The Beta-Globin Locus

Published on October 1, 2007 Updated on November 4, 2014   35 min

Other Talks in the Series: Epigenetics, Chromatin, Transcription and Cancer

Other Talks in the Series: Eukaryotic Gene Regulation

This is Ann Dean I'm an investigator at the National Institutes of Health in the National Institute of Diabetes and Digestive and Kidney Diseases. The hemoglobin genes are the subject of my research, in particular, the regulation of these genes at the level of chromatin and at the level of nuclear folding of chromosomes.
The beta globin locus has long served as a major paradigm for studies of eukaryotic gene regulation and transcription. In mammals, the alpha and beta globin loci encode the polypeptides that form the heteromeric hemoglobin protein molecule. Hemoglobin is a 64-kilodalton protein consisting of four polypeptide chains. Two so-called beta-like globin chains and two alpha-like globin chains. In each tetramer, the four globin chains are held together by noncovalent attractions. The human hemoglobin tetramer is depicted in the drawing. The alpha2 beta2 tetramer is called hemoglobin A, or HbA, and is the predominant hemoglobin in adults. Each chain contains a heme group, labeled in the picture, which coordinates an iron atom. This moiety gives hemoglobin its characteristic red color. Hemoglobin transports oxygen and CO2 in the bloodstream.