title: Cellular localization and tissue distribution of endogenous DFCP1 protein.
abstract: Autophagy is essential for the maintenance of cellular metabolism. Once autophagy is induced in cells, the isolation membrane forms a so-called phagophore. The endoplasmic reticulum (ER) is one of several candidates for the membrane source for phagophores. Recently, LC3-positive isolation membranes were found to emerge from a DFCP1 (double FYVE domain-containing protein)-positive, ER-associated compartment called the omegasome. Although the GFP-tagged DFCP1 protein has been examined in cultured cells, little is known about the precise cellular and tissue distribution of this endogenous protein. To determine the expression of the endogenous DFCP1 protein, we produced antibodies specific to mouse DFCP1 protein. The antibody recognized both human and mouse DFCP1 proteins, both of which have molecular masses of approximately 87 kDa. In HeLa cells under normal conditions, immunoreactivity for DFCP1 was found dotted or tubular along Tom20-positive filamentous mitochondria and was only partially co-localized in the ER or Golgi apparatus. Moreover, under starved conditions, distinct DFCP1-positive structures became more dotted and scattered in the cytoplasm, while one part of the LC3-positive autophagosomes were immunopositive for DFCP1. These results indicate that an antibody raised against DFCP1 could be a useful tool in explaining the mechanism of phagophore formation from omegasome compartments.
authors: Departments of Cellular and Molecular Neuropathology, Juntendo University Graduate School of Medicine.
authors: Tomohisa
authors: T
authors: Nanao
authors: Masato
authors: M
authors: Koike
authors: Junji
authors: J
authors: Yamaguchi
authors: Mitsuho
authors: M
authors: Sasaki
authors: Yasuo
authors: Y
authors: Uchiyama
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies / Q000737:chemistry; D002352:Carrier Proteins / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D002540:Cerebral Cortex / Q000166:cytology; D019084:Fluorescent Antibody Technique, Indirect; D006367:HeLa Cells; D006801:Humans; D008297:Male; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D009474:Neurons / Q000378:metabolism; D009928:Organ Specificity; D010446:Peptide Fragments / Q000737:chemistry / Q000276:immunology; D021381:Protein Transport
chemical_list: D000906:Antibodies; D002352:Carrier Proteins; D010446:Peptide Fragments; C426003:ZFYVE1 protein, human