First Author | Itoh T | Year | 2008 |
Journal | Mol Biol Cell | Volume | 19 |
Issue | 7 | Pages | 2916-25 |
PubMed ID | 18448665 | Mgi Jnum | J:190086 |
Mgi Id | MGI:5447922 | Doi | 10.1091/mbc.E07-12-1231 |
Citation | Itoh T, et al. (2008) Golgi-resident small GTPase Rab33B interacts with Atg16L and modulates autophagosome formation. Mol Biol Cell 19(7):2916-25 |
abstractText | Macroautophagy is a mechanism of degradation of cytoplasmic components in all eukaryotic cells. In macroautophagy, cytoplasmic components are wrapped by double-membrane structures called autophagosomes, whose formation involves unique membrane dynamics, i.e., de novo formation of a double-membrane sac called the isolation membrane and its elongation. However, the precise regulatory mechanism of isolation membrane formation and elongation remains unknown. In this study, we showed that Golgi-resident small GTPase Rab33B (and Rab33A) specifically interacts with Atg16L, an essential factor in isolation membrane formation, in a guanosine triphosphate-dependent manner. Expression of a GTPase-deficient mutant Rab33B (Rab33B-Q92L) induced the lipidation of LC3, which is an essential process in autophagosome formation, even under nutrient-rich conditions, and attenuated macroautophagy, as judged by the degradation of p62/sequestosome 1. In addition, overexpression of the Rab33B binding domain of Atg16L suppressed autophagosome formation. Our findings suggest that Rab33 modulates autophagosome formation through interaction with Atg16L. |