| First Author | Masin M | Year | 2012 |
| Journal | Br J Pharmacol | Volume | 165 |
| Issue | 4 | Pages | 978-93 |
| PubMed ID | 21838754 | Mgi Jnum | J:194518 |
| Mgi Id | MGI:5474121 | Doi | 10.1111/j.1476-5381.2011.01624.x |
| Citation | Masin M, et al. (2012) Expression, assembly and function of novel C-terminal truncated variants of the mouse P2X7 receptor: re-evaluation of P2X7 knockouts. Br J Pharmacol 165(4):978-93 |
| abstractText | BACKGROUND AND PURPOSE: Splice variants of P2X7 receptor transcripts contribute to the diversity of receptor-mediated responses. Here, we investigated expression and function of C-terminal truncated (DeltaC) variants of the mP2X7 receptor, which are predicted to escape inactivation in one strain of P2X7(-/-) mice (Pfizer KO). EXPERIMENTAL APPROACH: Expression in wild-type (WT) and Pfizer KO tissue was investigated by reverse transcription (RT)-PCR and Western blot analysis. DeltaC variants were also cloned and expressed in HEK293 cells to investigate their assembly, trafficking and function. KEY RESULTS: RT-PCR indicates expression of a DeltaC splice variant in brain, salivary gland (SG) and spleen from WT and Pfizer KO mice. An additional DeltaC hybrid transcript, containing sequences of P2X7 upstream of exon 12, part of exon 13 followed in-frame by the sequence of the vector used to disrupt the P2X7 gene, was also identified in the KO mice. By blue native (BN) PAGE analysis and the use of cross linking reagents followed by SDS-PAGE, P2X7 trimers, dimers and monomers were detected in the spleen and SG of Pfizer KO mice. The molecular mass was reduced compared with P2X7 in WT mice tissue, consistent with a DeltaC variant. When expressed in HEK293 cells the DeltaC variants were inefficiently trafficked to the cell surface and agonist-evoked whole cell currents were small. Co-expressed with P2X7A, the DeltaC splice variant acted in a dominant negative fashion to inhibit function. CONCLUSIONS AND IMPLICATIONS: Pfizer KO mice are not null for P2X7 receptor expression but express DeltaC variants with reduced function. |
