期刊
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
卷 109, 期 43, 页码 17472-17477出版社
NATL ACAD SCIENCES
DOI: 10.1073/pnas.1203106109
关键词
phosphoinositide; spongiform
资金
- National Institute of Diabetes and Digestive and Kidney Disease [DK020572]
- University of Michigan Echocardiography and Transgenic Animal Model Cores
- National Institutes of Health Research [R01 NS064015, R01 GM24872, R01 DK061618]
- Veterans Administration Merit Review Grant
- Fritz Thyssen Foundation
Mutations that cause defects in levels of the signaling lipid phosphatidylinositol 3,5-bisphosphate [PI(3,5)P-2] lead to profound neurodegeneration in mice. Moreover, mutations in human FIG4 predicted to lower PI(3,5)P-2 levels underlie Charcot-Marie-Tooth type 4J neuropathy and are present in selected cases of amyotrophic lateral sclerosis. In yeast and mammals, PI(3,5)P-2 is generated by a protein complex that includes the lipid kinase Fab1/Pikfyve, the scaffolding protein Vac14, and the lipid phosphatase Fig4. Fibroblasts cultured from Vac14(-/-) and Fig4(-/-) mouse mutants have a 50% reduction in the levels of PI(3,5)P-2, suggesting that there may be PIKfyve-independent pathways that generate this lipid. Here, we characterize a Pikfyve gene-trap mouse (Pikfyve(beta-geo/beta-geo)), a hypomorph with similar to 10% of the normal level of Pikfyve protein. shRNA silencing of the residual Pikfyve transcript in fibroblasts demonstrated that Pikfyve is required to generate all of the PI(3,5)P-2 pool. Surprisingly, Pikfyve also is responsible for nearly all of the phosphatidylinositol-5-phosphate (PI5P) pool. We show that PI5P is generated directly from PI(3,5)P-2, likely via 3'-phosphatase activity. Analysis of tissues from the Pikfyve(beta-geo/beta-geo) mouse mutants reveals that Pikfyve is critical in neural tissues, heart, lung, kidney, thymus, and spleen. Thus, PI(3,5)P-2 and PI5P have major roles in multiple organs. Understanding the regulation of these lipids may provide insights into therapies for multiple diseases.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据