Date of Award

Summer 6-17-2022

Degree Type

Thesis

Degree Name

Master of Science

Department

Biological, Geological & Environmental Sciences

First Advisor

Gnanapragasam, M N

Second Advisor

Weyman, Crystal

Third Advisor

Shukla, Girish

Subject Headings

Biology, Cellular Biology

Abstract

Erythrocytes are primarily comprised of the oxygen carrying protein hemoglobin. Genetic mutations causing defects in the proper synthesis of hemoglobin result in various anemias. It is during the last phases of terminal erythroid differentiation that hemoglobin levels rise, making it a focus for therapeutic research. Fetal hemoglobin is comprised of ⍺-globin and gamma globin, then after a change in gene expression called hemoglobin switching which takes place after birth, adult hemoglobin is comprised of ⍺-globin and beta globin. We investigated hemoglobin switching and erythroid terminal differentiation by focusing on the master erythroid transcription factor Erythroid Krüppel-like Factor (EKLF). Data led to identifying two novel EKLF targets. The first, Pumilio 1 (PUM1), is a protein that is known as a post transcriptional repressor and not been studied in erythrocytes until now. Our work indicates that PUM1 does indeed work as a post transcriptional repressor of 𝛾-globin in adult cells. Data also shows that if PUM1 levels are lowered that 𝛾-globin levels rise significantly without altering β-globin levels or stalling progression through erythroid terminal differentiation. Together, this data shows that PUM1 mediated post-transcriptional regulations has a significant role in hemoglobin switching and could serve as an excellent therapeutic target since the induction of 𝛾-globin has been shown to ameliorate symptoms of hemoglobinopathies. The second EKLF target investigated is Inner Centromere Protein (INCENP). This protein has a major role in lining up chromosomes and microtubules for successful cytokinesis. This preliminary investigation showed that there is an increase in ploidy when INCENP levels are lower in erythroid cells.

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