Extended Data Fig. 6: Genetic manipulation of LRRC58 in the context of hypotaurine-taurine pathway.

(a) Correlation between hypotaurine abundance calculated from LASSO prediction and hypotaurine abundance measured in BAT. n = 163 mice. (b) LASSO regression to predict hypotaurine abundance in the liver. CDO1- cysteine dioxygenase type 1; CSAD - cysteine sulfinic acid decarboxylase; FMO1- flavin containing monooxygenase 1. LRRC58 was not included in liver analysis due to its low abundance leading to 59 missing values out of 163 samples in total. Hypotaurine measurement was missing in the liver of one mouse. n = 162 mice. (c) Correlation between hypotaurine abundance calculated from LASSO prediction and hypotaurine abundance measured in liver. n = 162 mice. (d) Protein abundance of LRRC58 in scramble (scr) compared to LRRC58 siRNA A (LRRC58^siA) and siRNA B (LRRC58^siB)-treated primary brown adipocytes. n = 4 cell replicates for scr and LRRC58^siA; n = 3 cell replicates for LRRC58^siB. Data replotted from Fig. 3a. (e) Left: metabolite abundance profiling comparing scramble (scr) to LRRC58 siRNA A (LRRC58^siA)-treated primary brown adipocytes. n = 4 cell replicates. Right: metabolite abundance profiling comparing scramble (scr) to LRRC58 siRNA B (LRRC58^siB)-treated primary brown adipocytes. n = 4 cell replicates. (f) Transcript abundance of Lrrc58 in scramble (scr) compared to LRRC58^siA and LRRC58^siB-treated primary hepatocytes. n = 3 cell replicates. (g) Left: metabolite abundance profiling comparing scramble (scr) to LRRC58 siRNA A (LRRC58^siA)-treated primary hepatocytes. n = 4 cell replicates. Left: metabolite abundance profiling comparing scramble (scr) to LRRC58 siRNA B (LRRC58^siB)-treated primary hepatocytes. n = 4 cell replicates. (h) Protein abundance of LRRC58 in wild type (WT) compared LRRC58 overexpression (LRRC58^OE) in Hep G2. n = 4 cell replicates. Data replotted from Fig. 3e. (i) Metabolite abundance profiling comparing wildtype (WT) to LRRC58 overexpression (LRRC58^OE) Hep G2 cells. n = 4 cell replicates. (j) Transcript abundance of Lrrc58 in scramble (scr) compared to LRRC58 siRNA A (LRRC58^siA)-treated primary hepatocytes for the tracing experiments. n = 3 cell replicates. (k) Schematic of tracing cysteine metabolism to taurine in scramble (scr) and LRRC58^KD primary hepatocytes. Cells were treated for 30 min with 200 µM ¹³C₆¹⁵N₂-labeled L-cystine. ¹³C₃¹⁵N₁-L-cysteine, ¹³C₂¹⁵N₁-hypotaurine, and ¹³C₂¹⁵N₁-taurine are the expected major forms of isotope-labeled downstream metabolites in the hypotaurine-taurine pathway. (l) Transcript abundance of Lrrc58 and CDO1 in scramble (scr) compared to LRRC58^siA, CDO1^siA, and LRRC58^siA + CDO1^siA -treated primary hepatocytes. n = 4 cell replicates. (m) Hypotaurine, taurine and L-cysteine abundance in scramble (scr) compared to LRRC58^siA, CDO1^siA, and LRRC58^siA + CDO1^siA -treated primary hepatocytes. n = 6 cell replicates. (n, o) AP-MS of CDO1 and CUL5 from BioPlex 3.0³⁶. CompPASS plus score ranges from 0-1, and a score of 1 represents the highest confidence for identification of a physical interactor. Normalized weighted D (NWD) score takes account of the selectivity of the interaction. A higher NWD score indicates higher selectivity of the interaction. LRRC58 was identified in only 5 out of all 10,128 experiments in BioPlex 3.0. n = 2 technical replicates. (p) AP-MS of LRRC58 in LRRC58 overexpression (LRRC58^OE) Hep G2 cells (see Methods). Protein abundance presented by summed MS1 peak area. n = 4 cell replicates for LRRC58^OE. n = 1 cell replicate for background control. (q) Interactions between LRRC58, CDO1, CUL5, ELOB, and ELOC based on literature evidence and experimental data. (two-sided Pearson correlation test in a with no multiple comparison adjustment; two-tailed Student’s t-test for pairwise comparisons in d-j, l, and m with no multiple comparison adjustment. P < 0.05 considered significant). Data presented as mean ± s.e.m., error band in a and c represent 95% confidence interval.