Fig. 1: ATC central activity in de novo pyrimidine synthesis and plant growth. | Nature Communications

Fig. 1: ATC central activity in de novo pyrimidine synthesis and plant growth.

From: Mechanisms of feedback inhibition and sequential firing of active sites in plant aspartate transcarbamoylase

Fig. 1

a Scheme of de novo pyrimidine biosynthesis pathway (highlighted in cyan with enzymatic activities in yellow background) and arginine synthesis (in orange) in plants. ATC, aspartate transcarbamoylase; DHO, dihydroorotase; DHODH, dihydroorotate dehydrogenase; UMPS, UMP synthetase; CPS, carbamoyl phosphate synthetase; OTC, ornithine transcarbamoylase. Allosteric inhibition by UMP and activation by ornithine are indicated by red and blue lines, respectively. b Arabidopsis Col-0 and ATC downregulated (atc-1 and -2) or overexpressing lines (ATC-Ox1 and 2) grown for 4 weeks in a 14 h light and 10 h dark regime. c ATC transcript levels in knockdown and overexpressing lines relative to Col-0 (n = 9). ATC transcript levels relative to actin: 9.5 × 10−3 (Col-0), 1.5 × 10−3 (atc-1), 0.93 × 10−4 (atc-2), 0.13 (ATC-Ox1), and 0.15 (and ATC-Ox2). p-values are 5.722 × 10−14 for atc-1, 5.93 × 10−15 for atc-2, 1.056 × 10−10 for ATC-Ox1, and 1.016 × 10−10 for ATC-Ox2. d Immunoblot with anti-ATC antibody on whole leaf extracts; Coomassie Brilliant Blue (CBB) stained SDS-PAGE was used as loading control. The ATC protein levels relative to Col-0 quantified from n-different experiments are: atc-1, 0.34 ± 0.17 (n = 5); atc-2, 0.05 ± 0.024 (n = 5); ATC-Ox1, 2.9 ± 0.44 (n = 4); and ATC-Ox2, 2.5 ±  0.87 (n = 4). e Fresh weight quantification (n = 10). f Electron transport rate (ETR) determined by PAM in standard light curve setting (n = 12 for Col-0, n = 8 for atc-1, n = 11 for atc-2, n = 12 for ATC-Ox1, n = 11 for ATC-Ox2). p-values are 2.879 × 10−18 for atc-1, 4.563 × 10−20 for atc-2, 3.692 × 10−5 for ATC-Ox1, 1.142 × 10−6 for ATC-Ox2. g False color presentation of maximal photosynthesis yield monitored by PAM of lines shown in f. Error bars indicate standard error of the mean. Asterisks depict significant changes between the different lines referring to Col-0 control according to one-way ANOVA followed by Tukey’s multiple comparison test (*p < 0.05, **p < 0.01, ***p < 0.001).

Back to article page