Location, location, location: Transcriptional activity and nuclear position
Dr. Mark Groudine (FHCRC) and colleagues report on their surprising characterization of changes in intranuclear organization during murine erythropoiesis. By assaying the nuclear position and expression level of the beta globin locus during various stages of erythropoiesis, the researchers found that beta globin expression begins at the nuclear periphery, and as red blood cells mature, the beta globin locus progressively moves away from the nuclear periphery, towards the interior. Furthermore, they found that efficient relocalization is dependent upon the locus control region (LCR). Contrary to the existing dogma, this finding demonstrates that gene transcription precedes relocalization – establishing the nuclear periphery as the new hot spot. Dr. Groudine emphasizes that "As recently shown in yeast, the nuclear periphery is a more complex compartment than thought. Clearly, determining the protein complexes associated with gene activation and repression at the nuclear periphery in mammalian cells is a high priority."
By John M. Grohol, Psy.D. on
21 Feb 2009
Published on PsychCentral.com. All rights reserved.
It is not because things are difficult that we do not dare; it is because we do not dare that they are difficult.