Table I. Modified aquaporin peptides.
| Name | Aquaporin | Peptide sequence | PTM | PTM positiona |
|---|---|---|---|---|
| PIP11–14 Acet | PIP1;1–1;2–1;3–1;4 | acetMEGKEEDVR14 | Acet | M1 |
| PIP11 12 (15–29) 1P | PIP1;1–1;2 | 15FPERQPIGTpSAQpSDK29 | 1P | S24, S27 |
| PIP11 12 (15–29) 1P 1Dea | PIP1;1–1;2 | 15FPERdQPIGTpSAQpSDK29 | 1P, 1Dea | 1P: S24, S27; 1Dea: Q19 |
| PIP11 12 (19–29) 1P | PIP1;1–1;2 | 19QPIGTSAQpSDK29 | 1P | S27 |
| PIP21 (4–16) 1Dea | PIP2;1 | 4DVEAVPGEGFdQTR16 | 1Dea | Q14 |
| PIP22 (4–14) 1Dea | PIP2;2 | 4DVEGPEGFdQTR14 | 1Dea | Q12 |
| PIP24 (4–16) 1Dea | PIP2;4 | 4DLDVdNESGPPAAR16 | 1Dea | N8 |
| PIP24 (4–19) 1P | PIP2;4 | 4DLDVNEpSGPPAARDYK19 | 1P | S10 |
| PIP21 (17–33) 1Dea | PIP2;1 | 17DYdQDPPPAPFIDGAELK33 | 1Dea | Q19 |
| PIP22 (15–32) 1P | PIP2;2 | 15DYEDPPPpTPFFDADELTK32 | 1P | T22 |
| PIP22 (15–32) 1Met | PIP2;2 | 15DYmEDPPPTPFFDADELTK32 | 1Met | E17 |
| PIP12 (loop C) 1Dea | PIP1;2 | 157QYQALGGGAdNTIAHGYTK174 | 1Dea | N166 |
| PIP15 (loop C) 1Dea | PIP1;5 | 153GFdQPGLYQTdNGGGAdNVVAHGYTK175 | 1Dea | Q155, N162, N167 |
| PIP24 (loop C) 1Dea | PIP2;4 | 154YGGGAdNELADGYNK167 | 1Dea | N159 |
| PIP27 (loop C) 1Dea | PIP2;7 | 142TPYNTLGGGAdNTVADGYSK160 | 1Dea | N152 |
| PIP21 (272–282) 1P | PIP2;1–2;2–2;3 | 272ASGSKSLGpSFR282 | 1P | S280 |
| PIP21 (277–282) 1P | PIP2;1–2;2–2;3 | 277SLGpSFR282 | 1P | S280 |
| PIP21 (277–287) 1P | PIP2;1–2;2–2;3 | 277SLGpSFRpSAANV287 | 1P | S280, S283 |
| PIP21 (277–287) 1P 1Dea | PIP2;1–2;2–2;3 | 277SLGpSFRpSAAdNV287 | 1P and 1Dea | 1P: S280, S283; 1Dea: N286 |
| PIP21 (277–287) 2P | PIP2;1–2;2–2;3 | 277SLGpSFRpSAANV287 | 2P | S280 + S283 |
| PIP21 (277–287) 2P 1Dea | PIP2;1–2;2–2;3 | 277SLGpSFRpSAAdNV287 | 2P and 1Dea | 2P: S280 + S283; 1Dea: N286 |
| PIP24 (276–287) 1P | PIP2;4 | 277ALGpSFGpSFGpSFR288 | 1P | S280, S283, S286 |
| PIP25 (276–286) 1P | PIP2;5 | 276ALGpSFRSQPHV286 | 1P | S279 |
| PIP27 (270–280) 1P | PIP2;7 | 270ALGpSFRSNATN280 | 1P | S273 |
| PIP27 (270–280) 2P | PIP2;7 | 270ALGpSFRpSNATN280 | 2P | S273 + S276, S276 + T279 |
| PIP27 (270–280) 1P 1Dea | PIP2;7 | 270ALGpSFRSdNATN280 | 1P and 1Dea | 1P: S273; 1Dea: N277 |
| PIP27 (270–280) 2P 1Dea | PIP2;7 | 270ALGpSFRpSdNATN280 | 2P and 1Dea | 2P: S273 + S276; 1Dea: N277 |
| PIP28 (268–278) 1P | PIP2;8 | 268ALApSFRSNPTN278 | 1P | S271 |
This table lists all aquaporin peptides harboring PTMs. The first column indicates the name of the peptide, as referred to in Fig. 4. The second and third columns contain the name of the aquaporin and the peptide sequence, respectively. The last two columns indicate the type and number of PTMs and the position of the modified residue(s). The fragmentations of peptides are detailed in supplemental Fig. S3. Acet, acetylation; Dea, deamidation; Met, methylation; P, phosphorylation; PIP1;1–1;2–1;3–1;4, PIP1;1 and/or PIP1;2 and/or PIP1;3 and/or PIP1;4; PIP1;1–1;2, PIP1;1 and/or PIP1;2; PIP2;1–2;2–2;3, PIP2;1 and/or PIP2;2 and/or PIP2;3.
a A comma indicates the coexistence of different phosphorylation or deamidation sites within a peptide (supplemental Fig. S3).