[
Microsc Res Tech,
2012]
Adenosine 5'-triphosphate (ATP) is the major energy currency and is involved in many biological processes. The ATP-monitoring system for cells in animals can be helpful to study the relationship between energy metabolism and biological processes. The fluorescent ATP biosensor ATeam (ATP indicator based on Epsilon subunit for Analytical Measurements), which has been reported to monitor ATP levels in cultured cells on the basis of fluorescence resonance energy transfer (FRET), was introduced into nematodes by microinjection and UV-irradiation method. To confirm whether ATeam functions as an ATP sensor in nematode cells, the authors measured FRET of ATeam in cells of transgenic nematode. The ATeam was expressed in target cells in nematode. In vulva cells, ATP levels in the cytosol were higher than those in mitochondria. ATeam also sensed ATP level change in cultured cells from the transgenic nematode. These experiments indicated that ATeam is available for detection of changes in ATP levels in nematode cells.
Kim Y, Kim S, Kim J, Lee S, Shong M, Chung J, Song S, Kim JM, Park J, Lee SB, Bae E
[
Nature,
2006]
Autosomal recessive juvenile parkinsonism (AR-JP) is an early-onset form of Parkinson''s disease characterized by motor disturbances and dopaminergic neurodegeneration. To address its underlying molecular pathogenesis, we generated and characterized loss-of-function mutants of Drosophila PTEN-induced putative kinase 1 (PINK1), a novel AR-JP-linked gene. Here, we show that PINK1 mutants exhibit indirect flight muscle and dopaminergic neuronal degeneration accompanied by locomotive defects. Furthermore, transmission electron microscopy analysis and a rescue experiment with Drosophila Bcl-2 demonstrated that mitochondrial dysfunction accounts for the degenerative changes in all phenotypes of PINK1 mutants. Notably, we also found that PINK1 mutants share marked phenotypic similarities with parkin mutants. Transgenic expression of Parkin markedly ameliorated all PINK1 loss-of-function phenotypes, but not vice versa, suggesting that Parkin functions downstream of PINK1. Taken together, our genetic evidence clearly establishes that Parkin and PINK1 act in a common pathway in maintaining mitochondrial integrity and function in both muscles and dopaminergic neurons.