N-terminal arginylation generates a bimodal degron that modulates autophagic proteolysis

Cited 34 time in scopus
Metadata Downloads
N-terminal arginylation generates a bimodal degron that modulates autophagic proteolysis
Y D Yoo; S R Mun; C H Ji; K W Sung; K Y Kang; A J Heo; S H Lee; J Y An; Joonsung Hwang; X Q Xie; A Ciechanover; Bo Yeon Kim; Y T Kwon
Bibliographic Citation
Proceedings of National Academy of Sciences of United States of America, vol. 115, no. 12, pp. e2716-e2724
Publication Year
The conjugation of amino acids to the protein N termini is universally observed in eukaryotes and prokaryotes, yet its functions remain poorly understood. In eukaryotes, the amino acid L-arginine (L-Arg) is conjugated to N-terminal Asp (Nt-Asp), Glu, Gln, Asn, and Cys, directly or associated with posttranslational modifications. Following Ntarginylation, the Nt-Arg is recognized by UBR boxes of N-recognins such as UBR1, UBR2, UBR4/p600, and UBR5/EDD, leading to substrate ubiquitination and proteasomal degradation via the N-end rule pathway. It has been a mystery, however, why studies for the past five decades identified only a handful of Nt-arginylated substrates in mammals, although five of 20 principal amino acids are eligible for arginylation. Here, we show that the Nt-Arg functions as a bimodal degron that directs substrates to either the ubiquitin (Ub)- proteasome system (UPS) or macroautophagy depending on physiological states. In normal conditions, the arginylated forms of proteolytic cleavage products, D101-CDC6 and D1156-BRCA1, are targeted to UBR box-containing N-recognins and degraded by the proteasome. However, when proteostasis by the UPS is perturbed, their Nt-Arg redirects these otherwise cellularwastes tomacroautophagy through its binding to the ZZ domain of the autophagic adaptor p62/STQSM/ Sequestosome-1. Upon binding to the Nt-Arg, p62 acts as an autophagic N-recognin that undergoes self-polymerization, facilitating cargo collection and lysosomal degradation of p62-cargo complexes. A chemical mimic of Nt-Arg redirects Ub-conjugated substrates from the UPS to macroautophagy and promotes their lysosomal degradation. Our results suggest that the Nt-Arg proteome of arginylated proteins contributes to reprogramming global proteolytic flux under stresses
ATE1 R-transferaseN-end rule pathwaymacroautophagyp62/STQSM/Sequestosome-1ubiquitin-proteasome system
Natl Acad Sciences
Appears in Collections:
Ochang Branch Institute > Chemical Biology Research Center > 1. Journal Articles
Files in This Item:
  • There are no files associated with this item.

Items in OpenAccess@KRIBB are protected by copyright, with all rights reserved, unless otherwise indicated.