Regulated expression of the beta-globin gene locus in synthetic nuclei.
Regulated gene expression within a complex chromosomal locus requires multiple nuclear processes. We have analyzed the transcriptional properties of the cloned chick beta-globin gene family when assembled into synthetic nuclei made by use of Xenopus egg extracts. Assembly in an erythroid protein environment correctly recapitulates tissue-specific chromatin structure and long-range promoter-enhancer interaction within the chromosomal locus, resulting in beta-globin gene activation. Nucleosome-repressed beta-globin templates can be transcriptionally activated by double-stranded DNA replication in the presence of staged erythroid proteins by remodeling of the chromatin structure within the promoter region and establishment of distal promoter-enhancer communication. The programmed transcriptional state of a gene, as encoded by its chromatin structure and long-range promoter-enhancer interactions, is stable to nuclear decondensation and DNA replication unless active remodeling occurs in the presence of specific DNA-binding proteins.
Barton
M C
MC
Regulatory Biology Laboratory, Salk Institute for Biological Studies, La Jolla, California 92037.
Emerson
B M
BM
D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism*; D002645:Chickens; D002843:Chromatin / Q000378:metabolism; D003001:Cloning, Molecular; D003360:Cosmids; D004261:DNA Replication; D004742:Enhancer Elements, Genetic; D005260:Female; D005786:Gene Expression Regulation; D005914:Globins / Q000235:genetics*; D066298:In Vitro Techniques; D019384:Nucleic Acid Synthesis Inhibitors; D010063:Ovum / Q000378:metabolism; D015533:Transcriptional Activation; D014981:Xenopus
D002843:Chromatin; D019384:Nucleic Acid Synthesis Inhibitors; D005914:Globins