CTCF is conserved from Drosophila to humans and confers enhancer blocking of the Fab-8 insulator.
Eukaryotic transcriptional regulation often involves regulatory elements separated from the cognate genes by long distances, whereas appropriately positioned insulator or enhancer-blocking elements shield promoters from illegitimate enhancer action. Four proteins have been identified in Drosophila mediating enhancer blocking-Su(Hw), Zw5, BEAF32 and GAGA factor. In vertebrates, the single protein CTCF, with 11 highly conserved zinc fingers, confers enhancer blocking in all known chromatin insulators. Here, we characterize an orthologous CTCF factor in Drosophila with a similar domain structure, binding site specificity and transcriptional repression activity as in vertebrates. In addition, we demonstrate that one of the insulators (Fab-8) in the Drosophila Abdominal-B locus mediates enhancer blocking by dCTCF. Therefore, the enhancer-blocking protein CTCF and, most probably, the mechanism of enhancer blocking mediated by this remarkably versatile factor are conserved from Drosophila to humans.
Moon
Hanlim
H
Section of Molecular Pathology, Laboratory of Immunopathology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland 20852, USA.
Filippova
Galina
G
Loukinov
Dmitry
D
Pugacheva
Elena
E
Chen
Qi
Q
Smith
Sheryl T
ST
Munhall
Adam
A
Grewe
Britta
B
Bartkuhn
Marek
M
Arnold
Rüdiger
R
Burke
Les J
LJ
Renkawitz-Pohl
Renate
R
Ohlsson
Rolf
R
Zhou
Jumin
J
Renkawitz
Rainer
R
Lobanenkov
Victor
V
D000595:Amino Acid Sequence; D000818:Animals; D000076246:CCCTC-Binding Factor; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D004330:Drosophila / Q000235:genetics* / Q000378:metabolism; D029721:Drosophila Proteins / Q000235:genetics* / Q000378:metabolism; D004742:Enhancer Elements, Genetic; D005786:Gene Expression Regulation / Q000502:physiology; D018398:Homeodomain Proteins / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D038101:Insulator Elements; D008969:Molecular Sequence Data; D012097:Repressor Proteins / Q000235:genetics* / Q000378:metabolism
C062393:Abd-B proteins, Drosophila; D000076246:CCCTC-Binding Factor; C000619697:CTCF protein, human; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D018398:Homeodomain Proteins; D012097:Repressor Proteins