Biochemistry, Biophysics, and Structural Biology Commons^™

Insights Into De Novo Fes-Cluster Biogenesis Via The Eukaryotic Fes-Cluster (Isc) Pathway In Vitro, Stephen Paul Dzul

Wayne State University Dissertations

Fe-S clusters are iron-containing cofactors utilized by numerous proteins within several biological pathways essential to life. In eukaryotes, the primary pathway for Fe-S cluster production is the iron-sulfur cluster (ISC) pathway. The eukaryotic ISC pathway, localized primarily within the mitochondria, has been best characterized within Saccharomyces cerevisiae. In yeast, de novo Fe-S cluster formation is accomplished through coordinated assembly of the substrates iron and sulfur on the primary scaffold assembly protein “Isu1”. The sulfur used for cluster assembly is provided by the cysteine desulfurase “Nfs1”, a protein that works in union with its accessory protein “Isd11”. Frataxin “Yfh1” helps direct …

Characterization Of The Yeast Cysteine Desulfurase Complex Within The Mitochondrial Fe-S Cluster Biogenesis, Dulmini Pabasara Barupala

Wayne State University Dissertations

Disrupted iron homeostasis within the human body materializes as various disorders. Pathophysiology of many of them relates to iron induced oxidative damage to key cellular components caused by iron accumulation within the tissues. Pertaining to the growing occurrence, cost of patient care and devastating burden associated with these diseases, the call for understanding the role of iron homeostasis within these disorders becomes inevitable. Being an abundant iron containing cofactor, the role of Fe-S clusters in cellular iron homeostasis is indisputable in the case of Friedreich’s ataxia, a disease caused by a deficiency in the protein frataxin that is indispensable during …

A Protective Role Of Autophagy In A Drosophila Model Of Friedreich's Ataxia (Frda), Luan Wang

Wayne State University Dissertations

Friedreich’s ataxia (FRDA) is an inherited autosomal recessive neurodegenerative disease. It affects 1 in every 50,000 people in central Europe and North America. FRDA is caused by deficiency of Frataxin, an essential mitochondrial iron chaperone protein, and the associated oxidative stress damages. Autophagy, a housekeeping process responsible for the bulk degradation and turnover of long half-life proteins and organelles, is featured by the formation of double-membrane vacuoles and lysosomal degradation. Previous researches indicate that Danon’s disease, the inherited neural disorder disease that shares similar symptoms with FRDA, is due to the malfunction of autophagy. Based on this, we raise the …

Characterization Of Initial Iron Binding Location And The Structure/Iron Binding Site On S.Cerevisiae Isu And On D.Melanogaster Frataxin, Andria V. Rodrigues

Wayne State University Dissertations

Iron-induced free radical damage has been implicated in the pathology of diseases of iron overload such as Friedreich's Ataxia, a genetic disorder characterized by an accumulation of iron in actively metabolizing tissues ultimately leading to cardio- and neuro- degeneration and cell death. It is caused by an inability to synthesize the mitochondrial protein, frataxin. Frataxin has been shown by numerous groups to be a part of the iron-sulfur cluster (ISC) multicomplex, where it functions in the capacity of a potential iron provider and an allosteric modulator of both the cysteine desulfurase and scaffold protein ISU. My research has been focused …

Molecular Details Of The Mitochondrial Iron Sulfur Cluster Assembly Pathway, Swati Rawat

Wayne State University Dissertations

MOLECULAR DETAILS OF THE MITOCHONDRIAL IRON SULFUR CLUSTER ASSEMBLY PATHWAY

Iron-sulfur clusters are an important class of prosthetic group involved in electron transfer, enzyme catalysis, and regulation of gene expression. Their biosynthesis requires complex machinery located within the mitochondrion since free iron and sulfide are extremely toxic to the cell. Defects in this pathway results in several diseases such as Friedreich's Ataxia (FRDA), Sideroblastic Anemia and ISCU Myopathy. Therefore molecular details of the biogenesis pathway will provide deep insight in the pathway and treatment options for these diseases. FRDA is caused by deficiency of a single protein called as `Frataxin'. …

Nmr Assignments Of A Stable Processing Intermediate Of Human Frataxin, Kalyan C. Kondapalli, Krisztina Z. Bencze, Eric Dizin, James A. Cowan, Timothy L. Stemmler

Biochemistry and Molecular Biology Faculty Publications

Frataxin, a nuclear encoded protein targeted to the mitochondrial matrix, has recently been implicated as an iron chaperone that delivers ferrous iron to the iron-sulfur assembly enzyme IscU. During transport across the mitochondrial membrane, the N-terminal mitochondrial targeting sequence of frataxin is cleaved in a two-step process to produce the mature protein found in the matrix, however N-terminal extended forms of the protein have also been observed in vivo. The recent structural characterization studies of the human frataxin ortholog were performed on a truncated variant of the protein. Here we report the NMR spectral assignment of an extended form of …

Isothermal Titration Calorimetry Studies Of Protein-Mediated Interactions And Preliminary Structural Studies Of Tandem Pdz1-2 Domain Of Psd-95 Protein, Ana Jankovic

Wayne State University Dissertations

Protein-mediated interactions that involve multiple ligands in their binding mechanisms are critical for many cellular functions. The primary focus of this dissertation research was to investigate such interactions for two proteins, the PDZ domain and frataxin, involving peptide and metal binding ligands, respectively. The three component projects of this work comprised (1) thermodynamic analysis of PDZ domain binding using calorimetry; (2) X-ray crystallographic structural studies of a PDZ dual domain; and (3) thermodynamic analysis of frataxin binding to iron. The specific goal of the research conducted with the PDZ domains was to understand the mechanism of action of multiple/tandem protein …