Golgi-resident Small GTPase Rab33B Interacts with Atg16L and Modulates Autophagosome Formation

• Takashi Itoh

  *Department of Developmental Biology and Neurosciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8578, Japan;

• Naonobu Fujita

  Department of Cellular Regulation, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871, Japan; and

• Eiko Kanno

  *Department of Developmental Biology and Neurosciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8578, Japan;

• Akitsugu Yamamoto

  Department of Cell Biology, Nagahama Institute of Bio-Science and Technology, Nagahama, Shiga 526-0829, Japan

• Tamotsu Yoshimori

  Department of Cellular Regulation, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871, Japan; and

• Mitsunori Fukuda

  *Department of Developmental Biology and Neurosciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8578, Japan;

• Akihiko Nakano

  editor

Abstract

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.

Journal

• Molecular Biology of the Cell

  Molecular Biology of the Cell 19 (7), 2916-2925, 2008-07

  American Society for Cell Biology (ASCB)

Keywords

• Cell Biology
• Molecular Biology

Details

• CRID: 1360002217491424384
• NII Article ID: 120001820942
• DOI: 10.1091/mbc.e07-12-1231
• ISSN: 19394586
• ISSN: 10591524
• Data Source:
  • Crossref
  • CiNii Articles
  • KAKEN