Kim J, Park J, Bae E, Shong M, Kim JM, Lee SB, Kim Y, Song S, Lee S, Kim S, Chung J
[
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.
Avery L, Starich TA, Phelen P, Lee RYN, Wyman RJ, Barnes TM, Bacon JP, Hekimi S, Shaw JE, Curtin KA, Baines RA, Todman M, Ford C, Davies JA, Sun Y-a, Stebbings LA
[
Trends Genet,
1998]
In vertebrates, intercellular communication via gap junctions is mediated by the connexin family of molecules, which is made up of at least 13 members. These proteins, which have four transmembrane domains and intracellular C- and N-termini, oligomerize to form hemichannels. Oligomers in the adjacent membranes of two closely apposed cells 'dock' to form intercellular channels, through which ions and small molecules move.