Table S1.
LC-MS/MS results for WNK4 expressed in HEK293 cells
| Mod. | Start | End | Sequence | Score | M+ | m/z | Conserv. in n species |
| 6 | 35 | NTETGVPMSQTEADLALRPSPALTSTGPTR | 15.68 | 3 | 1040.2 | ||
| Phos (S64) | 62 | 94 | RSSVDLGLLSSWSQPASLLPEPPDPPDSAGPTR | 58.72 | 3 | 1170.6 | 19 |
| Phos (S63/S100) | 62 | 101 | RSSVDLGLLSSWSQPASLLPEPPDPPDSAGPTRSPPSSSK | 24.84 | 4 | 1072.3 | 19 (S63), 16 (S100) |
| 63 | 94 | SSVDLGLLSSWSQPASLLPEPPDPPDSAGPTR | 56.57 | 3 | 1091.9 | ||
| Phos (S99) | 63 | 101 | SSVDLGLLSSWSQPASLLPEPPDPPDSAGPTRSPPSSSK | 101.2 | 3 | 1342.0 | 14 |
| Phos (S95) | 95 | 115 | SPPSSSKEPPEGTWMGAAPVK | 92.7 | 3 | 744.7 | 13 |
| 102 | 115 | EPPEGTWMGAAPVK | 94.46 | 2 | 738.4 | ||
| ✓ | 116 | 134 | AVDSACPELTGSSGGPGSR | 4.8 | 3 | 719.9 | |
| 135 | 145 | EPPRVPDAAAR | 42.58 | 2 | 589.8 | ||
| 148 | 169 | RREQEEKEDTETQAVATSPDGR | 64.05 | 3 | 844.7 | ||
| 149 | 169 | REQEEKEDTETQAVATSPDGR | 78.91 | 3 | 792.7 | ||
| 150 | 169 | EQEEKEDTETQAVATSPDGR | 96.41 | 2 | 1110.5 | ||
| 155 | 169 | EDTETQAVATSPDGR | 118.55 | 2 | 788.9 | ||
| 173 | 179 | FDIEIGR | 58.07 | 2 | 425.2 | ||
| ✓ | 180 | 187 | GSFKTVYR | 4.15 | 2 | 607.2 | |
| 215 | 223 | FSEEVEMLK | 77.09 | 2 | 567.3 | ||
| 224 | 232 | GLQHPNIVR | 49.46 | 2 | 517.3 | ||
| ✓ | 243 | 260 | GQVCIVLVTELMTSGTLK | 4.79 | 4 | 519.3 | |
| 284 | 291 | GLHFLHSR | 54.9 | 2 | 483.8 | ||
| 292 | 298 | VPPILHR | 58.29 | 2 | 416.3 | ||
| 302 | 315 | CDNVFITGPSGSVK | 51.68 | 2 | 712.3 | ||
| 316 | 326 | IGDLGLATLKR | 84.62 | 2 | 578.9 | ||
| 316 | 325 | IGDLGLATLK | 97.46 | 2 | 500.8 | ||
| Phos (S332) | 332 | 348 | SVIGTPEFMAPEMYEEK | 74.26 | 2 | 1022.4 | 28 |
| 349 | 383 | YDEAVDVYAFGMCMLEMATSEYPYSECQNAAQIYR | 18.41 | 3 | 1386.9 | ||
| 385 | 396 | VTSGTKPNSFYK | 68.07 | 2 | 664.8 | ||
| 418 | 430 | FTIQDLLAHAFFR | 100.25 | 2 | 794.9 | ||
| 434 | 451 | GVHVELAEEDDGEKPGLK | 108.49 | 2 | 961.5 | ||
| 467 | 479 | DNQAIEFLFQLGR | 115.16 | 2 | 775.9 | ||
| ✓ | 480 | 505 | DAAEEVAQEMVALGLVCEADYQPVAR | 5.91 | 3 | 956.4 | |
| ✓ | 627 | 657 | SGPGSDFSPGDSYASDAASGLSDMGEGGQMR | 86.58 | 3 | 1030.4 | |
| 672 | 683 | LRVTSVSDQSDR | 36.3 | 2 | 691.9 | ||
| Phos (S676) | 674 | 683 | VTSVSDQSDR | 71.39 | 2 | 592.2 | 15 |
| 684 | 695 | VVECQLQTHNSK | 85.85 | 2 | 696.4 | ||
| 701 | 726 | FDLDGDSPEEIAAAMVYNEFILPSER | 47.76 | 3 | 982.1 | ||
| 727 | 732 | DGFLSR | 22.3 | 1 | 704.4 | ||
| 733 | 739 | IREIIQR | 36.38 | 2 | 464.3 | ||
| 740 | 746 | VETLLKR | 39.42 | 2 | 429.8 | ||
| Phos (S759) | 747 | 780 | DAGPPEAAEDALSPQEEPAALPALPGPPNAEPQR | 85.86 | 3 | 1161.5 | 14 |
| Phos (S783) | 781 | 787 | SISPEQR | 43.32 | 2 | 453.7 | 26 |
