Involvement of TOR signaling motif in the regulation of plant autophagy

Journal Article · Fri Jun 15 04:00:00 UTC 2018 · Biochemical and Biophysical Research Communications

DOI:https://doi.org/10.1016/J.BBRC.2018.05.027· OSTI ID:23125066

Son, Ora; Kim, Sunghan ^[1]; Kim, Dooil ^[2]; Hur, Yoon-Sun; Kim, Jiyoung; Cheon, Choong-Ill ^[1]

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1. Department of Biological Science, Sookmyung Women's University, Seoul, 04310, South (Korea, Republic of)
2. Department of Biological Science, Chungbuk National University, Cheongju, 28644, South (Korea, Republic of)

Highlights: • The plant TOS motif core sequence interacting with Raptor was identified in ATG13 as well as S6K1 of the Arabidopsis. • Autophagy response was observed when the plant TOS core sequence was deleted from AtATG13. • Phosphorylation of AtATG13 was reduced significantly when the plant TOS core sequence was deleted. In our previous studies, we have demonstrated that a stretch of amino-acid sequences identified from Arabidopsis ribosomal S6 kinase 1 (AtS6K1) provided a plant version of the TOS (TOR-signaling) motif, mediating the interaction with the Raptor protein in the TOR (Target of Rapamycin) kinase complex. Here we report the presence of same element in Arabidopsis Autophagy related-13 (AtATG13) protein, which is a key component of the plant autophagy response. Its composition is nearly identical to that found in the AtS6K1 in the five-amino-acid core sequence, and the presence of this five-amino-acid sequence was found to be essential for its interaction with the Raptor protein. A mutant AtATG13 protein lacking this five-amino-acid element conferred an elevated autophagy response and could not effectively phosphorylated by TOR kinase activity, demonstrating its role in mediating the TOR signaling to the components that carry it as a possible TOS motif. A ligand-binding simulation model using the MM-PBSA method indicates that both of the five-amino-acid sequence elements of AtS6K1 and AtATG13 have strong probability of making stable interface with the Raptor binding pocket, corroborating our proposition for this element as the plant TOS motif.

• OSTI ID: 23125066
• Journal Information: Biochemical and Biophysical Research Communications, Journal Name: Biochemical and Biophysical Research Communications Journal Issue: 3 Vol. 501; ISSN BBRCA9; ISSN 0006-291X
• Country of Publication: United States
• Language: English

Related Subjects

60 APPLIED LIFE SCIENCES
AMINO ACIDS
ARABIDOPSIS
PHOSPHOTRANSFERASES