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Cole TR, Erickson SG, Morales KA, Sung M, Holzenburg A, Igumenova TI. Cd(II)- and Pb(II)-Induced Self-Assembly of Peripheral Membrane Domains from Protein Kinase C. Biochemistry 2019; 58:509-513. [PMID: 30584764 DOI: 10.1021/acs.biochem.8b01235] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Cd2+ and Pb2+ are xenobiotic heavy metal ions that use ionic mimicry to interfere with the cellular function of biomacromolecules. Using a combination of SAXS, electron microscopy, FRET, and solution NMR spectroscopy, we demonstrate that treatment with Cd2+ and Pb2+ causes self-assembly of protein kinase C regulatory domains that peripherally associate with membranes. The self-assembly process successfully competes with ionic mimicry and is mediated by conserved protein regions that are distinct from the canonical Ca2+-binding motifs of protein kinase C. The ability of protein oligomers to interact with anionic membranes is enhanced compared to the monomeric species. Our findings suggest that metal-ion-dependent peripheral membrane domains can be utilized for generating protein-metal-ion nanoclusters and serve as biotemplates for the design of sequestration agents.
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Affiliation(s)
- Taylor R Cole
- Department of Biochemistry and Biophysics , Texas A&M University , 300 Olsen Boulevard , College Station , Texas 77843 , United States
| | - Samuel G Erickson
- Department of Biochemistry and Biophysics , Texas A&M University , 300 Olsen Boulevard , College Station , Texas 77843 , United States
| | - Krystal A Morales
- Department of Biochemistry and Biophysics , Texas A&M University , 300 Olsen Boulevard , College Station , Texas 77843 , United States
| | - MinWoo Sung
- Department of Biology , Texas A&M University , College Station , Texas 77843 , United States
| | - Andreas Holzenburg
- School of Medicine , University of Texas Rio Grande Valley , Harlingen , Texas 78550 , United States
| | - Tatyana I Igumenova
- Department of Biochemistry and Biophysics , Texas A&M University , 300 Olsen Boulevard , College Station , Texas 77843 , United States
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Xiao B, Kuang Z, Zhan Y, Chen D, Gao Y, Li M, Luo S, Hao W. A Novel Polyclonal Antiserum against Toxoplasma gondii Sodium Hydrogen Exchanger 1. THE KOREAN JOURNAL OF PARASITOLOGY 2016; 54:21-9. [PMID: 26951975 PMCID: PMC4792324 DOI: 10.3347/kjp.2016.54.1.21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Revised: 12/21/2015] [Accepted: 12/29/2015] [Indexed: 11/23/2022]
Abstract
The sodium hydrogen exchanger 1 (NHE1), which functions in maintaining the ratio of Na+ and H+ ions, is widely distributed in cell plasma membranes. It plays a prominent role in pH balancing, cell proliferation, differentiation, adhesion, and migration. However, its exact subcellular location and biological functions in Toxoplasma gondii are largely unclear. In this study, we cloned the C-terminal sequence of T. gondii NHE1 (TgNHE1) incorporating the C-terminal peptide of NHE1 (C-NHE1) into the pGEX4T-1 expression plasmid. The peptide sequence was predicted to have good antigenicity based on the information obtained from an immune epitope database. After induction of heterologous gene expression with isopropyl-b-D-thiogalactoside, the recombinant C-NHE1 protein successfully expressed in a soluble form was purified by glutathione sepharose beads as an immunogen for production of a rabbit polyclonal antiserum. The specificity of this antiserum was confirmed by western blotting and immunofluorescence. The antiserum could reduce T. gondii invasion into host cells, indicated by the decreased TgNHE1 expression in T. gondii parasites that were pre-incubated with antiserum in the process of cell entry. Furthermore, the antiserum reduced the virulence of T. gondii parasites to host cells in vitro, possibly by blocking the release of Ca2+. In this regard, this antiserum has potential to be a valuable tool for further studies of TgNHE1.
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Affiliation(s)
- Bin Xiao
- State Key Laboratory of Organ Failure, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Biotechnology, Southern Medical University, Guangzhou 510515, People's Republic of China
| | - Zhenzhan Kuang
- State Key Laboratory of Organ Failure, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Biotechnology, Southern Medical University, Guangzhou 510515, People's Republic of China
| | - Yanli Zhan
- State Key Laboratory of Organ Failure, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Biotechnology, Southern Medical University, Guangzhou 510515, People's Republic of China
| | - Daxiang Chen
- State Key Laboratory of Organ Failure, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Biotechnology, Southern Medical University, Guangzhou 510515, People's Republic of China
| | - Yang Gao
- State Key Laboratory of Organ Failure, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Biotechnology, Southern Medical University, Guangzhou 510515, People's Republic of China
| | - Ming Li
- State Key Laboratory of Organ Failure, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Biotechnology, Southern Medical University, Guangzhou 510515, People's Republic of China
| | - Shuhong Luo
- State Key Laboratory of Organ Failure, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Biotechnology, Southern Medical University, Guangzhou 510515, People's Republic of China
| | - Wenbo Hao
- State Key Laboratory of Organ Failure, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Biotechnology, Southern Medical University, Guangzhou 510515, People's Republic of China
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