Stimulator of ATPase activity of molecular chaperones of the HSP70 family (principally of the SSA class). Stimulation is important for HSP70-substrate complex dissociation after folding of newly synthesized or refolded proteins. SNL1 is probably involved in nuclear pore biogenesis and in particular the folding or refolding of misfolded NUP116, GLE2 and NIC96. Interacts with the HSP70 family members SSA1, SSA4, and SSB1. These interactions are strongly reduced by ADP and ATP. Present with 3346 molecules/cell in log phase SD medium.