[Purpose] GABAB receptors are responsible for inhibitory transmission by conjugating with Gi proteins. In addition, this receptor functions by forming a dimer of R1 and R2 subunits (R2). Phosphorylation of serine residue at position 892 (S892) of R2 suppresses receptor internalization and desensitization. We have investigated the possibility that protein phosphatase 5 (PP5) dephosphorylates S892. In this study, we investigated the effect of overexpression of PP5 on the phosphorylation level of S892.
[Methods] pCDH-CMV-MCS-EF1copGFP-PP5 was prepared, packaged in lentivirus, and infected with HEK293 cells. The PP5 and R2 genes were simultaneously introduced into HEK293 cells, and the phosphorylation level of S892 was confirmed by Western blotting.
[Results] Virus packaging of the R2 gene was confirmed, but sufficient infection was not obtained. On the other hand, when PP5 and R2 were transiently co-expressed in HEK293 cells, a decrease in the phosphorylation level of S892 was confirmed in the PP5 overexpression group.
[Conclusion] If the detailed function of internalization or inactivation mediated by GABAB receptor dephosphorylation due to overexpression of PP5 is clarified, multiple sclerosis and amyotrophic lateral sclerosis associated with GABAB receptors will be clarified. It may lead to detailed elucidation of pathological conditions such as sclerosis and development of new therapeutic agents.