ROLES OF KRÜPPEL LIKE FACTORS KLF1, KLF2, AND KLF4 IN EMBRYONIC BETA-GLOBIN GENE EXPRESSION

Abstract

ROLES OF KRUPPEL LIKE FACTORS KLF1, KLF2, AND KLF4 IN EMBRYONIC BETA-GLOBIN GENE EXPRESSION By: Yousef Nassir Alhashem A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science at Virginia Commonwealth University Virginia Commonwealth University, 2009 Director: Joyce A. Lloyd, Ph.D. Professor Department of Human and Molecular Biology Kruppel like factors (KLFs) are a family of 17 proteins whose main function is gene regulation by binding to DNA elements in the promoters of various genes. KLF transcription factors recognize CACCC-elements and act as activators or repressors of the gene expression. Among the 17 family members, KLF1, KLF2, and KLF4 share high homology to each other. KLF1 is the founding member of the family and is an erythroidspecific protein. KLF2 is expressed in erythroid, endothelial, and other cells. KLF4 is expressed in endothelial, smooth muscle, and other cells. In this thesis, the functions of these KLFs were reviewed in the context of subjects related to erythropoiesis and cardiovascular development. A mouse model lacking KLF1, KLF2, and KLF4 was used to investigate whether these genes have overlapping functions in regulating the