title: Atg9A protein, an autophagy-related membrane protein, is localized in the neurons of mouse brains.
abstract: Old and unneeded intracellular macromolecules are delivered through autophagy to lysosomes that degrade macromolecules into bioactive monomers such as amino acids. Autophagy is conserved in eukaryotes and is essential for the maintenance of cellular metabolism. Currently, more than 30 autophagy-related genes (Atgs) have been identified in yeast. Of these genes, the18 that are essential for autophagosome formation are also conserved in mammalian cells. Atg9 is the only transmembrane Atg protein required for autophagosome formation. Although the subcellular localization of the Atg9A protein (Atg9Ap) has been examined, little is known about its precise cell and tissue distribution. To determine this, we produced an antibody specific to mouse Atg9Ap. The antibody recognized both non-glycosylated and glycosylated Atg9Ap, which have molecular masses of approximately 94 kDa and 105 kDa, respectively. Although Atg9Ap was ubiquitously detected, it was highly expressed in neurons of the central nervous system. In Purkinje cells, Atg9Ap immunoreactivity was localized in the endoplasmic reticulum (ER), trans-Golgi network (TGN), lysosomes/late endosomes, and in axon terminals. These results suggest that Atg9Ap may be involved in autophagosome formation in the ER and axon terminals of neurons, the TGN, and lysosomes/late endosomes.
authors.affiliation: Department of Cell Biology and Neuroscience, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan.
authors.forename: Hirosumi
authors.initials: H
authors.lastname: Tamura
authors.forename: Masahiro
authors.initials: M
authors.lastname: Shibata
authors.forename: Masato
authors.initials: M
authors.lastname: Koike
authors.forename: Mitsuho
authors.initials: M
authors.lastname: Sasaki
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Uchiyama
mesh_terms: D000818:Animals; D001343:Autophagy; D000071183:Autophagy-Related Proteins; D001369:Axons / Q000378:metabolism; D001921:Brain / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D009474:Neurons / Q000378:metabolism*; D009928:Organ Specificity; D011689:Purkinje Cells / Q000378:metabolism; D033921:Vesicular Transport Proteins
chemical_list: C549015:Atg9A protein, mouse; D000071183:Autophagy-Related Proteins; D008565:Membrane Proteins; D033921:Vesicular Transport Proteins