JUMONJI, a critical factor for cardiac development, functions as a transcriptional repressor. J Biol Chem 2003 Oct 24;278(43):42247-55
Date
08/02/2003Pubmed ID
12890668DOI
10.1074/jbc.M307386200Scopus ID
2-s2.0-0142242189 (requires institutional sign-in at Scopus site) 81 CitationsAbstract
JUMONJI (JMJ) is a nuclear factor that is critical for normal cardiovascular development, evidenced by the analysis of jmj homozygous mutant mice. However, the molecular function of JMJ remains to be elucidated. In the present study, we investigated whether JMJ is a transcriptional modulator. Reporter gene assays using the GAL4-DNA binding domain fused to JMJ and a reporter gene consisting of the GAL4 binding sites upstream of a luciferase reporter gene indicated that JMJ functions as a powerful transcriptional repressor. The DNA binding motif of JMJ was determined using CASTing experiments by incubating a random oligonucleotide library with the GST-JMJ fusion protein coupled to agarose beads. Among the selected binding oligonucleotides, the high affinity DNA binding sequences were identified by gel retardation assays. JMJ repressed expression of the reporter genes containing the high affinity JMJ binding sequences, indicating that JMJ is a DNA-binding transcriptional repressor. The domains for transcriptional repression, DNA binding, and nuclear localization signal were mapped by mutational analyses using reporter gene assays, gel retardation assays, and immunostaining experiments, respectively. The present data demonstrate for the first time that JMJ functions as a DNA-binding transcriptional repressor. Therefore, JMJ may play a critical role in transcription factor cascade to regulate expression of heart-specific genes and normal cardiac development.
Author List
Kim TG, Kraus JC, Chen J, Lee YAuthor
Jonathan C. Kraus MD Assistant Professor in the Orthopaedic Surgery department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AnimalsBase Sequence
Binding Sites
Dose-Response Relationship, Drug
Gene Expression Regulation
Genes, Reporter
Heart
Mice
Mutagenesis, Site-Directed
Nerve Tissue Proteins
Nuclear Localization Signals
Oligonucleotides
Polycomb Repressive Complex 2
Recombinant Fusion Proteins
Repressor Proteins
Transfection