Identification of Protein‐Interacting Partners of USF2 in Erythroid Cells

Abstract

Adult hemoglobin, comprised of α and β‐globin protein chains, is the major constituent of red blood cells that functions to transport oxygen around the body. Mutations of these genes lead to hemoglobinopathies such as sickle cell anemia. It has been previously demonstrated that the Upstream Stimulatory Factor (USF) activates globin gene expression. USF, composed of USF1 and USF2, is a ubiquitously expressed protein and likely interacts with erythroid‐specific activities to regulate globin gene expression. The goal of this project is to identify protein‐interacting partners of USF in order to derive a molecular pathway of adult β‐globin activation.Using the murine erythroleukemia (MEL) and the human erythroleukemia (K562) cell lines as models for erythroid globin expression, we have successfully expressed a biotin‐flag‐tagged USF protein in these cells in an inducible manner. USF interacting proteins are identified by tandem affinity purification followed by mass spectrometry analyses. Here, we present data on the novel identification and characterization of the multiple protein‐interacting partners of USF. This knowledge provides insight into developing novel therapies for hemoglobinopathies.