The major goal of this project is to understand the molecular and cellular mechanisms that regulate the transport and distribution of copper in human cells. Copper is essential for normal growth and development of human organisms. Copper misbalance results in severe multi-system disorders exemplified by Menkes disease and Wilson's disease. The genes affected in Menkes disease and Wilson's disease code for the copper-transporting ATPases ATP7A and ATP7B, respectively. The copper-transporting ATPases play a central role in human copper homeostasis by delivering copper to the copper-dependent enzymes as well as exporting excess copper from cells. The activity of copper- ATPases is tightly regulated at the molecular and cellular level. The molecular mechanism of this regulation is poorly understood and will be elucidated in the proposed series of experiemnts, which have four specific aims.
Aim 1 will compare the regulation of ATP7A and ATP7B by the copper chaperone Atox1.
Aim 2 will determine the role of oxidation/reduction for the copper-ATPase activity.
Aim 3 is designed to understand the role of a kinase-mediated phosphorylation in modulating the Cu- ATPases activity and intracellular localization.
Aim 4 will characterize a series of Wilson's disease causing mutations to dissect their molecular and cellular consequences. The results will clarify the relative contribution of each copper-ATPase to cellular copper balance as well as the biochemical basis for incomplete compensation of one copper-ATPase by the other in disease. New tools for the analysis of copper transporters in cells will be developed. The results of this research will contribute to the development of better diagnostics and treatments for human disorders of copper metabolism.

Public Health Relevance

The project focuses on understanding the function and regulation of human copper transporters ATP7A and ATP7B, associated with Menkes disease and Wilson's disease, respectively. The studies will identify factors that modulate the activity of the copper transporters in cells and characterize the consequences of known disease- causing mutations. The results will contribute to improved diagnostic and treatment of human disorders of copper metabolism.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
5R01DK071865-08
Application #
8287092
Study Section
Special Emphasis Panel (ZRG1-BCMB-B (02))
Program Officer
Serrano, Jose
Project Start
2005-08-01
Project End
2015-06-30
Budget Start
2012-07-01
Budget End
2013-06-30
Support Year
8
Fiscal Year
2012
Total Cost
$330,250
Indirect Cost
$128,878
Name
Johns Hopkins University
Department
Physiology
Type
Schools of Medicine
DUNS #
001910777
City
Baltimore
State
MD
Country
United States
Zip Code
21218
Pierson, Hannah; Muchenditsi, Abigael; Kim, Byung-Eun et al. (2018) The Function of ATPase Copper Transporter ATP7B in Intestine. Gastroenterology 154:168-180.e5
Yu, Corey H; Yang, Nan; Bothe, Jameson et al. (2017) The metal chaperone Atox1 regulates the activity of the human copper transporter ATP7B by modulating domain dynamics. J Biol Chem 292:18169-18177
Jayakanthan, Samuel; Braiterman, Lelita T; Hasan, Nesrin M et al. (2017) Human copper transporter ATP7B (Wilson disease protein) forms stable dimers in vitro and in cells. J Biol Chem 292:18760-18774
Lutsenko, Svetlana (2016) Copper trafficking to the secretory pathway. Metallomics 8:840-52
Hatori, Yuta; Yan, Ye; Schmidt, Katharina et al. (2016) Neuronal differentiation is associated with a redox-regulated increase of copper flow to the secretory pathway. Nat Commun 7:10640
Lutsenko, Svetlana (2014) Modifying factors and phenotypic diversity in Wilson's disease. Ann N Y Acad Sci 1315:56-63
Polishchuk, Roman; Lutsenko, Svetlana (2013) Golgi in copper homeostasis: a view from the membrane trafficking field. Histochem Cell Biol 140:285-95
Hatori, Yuta; Lutsenko, Svetlana (2013) An expanding range of functions for the copper chaperone/antioxidant protein Atox1. Antioxid Redox Signal 19:945-57
Hasan, Nesrin M; Gupta, Arnab; Polishchuk, Elena et al. (2012) Molecular events initiating exit of a copper-transporting ATPase ATP7B from the trans-Golgi network. J Biol Chem 287:36041-50
Schushan, Maya; Bhattacharjee, Ashima; Ben-Tal, Nir et al. (2012) A structural model of the copper ATPase ATP7B to facilitate analysis of Wilson disease-causing mutations and studies of the transport mechanism. Metallomics 4:669-78

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