#4085 POLY(ADP-RIBOSE) POLYMERASE 1 AFFECTS THE VASOPRESSIN-MEDIATED AQP2 EXPRESSION VIA AN INTERACTION WITH BETA-CATENIN

Abstract Background and Aims Poly(ADP-ribosy)lation (PARylation), which is mediated by poly(ADP-ribose) polymerases (PARPs), catalyzes the transfer of ADP-ribose from NAD+ molecules to acceptor proteins, regulates diverse cellular processes. Since PARP1 gene-deficient mice revealed an increase in urine volume, we aimed examine role PARP1, most abundant type protein PARPs family, vasopressin-mediated AQP2 regulation. Method 1) Immunoblotting for mpkCCDc14 cells; 2) Pulldown assay biotin-conjugated immunoprecipitation (IP) using (PAR) antibody; 3) qRT-PCR immunoblotting AQP2; 4) Bioinformatics elucidating PARP1-interacting proteins kidney collecting duct (CD) cells. Results Immunoblots showed that dDAVP treatment (10−9 M, 2 h, 6 24 48 h) induced cleavage (both 89 kDa 25 kDa) also increased abundance total PARylated biotin-NAD+ pulldown IP PAR On other hand, siRNA-mediated knockdown significantly attenuated dDAVP-induced mRNA abundance, suggesting a was not changed under knockdown, indicating unlikely be involved In contrast inhibitor (PJ34) did reduce despite significant decrease PARylation. The results suggest dDAVP-regulated expression associated with per se, but PARP1-mediated study 408 interact CD Among them, 49 were mapped on vasopressin V2 receptor (V2R) signaling pathway. particular, β-catenin, phosphorylated (S552) dDAVP, identified as V2R signaling. demonstrated decreased phosphorylation β-catenin at S552 Conclusion likely play regulation via interaction rather than PARylation and/or