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Full-Text Articles in Biochemistry
Structure And Dynamics Of Metalloproteins In Live Cells, Jeremy D. Cook, James E. Penner-Hahn, Timothy L. Stemmler
Structure And Dynamics Of Metalloproteins In Live Cells, Jeremy D. Cook, James E. Penner-Hahn, Timothy L. Stemmler
Biochemistry and Molecular Biology Faculty Publications
X-ray absorption spectroscopy (XAS) has emerged as one of the premier tools for investigating the structure and dynamic properties of metals in cells and in metal containing biomolecules. Utilizing the high flux and broad energy range of X-rays supplied by synchrotron light sources, one can selectively excite core electronic transitions in each metal. Spectroscopic signals from these electronic transitions can be used to dissect the chemical architecture of metals in cells, in cellular components and in biomolecules at varying degrees of structural resolution. With the development of ever-brighter X-ray sources, X-ray methods have grown into applications that can be utilized …
Evolution Of Metal(Loid) Binding Sites In Transcriptional Regulators, Efrén Ordóñez, Saravanamuthu Thiyagarajan, Jeremy D. Cook, Timothy L. Stemmler, José A. Gil., Luís M. Mateos, Barry P. Rosen
Evolution Of Metal(Loid) Binding Sites In Transcriptional Regulators, Efrén Ordóñez, Saravanamuthu Thiyagarajan, Jeremy D. Cook, Timothy L. Stemmler, José A. Gil., Luís M. Mateos, Barry P. Rosen
Biochemistry and Molecular Biology Faculty Publications
Expression of the genes for resistance to heavy metals and metalloids is transcriptionally regulated by the toxic ions themselves. Members of the ArsR/SmtB family of small metalloregulatory proteins respond to transition metals, heavy metals and metalloids, including As(III), Sb(III), Cd(II), Pb(II), Zn(II), Co(II) and Ni(II). These homodimeric repressors bind to DNA in absence of inducing metal(loid) ion and dissociate from the DNA when inducer is bound. The regulatory sites are often three- or four-coordinate metal binding sites composed of cysteine thiolates. Surprisingly, in two different As(III)-responsive regulators, the metalloid binding sites were in different locations in the repressor, and the …
A Cytosolic Iron Chaperone That Delivers Iron To Ferritin, Haifeng Shi, Krisztina Z. Bencze, Timothy L. Stemmler, Caroline C. Philpott
A Cytosolic Iron Chaperone That Delivers Iron To Ferritin, Haifeng Shi, Krisztina Z. Bencze, Timothy L. Stemmler, Caroline C. Philpott
Biochemistry and Molecular Biology Faculty Publications
Ferritins are the main iron storage proteins found in animals, plants and bacteria. The capacity to store iron in ferritin is essential for life in mammals, but the mechanism by which cytosolic iron is delivered to ferritin is unknown. Human ferritins expressed in yeast contain little iron. The human Poly r(C)-Binding Protein 1 (PCBP1) increased the amount of iron loaded into ferritin when expressed in yeast. PCBP1 bound to ferritin in vivo, and bound iron and facilitated iron loading into ferritin in vitro. Depletion of PCBP1 in human cells inhibited ferritin iron loading and increased cytosolic iron pools. Thus, PCBP1 …
Novel Role Of Antioxidant-1 (Atox1) As A Copper-Dependent Transcription Factor Involved In Cell Proliferation, S. Itoh, H. W. Kim, O. Nakagawa, K. Ozumi, Susan M. Lessner, H. Aoki, K. Akram, R. D. Mckinney, M. Ushio-Fukai, T. Fukai
Novel Role Of Antioxidant-1 (Atox1) As A Copper-Dependent Transcription Factor Involved In Cell Proliferation, S. Itoh, H. W. Kim, O. Nakagawa, K. Ozumi, Susan M. Lessner, H. Aoki, K. Akram, R. D. Mckinney, M. Ushio-Fukai, T. Fukai
Faculty Publications
Copper plays a fundamental role in regulating cell growth. Many types of human cancer tissues have higher copper levels than normal tissues. Copper can also induce gene expression. However, transcription factors that mediate copper-induced cell proliferation have not been identified in mammals. Here we show that antioxidant-1 (Atox1), previously appreciated as a copper chaperone, represents a novel copper-dependent transcription factor that mediates copper-induced cell proliferation. Stimulation of mouse embryonic fibroblasts (MEFs) with copper markedly increased cell proliferation, cyclin D1 expression, and entry into S phase, which were completely abolished in Atox1-/- MEFs. Promoter analysis and EMSA revealed that copper …