Acts as a component of the WASH core complex that functions as a nucleation-promoting factor (NPF) at the surface of endosomes, where it recruits and activates the Arp2/3 complex to induce actin polymerization, playing a key role in the fission of tubules that serve as transport intermediates during endosome sorting (By similarity). Acts as a component of the DHIC (ddl-1-containing hsf-1 inhibitory complex) which modulates lifespan by sequestering the heat shock transcription factor hsf-1 to negatively regulate its binding to DNA and its transcriptional activity (PubMed:22265419). Component of the WASH core complex (By similarity). Component of the DHIC (ddl-1-containing hsf-1 inhibitory) complex, which contains at least ddl-1, ddl-2, hsb-1 and hsf-1 (PubMed:22265419). Within the complex, interacts with ddl-1 (PubMed:22265419). Formation of the DHIC may be dependent upon the Insulin/IGF-1-like signaling (IIS) mediated pathway (PubMed:22265419). Expressed in several neurons located throughout the body. RNAi-mediated knockdown positively modulates lifespan; effect abolished in hsf-1 mutant background (PubMed:22265419). Increases resistance to both heat and oxidative stresses (PubMed:22265419). Increases localization to the nucleus and also DNA binding activity of heat-shock transcription factor hsf-1 after heat shock (PubMed:22265419). Increases in transcript levels of heat shock protein genes sim-1, hsp-70, hsp-16.2 and F44E5.5 after heat shock, but not in unstressed conditions (PubMed:22265419). May also moderately decrease levels of post-translationally modified hsf-1 under heat stressed conditions (PubMed:22265419). Belongs to the WASH1 family.