Functional screening of mutant P2X7 subunits Single and double mutations in rat P2X7 subunit were designed to target residues conserved in the mammalian P2X family. The mutant receptors were assayed for their response to 50 μM BzATP. The dominant-negative (Dn) effect of the mutant subunits was determined at a 2:1 ratio with the wild-type subunit.
| Motif | Domain | Mutation | Response to BzATP | Dn Effect |
|---|---|---|---|---|
| D V F Q Y E T N K | Intracellular | Y13A | + | - |
| F Q Y E T N K V T | Intracellular | T15A | + | - |
| I/T V F S Y I/V S F A | Transmembrane | Y40A | + | - |
| V/I S/F A W C P T/A E E | Extracellular | WC167-168AA | - | + |
| Y W D C N L D S W | Extracellular | CN260-261AA | - | - |
| I K A F G I/V R F D | Extracellular | FG313-314AA | + | - |
| F G I/V R F D I L V | Extracellular | RF316-317AA | - | - |
| I/V R F D I L V F G | Extracellular | DI318-319AA | - | - |
| G T G B G K F D I T | Extracellular | GK326-327AA | + | - |
| Q L V V Y I G S T | Transmembrane | Y336A | + | - |
| V Y I G S T L S Y | Transmembrane | S339R | + | - |
| T VC I D L L/I I N | Transmembrane | D352A | + | - |