Autophagy Induced by Calcium Phosphate Precipitates Involves Endoplasmic Reticulum Membranes in Autophagosome Biogenesis

Autor: Massaki Komatsu, Daohong Chen, Min Li, Xiao Ming Yin, Jun-Lin Guan, Xi Chen, Wentao Gao
Rok vydání: 2012
Předmět:
Calcium Phosphates
Autophagosome
Immunoblotting
ATG5
lcsh:Medicine
chemistry.chemical_element
Biology
Calcium
Endoplasmic Reticulum
Biochemistry
Signaling Pathways
Cell Line
03 medical and health sciences
chemistry.chemical_compound
0302 clinical medicine
Phagosomes
Molecular Cell Biology
Autophagy
Calcium-Mediated Signal Transduction
Humans
Phosphatidylinositol
Protein Interactions
lcsh:Science
Cellular Stress Responses
030304 developmental biology
0303 health sciences
Multidisciplinary
Cell Death
Endoplasmic reticulum
lcsh:R
Proteins
Cellular Structures
Cell biology
Subcellular Organelles
nervous system
chemistry
030220 oncology & carcinogenesis
Autophagosome membrane
Unfolded protein response
Membranes and Sorting
lcsh:Q
psychological phenomena and processes
Research Article
Signal Transduction
Zdroj: PLoS ONE, Vol 7, Iss 12, p e52347 (2012)
PLoS ONE
ISSN: 1932-6203
DOI: 10.1371/journal.pone.0052347
Popis: Calcium can play an important role in the regulation of autophagy. We previously reported that exogenously introduced calcium in the form of calcium phosphate precipitates (CPP) induces autophagy. Here we showed that CPP-induced autophagy required the classical autophagic machinery, including the autophagosome initiating molecules FIP200 and Beclin 1, as well as molecules involved in the autophagosome membrane extension, Atg4, Atg5 and Atg3. On the other hand, Atg9 seemed to place a restriction on CPP-induced autophagy. Loss of Atg9 led to enhanced LC3 punctation and enhanced p62 degradation. CPP-induced autophagy was independent of mTOR and reactive oxygen species. It also did not affect MAP kinase activation and ER stress. DFCP1 is an ER-resident molecule that binds to phosphatidylinositol 3-phosphate. CPP activated DFCP1 punctation in a class III phosphatidylinositol-3-kinase and calcium dependent manner, and caused the association of DFCP1 puncta with the autophagosomes. Consistently, ER membranes, but not Golgi or mitochondrial membranes, colocalized with CPP-induced LC3 positive autophagosomes. These data suggest that CPP-induced autophagosome formation involves the interaction with the ER membrane.
Databáze: OpenAIRE