Polyamine deacetylase (PDAC), which acts preferentially on N(8)-acetylspermidine, and also on acetylcadaverine and acetylputrescine (PubMed:28516954). Exhibits attenuated catalytic activity toward N(1),N(8)-diacetylspermidine and very low activity, if any, toward N(1)-acetylspermidine (PubMed:28516954). Histone deacetylase activity has been observed in vitro (PubMed:11861901, PubMed:11726666, PubMed:11677242, PubMed:11739383). Has also been shown to be involved in MSH2 deacetylation (PubMed:26221039). The physiological relevance of protein/histone deacetylase activity is unclear and could be very weak (PubMed:28516954). May play a role in the promotion of late stages of autophagy, possibly autophagosome-lysosome fusion and/or lysosomal exocytosis in neuroblastoma cells (PubMed:23801752, PubMed:29968769). May play a role in homologous recombination (PubMed:21247901). May promote DNA mismatch repair (PubMed:26221039). H2O + N(8)-acetylspermidine = acetate + spermidine H2O + N-acetylputrescine = acetate + putrescine H2O + N-acetylcadaverine = acetate + cadaverine H2O + N(6)-acetyl-L-lysyl-[protein] = acetate + L-lysyl-[protein] Interacts with HDAC3 (PubMed:11861901). Interacts with HDAC2 and NCOR2/SMRT (PubMed:11739383). Interacts with HSPA8/HSC70 (PubMed:23801752). Interacts with MSH2 (PubMed:26221039). Excluded from nucleoli. Widely expressed with high levels in liver and kidney. In neuroblastoma cells, may promote autophagy in response to chemotherapy-induced DNA damage and efflux of chemotherapeutics via lysosomal exocytosis, hence protecting cells from cytotoxic agents (PubMed:23801752, PubMed:29968769). Expression levels may correlate with survival in neuroblastoma patients, with low levels in the tumor correlating with long-term patient survival and high expression with poor prognosis (PubMed:23801752). Therefore has been proposed as a biomarker to predict neuroblastoma chemoresistance and treatment outcome (PubMed:23801752). Like some other members of the HD type 2 subfamily, such as HDAC4, inhibited by the antitumor drug trichostatin A (TSA). May be produced at very low levels due to a premature stop codon in the mRNA, leading to nonsense-mediated mRNA decay. Belongs to the histone deacetylase family. HD type 2 subfamily. Protein/histone deacetylase activity in vivo is uncertain. The 3D structure analysis of the zebrafish ortholog shows that a glutamate gatekeeper and a sterically constricted active site confer specificity for N(8)-acetylspermidine hydrolysis and disfavour acetyllysine hydrolysis. Supporting this observation, has been shown to exhibit only very low activity, if any, towards acetyl-lysine peptide substrates (PubMed:28516954). However, histone deacetylase activity has been observed in vitro (PubMed:28516954, PubMed:11861901, PubMed:11726666, PubMed:11677242, PubMed:11739383). Has also been shown to be involved in MSH2 deacetylation (PubMed:26221039).