| 971 | 981 | NPAQPLLGDAR | 78.66 | 2 | 581.3 | ||
| 982 | 996 | LAPISEEGKPQLVGR | 96.89 | 2 | 797.4 | ||
| 997 | 1003 | FQVTSSK | 52.25 | 2 | 401.7 | ||
| Phos (S1014) | 997 | 1019 | FQVTSSKEPAEPPLQPASPTLSR | 79.88 | 2 | 1274.1 | 11 |
| Phos (S1014) | 1004 | 1019 | EPAEPPLQPASPTLSR | 58.14 | 2 | 885.4 | 11 |
| Phos (S1025) | 1020 | 1046 | SLKLPSPPLTSESSDTEDSAAGGPETR | 54.65 | 3 | 942.4 | 16 |
| Phos (S1033) | 1023 | 1046 | LPSPPLTSESSDTEDSAAGGPETR | 83.42 | 2 | 1241.0 | 16 |
| Phos (S1052) | 1047 | 1054 | EALAESDR | 37.99 | 2 | 485.7 | 14 |
| 1055 | 1071 | AAEGLGVAVDDEKDEGK | 116.81 | 2 | 851.9 | ||
| 1055 | 1067 | AAEGLGVAVDDEK | 109.36 | 2 | 637.3 | ||
| 1122 | 1136 | QKHLSEVEALQTLQK | 87.6 | 2 | 876.5 | ||
| 1124 | 1136 | HLSEVEALQTLQK | 118.72 | 2 | 748.4 | ||
| 1138 | 1145 | EIEDLYSR | 51.83 | 2 | 512.7 | ||
| 1146 | 1166 | LGKQPPPGIVAPAAMLSCRQR | 2.95 | 2 | 1116.6 | ||
| Phos (S1169) | 1167 | 1177 | RLSKGSFPTSR | 28.51 | 2 | 698.3 | 27 |
| Phos (S1172) | 1168 | 1177 | LSKGSFPTSR | 35.83 | 2 | 580.3 | 26 |
| Phos (S1176) | 1171 | 1177 | GSFPTSR | 24.25 | 2 | 416.2 | 23 |
| ✓ | 1178 | 1194 | RNSLQRSDLPGPGIMRR | 2.07 | 3 | 710.3 | |
| Phos (S1180) | 1178 | 1183 | RNSLQR | 30.84 | 2 | 427.2 | 27 |
| 1184 | 1193 | SDLPGPGIMR | 80.16 | 2 | 521.8 | ||
| Phos (S1196) | 1194 | 1208 | RNSLSGSSTGSQEQR | 112.17 | 2 | 837.4 | 24 |
| ✓ | 1194 | 1211 | RNSLSGSSTGSQEQRASK | 7.52 | 3 | 733.9 | |
| Phos (S1196) | 1195 | 1208 | NSLSGSSTGSQEQR | 82.09 | 2 | 759.3 | 24 |
| 1212 | 1221 | GVTFAGDIGR | 70.07 | 2 | 496.8 |
Observed peptides are presented. Mod, variable modification; Phos, phosphorylation; Score, MASCOT score. Peptide sequences are numbered according to position in mouse WNK4. Phosphorylated residues are underlined. Check mark means that the peptide was phosphorylated but the phosphorylated residue could not be assigned. Conservation of the identified phosphorylation sites was analyzed in 28 vertebrate species (including fish, birds, reptiles, amphibians, and mammals). The last column indicates the number of species in which the residue was found to be conserved. N-terminal RRXS sites lie within a conserved region of the protein across vertebrate classes, except fish. C-terminal phosphorylation sites located after S1169 lie within a region that is conserved among all vertebrates analyzed. S783 is conserved in most vertebrates; however, the surrounding sequence is only conserved among mammals. S332 is the T-loop phosphorylation site, which lies within the kinase domain and is conserved in all orthologs. All other sites are generally only conserved among mammals.