PMID- 10454587
OWN - NLM
STAT- MEDLINE
DCOM- 19990910
LR  - 20190508
IS  - 0270-7306 (Print)
IS  - 0270-7306 (Linking)
VI  - 19
IP  - 9
DP  - 1999 Sep
TI  - Methylation-mediated transcriptional silencing in euchromatin by methyl-CpG
      binding protein MBD1 isoforms.
PG  - 6415-26
AB  - DNA methylation of promoter-associated CpG islands is involved in the
      transcriptional repression of vertebrate genes. To investigate the mechanisms
      underlying gene inactivation by DNA methylation, we characterized a human MBD1
      protein, one of the components of MeCP1, which possesses a methyl-CpG binding
      domain (MBD) and cysteine-rich (CXXC) domains. Four novel MBD1 isoforms (MBD1v1, 
      MBD1v2, MBD1v3, and MBD1v4) were identified by the reverse transcription-PCR
      method. We found that these transcripts were alternatively spliced in the region 
      of CXXC domains and the C terminus. Green fluorescent protein-fused MBD1 was
      localized to multiple foci on the human genome, mostly in the euchromatin
      regions, and particularly concentrated in the pericentromeric region of
      chromosome 1. Both the MBD sequence and genome methylation were required for
      proper localization of the MBD1 protein. We further investigated whether MBD1
      isoforms are responsible for transcriptional repression of human genes. A
      bacterially expressed MBD1 protein bound preferentially to methylated DNA
      fragments containing CpG islands from the tumor suppressor genes p16, VHL, and
      E-cadherin and from an imprinted SNRPN gene. All MBD1 isoforms inhibited promoter
      activities of these genes via methylation. Interestingly, MBD1 isoforms v1 and v2
      containing three CXXC domains also suppressed unmethylated promoter activities in
      mammalian cells. These effects were further manifested in Drosophila melanogaster
      cells, which lack genome methylation. Sp1-activated transcription of methylated
      p16 and SNRPN promoters was inhibited by all of the MBD1 isoforms, whereas the
      isoforms v1 and v2 reduced Sp1-activated transcription from unmethylated
      promoters as well. These findings suggested that the MBD1 isoforms have different
      roles in methylation-mediated transcriptional silencing in euchromatin.
FAU - Fujita, N
AU  - Fujita N
AD  - Department of Tumor Genetics and Biology, Kumamoto University School of Medicine,
      Kumamoto 860-0811, Japan.
FAU - Takebayashi, S
AU  - Takebayashi S
FAU - Okumura, K
AU  - Okumura K
FAU - Kudo, S
AU  - Kudo S
FAU - Chiba, T
AU  - Chiba T
FAU - Saya, H
AU  - Saya H
FAU - Nakao, M
AU  - Nakao M
LA  - eng
SI  - GENBANK/AF078830
SI  - GENBANK/AF078831
SI  - GENBANK/AF078832
SI  - GENBANK/AF078833
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - Mol Cell Biol
JT  - Molecular and cellular biology
JID - 8109087
RN  - 0 (Chromatin)
RN  - 0 (DNA Primers)
RN  - 0 (DNA-Binding Proteins)
RN  - 0 (Euchromatin)
RN  - 0 (MeCP1 histone deacetylase complex, human)
RN  - 0 (Protein Isoforms)
RN  - EC 3.5.1.98 (Histone Deacetylases)
SB  - IM
MH  - Alternative Splicing
MH  - Amino Acid Sequence
MH  - Animals
MH  - Base Sequence
MH  - Binding Sites/genetics
MH  - COS Cells
MH  - Cell Line
MH  - Cell Nucleus/metabolism
MH  - Chromatin/*genetics/*metabolism
MH  - CpG Islands
MH  - *DNA Methylation
MH  - DNA Primers/genetics
MH  - DNA-Binding Proteins/genetics/*metabolism
MH  - Drosophila melanogaster/genetics/metabolism
MH  - Euchromatin
MH  - HeLa Cells
MH  - *Histone Deacetylases
MH  - Humans
MH  - Molecular Sequence Data
MH  - Protein Isoforms/genetics/metabolism
MH  - Transcription, Genetic
PMC - PMC84611
EDAT- 1999/08/24 00:00
MHDA- 1999/08/24 00:01
CRDT- 1999/08/24 00:00
PHST- 1999/08/24 00:00 [pubmed]
PHST- 1999/08/24 00:01 [medline]
PHST- 1999/08/24 00:00 [entrez]
AID - 10.1128/mcb.19.9.6415 [doi]
PST - ppublish
SO  - Mol Cell Biol. 1999 Sep;19(9):6415-26. doi: 10.1128/mcb.19.9.6415.