Fig. 1: TyrRS protein is decreased in the hippocampal region of AD patients, and tyrosine decreases nuclear and neurite levels of TyrRS.

a Representative immunoblots and quantification for TyrRS and PheRSα/β using anti-TyrRS and PheRSα/β antibodies in the hippocampal region of AD patients (n = 7) with age and sex-matched controls (n = 7). b Tyrosine preferentially decreases nuclear and neurite levels of TyrRS. Spectral images (scale bar, 20 µm) and quantitative IF analysis of TyrRS in the nucleus, soma, and neurite of rat cortical neurons (DIV 9) using anti-TyrRS antibody after treatment with L-tyrosine (250 μM) for 4 hr (n = 3). c Reduction in tyrosine level increases the nuclear and neurite levels of TyrRS. Spectral images (scale bar, 20 µm) and quantitative IF analysis of TyrRS in the nucleus, soma, and neurite of rat cortical neurons (DIV 9) using anti-TyrRS antibody after treatment with low tyrosine medium for 2 hr as described in methods (n = 3). d Reduction in tyrosine levels increase total TyrRS protein levels. Representative immunoblots showing total TyrRS after treatment with low tyrosine medium for 2 hr in rat cortical neurons (DIV 9) using anti-TyrRS antibody (n = 3). e Tyrosine depletes TyrRS and PheRSβ, but not PheRSα. Rat cortical neurons were treated with L-tyrosine (100–300 μM) for 4 hr. The levels of PheRSβ and PheRSα were detected by WB analysis using their specific antibodies (n = 3). f TyrRS knockdown using siRNA induces neurite degeneration. Representative images (scale bar, 20 µm) for cortical neurons 72 hr following siRNA^TyrRS transfection (MAP2 – neurite marker, magenta, and DAPI – nuclear marker, blue). Neurons were immunoassayed with anti-MAP2 antibody and quantified for neurite degeneration. The data is presented as mean ± SEM for n = 3 experiments. Statistical significance was measured using a two-tailed unpaired t-test. Source data are provided as a Source Data file.