Extended Data Fig. 6: ECS1 and ECS2 endopeptidases interact with LURE1.2 and cleave it as a substrate.
From: Fertilized egg cells secrete endopeptidases to avoid polytubey
a, Protein level of LURE1.2 significantly decreased after co-expression with ECS1 and ECS2 in mammalian cells, respectively. b, Relative protein levels of LURE1.2 in leaves co-expressed with ECS1, ECS2 or the empty vector (CK) as control, respectively. Data are presented as mean ± s.d. from four independent experiments. (n = 4). Statistical test was performed using one-way ANOVA between groups, with the Tukey–Kramer test for multiple comparisons (P = 2.25 × 10−5; F = 44.03). c, Fluorogenic peptides were synthesized according to the LURE1.2 protein sequence (d). e, Proteolytic activity of recombinant ECS1 and ECS2 using LURE1.2-derived peptide 3 as substrate at different concentrations to determine Km values. Data represent mean ± s.d. of three independent experiments. f, Effect of temperature on proteolytic activities of recombinant ECS1 and ECS2 using peptide 3 as a substrate. Data represent mean ± s.d. of three independent experiments. g, Alignment of LURE and XIUQIU protein sequences. Amino acid sequence of peptide 3 (outlined by red colour) is conserved in all LURE1, but not in XIUQIU protein sequences. Full length sequences including N-terminal signal motifs are shown.
