AU4S: a novel synthetic peptide to measure the activity of ATG4 in living cells.

ABSTRACT: ATG4 plays a key role in autophagy induction, but the methods for monitoring ATG4 activity in living cells are limited. Here we designed a novel fluorescent peptide named AU4S for noninvasive detection of ATG4 activity in living cells, which consists of the cell-penetrating peptide (CPP), ATG4-recognized sequence "GTFG," and the fluorophore FITC. Additionally, an ATG4-resistant peptide AG4R was used as a control. CPP can help AU4S or AG4R to penetrate cell membrane efficiently. AU4S but not AG4R can be recognized and cleaved by ATG4, leading to the change of fluorescence intensity. Therefore, the difference between AU4S- and AG4R-measured fluorescence values in the same sample, defined as "F-D value," can reflect ATG4 activity. By detecting the F-D values, we found that ATG4 activity paral

SUBMITTER: Ni Z 

PROVIDER: S-EPMC4502827 | biostudies-literature | 2015

REPOSITORIES: biostudies-literature