Extended Data Fig. 4: The role of fatty acyl moieties in phospholipid partitioning.
From: Biomolecular condensates create phospholipid-enriched microenvironments
a, Individual phospholipid enrichment in condensates. To examine whether phospholipid head groups and fatty acyl moieties impact enrichment in condensates, we used a heat map. Each glycerophosphoryl head group, lysophospholipid and phospholipid’s median log2-fold enrichment (blue indicates condensate de-enrichment and red indicates enrichment) is plotted for nucleocapsid (left), MED1 (middle) and HNRNPA1 (right) condensates. Glycerophosphoryl head groups are sorted alphabetically, while lysophospholipids and phospholipids are sorted by the sum of carbons in their fatty acyl moieties after being grouped by head-group as demarked on the y-axis. We observe that longer phosphatidylethanolamines are less enriched in condensates for all three proteins, with similar phenomena observed with other head groups for specific proteins. This suggests that fatty acyl moiety length may reduce enrichment at least with some head groups and in some condensates (n = 3 for 150 nM RNA sample, n = 2 for other samples). b, Phospholipid fatty acyl moiety length is inversely correlated with partitioning. To determine if fatty acyl moiety chain length also contributes to partitioning, the total number of carbons in the fatty acyl moieties of lysophospholipids and phospholipids (x-axis, n = 65) was plotted against the median log2-enrichment of that lipid (y-axis) in nucleocapsid (left), MED1 (center) or HNRNPA1 (right) condensates relative to input sample using our metabolomics data. The number of unsaturated bonds is indicated (right) for each lipid with red indicating no unsaturated bonds, blue indicating more than 5 unsaturated bonds, with a gradient representing intermediate numbers of unsaturated bonds. There is no apparent correlation between the level of saturation at a given fatty acyl moiety length and the level of enrichment. On the other hand, there is a noticeable decrease in enrichment of phospholipids with longer fatty acyl moieties (>36 carbons) for all three proteins (Spearman’s rho < −0.41, p < 0.005, two-sided Spearman’s test). N = 3 replicates per protein.
