Essential role for GABARAP autophagy proteins in interferon-inducible GTPase-mediated host defense

Nat Immunol. 2017 Jun 12. doi: 10.1038/ni.3767. [Epub ahead of print]

Sasai M1,2, Sakaguchi N1,2, Ma JS1, Nakamura S3,4, Kawabata T3,4, Bando H1, Lee Y2, Saitoh T5,6,7, Akira S5,6, Iwasaki A8, Standley DM9,10, Yoshimori T3,4, Yamamoto M1,2.

Author information

Abstract

Mammalian autophagy-related 8 (Atg8) homologs consist of LC3 proteins and GABARAPs, all of which are known to be involved in canonical autophagy. In contrast, the roles of Atg8 homologs in noncanonical autophagic processes are not fully understood. Here we show a unique role of GABARAPs, in particular gamma-aminobutyric acid (GABA)-A-receptor-associated protein-like 2 (Gabarapl2; also known as Gate-16), in interferon-γ (IFN-γ)-mediated antimicrobial responses. Cells that lacked GABARAPs but not LC3 proteins and mice that lacked Gate-16 alone were defective in the IFN-γ-induced clearance of vacuolar pathogens such as Toxoplasma. Gate-16 but not LC3b specifically associated with the small GTPase ADP-ribosylation factor 1 (Arf1) to mediate uniform distribution of interferon-inducible GTPases. The lack of GABARAPs reduced Arf1 activation, which led to formation of interferon-inducible GTPase-containing aggregates and hampered recruitment of interferon-inducible GTPases to vacuolar pathogens. Thus, GABARAPs are uniquely required for antimicrobial host defense through cytosolic distribution of interferon-inducible GTPases.

PMID:

 

28604719

 

DOI:

 

10.1038/ni.3767