Structural and functional conservation at the boundaries of the chicken β-globin domain

Authors

Noriko Saitoh, Cold Spring Harbor Laboratory, Cairns building, 1 Bungtown Road, Cold Spring Harbor, NY
Adam C. Bell, Instituto de Fisiologia Celular, Universidad Nacional Auton6ma de Mexico, Departamento de Genetica Molecular, Apartado Postal 70-242, Mexico, D.F.
Felix Recillas-Targa, Instituto de Fisiologia Celular, Universidad Nacional Auton6ma de Mexico, Departamento de Genetica Molecular, Apartado Postal 70-242, Mexico, D.F.
Adam G. West, Peale Science Center, Hope College, Holland, MI
Melanie A. Simpson, University of Nebraska - LincolnFollow
Michael Pikaart, Peale Science Center, Hope College, Holland, MI
Gary Felsenfeld

Document Type

Article

Date of this Version

October 2000

Comments

Published in The EMBO Journal Vol. 19 No. 10 pp.2315-2322, 2000. Copyright 2000. Used by permission.

Abstract

We show that the 3' boundary of the chicken β -globin locus bears striking structural similarities to the 5' boundary. In erythroid cells a clear transition in DNase I sensitivity of chromatin at the 3' end of the locus is observed, the location of this transition is marked by a constitutive DNase I hypersensitive site (HS), and DNA spanning this site has the enhancer-blocking capacity of an insulator. This HS contains a binding site for the transcription factor CTCF. As in the case of the 5' insulator, the CTCF site is both necessary and sufficient for the enhancer-blocking activity of the 3' boundary. The position of this insulator is consistent with our proposal that it may function to maintain the distinct regulatory programs of the globin genes and their closely appended 3' neighbor, an odorant receptor gene. We conclude that both boundaries of the chicken β-globin domain are capable of playing functionally similar roles and that the same protein is a necessary component of the molecular mechanism through which these boundaries are defined.