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Beclin–phosphatidylinositol 3‐kinase complex functions at the trans ‐Golgi network
Author(s) -
Kihara Akio,
Kabeya Yukiko,
Ohsumi Yoshinori,
Yoshimori Tamotsu
Publication year - 2001
Publication title -
embo reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.584
H-Index - 184
eISSN - 1469-3178
pISSN - 1469-221X
DOI - 10.1093/embo-reports/kve061
Subject(s) - phosphatidylinositol , microbiology and biotechnology , kinase , autophagy , golgi apparatus , endosome , biology , immunoprecipitation , chemistry , intracellular , biochemistry , endoplasmic reticulum , apoptosis , gene
Autophagy is an intracellular bulk protein degradation system. Beclin is known to be involved in this process; however, its role is unclear. In this study, we showed that Beclin was co‐immunoprecipitated with phosphatidylinositol (PtdIns) 3‐kinase, which is also required for autophagy, suggesting that Beclin is a component of the PtdIns 3‐kinase complex. Quantitative analyses using a cross‐linker showed that all Beclin forms a complex with PtdIns 3‐kinase, whereas ∼50% of PtdIns 3‐kinase remains free from Beclin. Indirect immunofluorescence microscopy demonstrated that the majority of Beclin and PtdIns 3‐kinase localize to the trans ‐Golgi network (TGN). Some PtdIns 3‐kinase is also distributed in the late endosome. These results suggest that Beclin and PtdIns 3‐kinase control autophagy as a complex at the TGN.