; D006801:Humans; D017403:In Situ Hybridization; D008969:Molecular Sequence Data; D009474:Neurons / Q000166:cytology / Q000378:metabolism; D009687:Nuclear Proteins / Q000378:metabolism*; D056918:Nuclear Receptor Coactivators; D016271:Proto-Oncogene Proteins c-myc / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017386:Sequence Homology, Amino Acid; D014018:Tissue Distribution; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D020798:Two-Hybrid System Techniques
D002352:Carrier Proteins; D004268:DNA-Binding Proteins; C091698:Hivep2 protein, rat; D009687:Nuclear Proteins; D056918:Nuclear Receptor Coactivators; D016271:Proto-Oncogene Proteins c-myc; D012333:RNA, Messenger; C581694:SKIP protein, rat; C111791:SNW1 protein, human; D014157:Transcription Factors; C077171:HIVEP2 protein, human