Extended Data Fig. 5: Degradation of endogenous targets.
From: Methylarginine targeting chimeras for lysosomal degradation of intracellular proteins
a, Modeling of MrTACJQ1. MrTACJQ1 bound to BRD4 bromodomain 1 (BD1; PDB: 3MXF) and HaloTag (PDB: 6U32). Pink arrow shows direction of PRMT1 fusion (left). BRD4 BD1 binding to MrTACJQ1 compared against JQ1 ligand (gold; middle). HaloTag binding to MrTACJQ1 compared against tetramethylrhodamine-HaloTag (TMR-HT) ligand (gold; right). b, Quantification of immunoblot in Fig 5b by one-way ANOVA with Bonferroni’s multiple comparisons, *P0.1 < 0.0169, **P1 < 0.0076, **P10 < 0.0069. c, Immunoblot analysis of PRMT1-Halo levels through a 4-h MrTACJQ1 treatment (n = 3). d, Quantification of immunoblot in Fig 5f by one-way ANOVA with Bonferroni’s multiple comparisons, *P < 0.0221 (nMrTAC = 4, nControl = 3). e, Immunoblot analysis of PRMT1 levels through a 4-h MrTACSAHA treatment in HEK293s stably expressing PRMT1-Halo (n = 3; left). Right quantifies levels of total PRMT1 (Halo-tagged and monomeric, uncropped blot in source data) relative to 0 µM; ns by one-way ANOVA with Bonferroni’s multiple comparisons. f, Immunofluorescence of PRMT1-Halo in stably expressing HEK293 cells following a 4-h MrTACSAHA treatment with a lysosome-associated membrane protein 1 (LAMP-1) costain; scale bar is 5 µm. g, Analysis of HDAC6 levels through a 4-h MrTACSAHA treatment in HeLa cells transiently expressing PRMT1-Halo by immunoblot (n = 3; left) and immunofluorescence (n = 200 cells; middle); graph shows HDAC6 intensity over total cells marked by DAPI. ****P < 0.0001 by unpaired two-sided t-test (right). h, Immunoblot analysis of HDAC6 levels with MrTACSAHA (1 µM, 4 h) in HEK293s stably expressing PRMT1-Halo co-treated with lysosome inhibitor bafilomycin (400 nM, 2 h pre-treatment) or proteasome inhibitor MG132 (10 µM; n = 3; left). Right, total levels of HDAC6 in +MrTAC cells relative to either group’s -MrTAC condition. *P < 0.0445 by unpaired two-sided t-test. Immunoblots are representative of at least three independent experiments. Data are represented as means ± SEM.
