Interactions between Metal-binding Domains Modulate Intracellular Targeting of Cu(I)-ATPase ATP7B, as Revealed by Nanobody Binding.

TitleInteractions between Metal-binding Domains Modulate Intracellular Targeting of Cu(I)-ATPase ATP7B, as Revealed by Nanobody Binding.
Publication TypeJournal Article
Year of Publication2014
AuthorsHuang, Y., S. Nokhrin, G. Hassanzadeh-Ghassabeh, C. H. Yu, H. Yang, A. N. Barry, M. Tonelli, J. L. Markley, S. Muyldermans, O. Y. Dmitriev, and S. Lutsenko
JournalJ Biol Chem
Volume289
Issue47
Pagination32682-93
Date Published2014 Nov 21
ISSN1083-351X
Abstract

The biologically and clinically important membrane transporters are challenging proteins to study because of their low level of expression, multidomain structure, and complex molecular dynamics that underlies their activity. ATP7B is a copper transporter that traffics between the intracellular compartments in response to copper elevation. The N-terminal domain of ATP7B (N-ATP7B) is involved in binding copper, but the role of this domain in trafficking is controversial. To clarify the role of N-ATP7B, we generated nanobodies that interact with ATP7B in vitro and in cells. In solution NMR studies, nanobodies revealed the spatial organization of N-ATP7B by detecting transient functionally relevant interactions between metal-binding domains 1-3. Modulation of these interactions by nanobodies in cells enhanced relocalization of the endogenous ATP7B toward the plasma membrane linking molecular and cellular dynamics of the transporter. Stimulation of ATP7B trafficking by nanobodies in the absence of elevated copper provides direct evidence for the important role of N-ATP7B structural dynamics in regulation of ATP7B localization in a cell.

DOI10.1074/jbc.M114.580845
Alternate JournalJ. Biol. Chem.
PubMed ID25253690
PubMed Central IDPMC4239620
Grant ListP41 GM103399 / GM / NIGMS NIH HHS / United States
subject_category: 
Research group: