Hemoglobin switching: new insights.

During the past year, many interesting advances have been made regarding molecular mechanisms controlling beta-like globin gene switching. Throughout the beta locus, -acting elements exist that are dynamically bound by trans-acting proteins, including transcription factors, coactivators, repressors, and chromatin modifiers. Characterization of transcription factors, their interaction with one another, and an ever-increasing role for chromatin structure in gene expression have enhanced understanding of the mechanism of globin gene switching. The studies reviewed here contribute new insights on the interplay between -acting elements, transcription factors, and chromatin modifiers that underlie globin gene switching during development.