LLPS mediates assembly of protein condensates for selective autophagy. (A) Weak multivalent interactions between Ape1 dodecamers induce LLPS to form gel-like Ape1 condensates. Atg19 is localized at the condensate surface. Autophagosome formation proceeds along the surface of the condensates using the Atg8–Atg19 interaction. In the case of the Ape1 P22L mutant, strong multivalent interactions cause aggregation of Ape1 with little liquidity, and autophagosome formation does not proceed. (B) Schematic illustration showing the degradation of oocyte-loaded PGL-1/PGL-3 by autophagy in somatic cells. SEPA-1 and EPG-2 are zygotically synthesized, and their levels exhibit temporal variation. P1 and P2 are germline blastomeres. Z2 and Z3 are germline precursor cells derived from the germline blastomere P4. Z2 and Z3 remain quiescent during embryogenesis. (C) Phase separation and transition control autophagic degradation or accumulation of PGL granules under different growth conditions. The concerted actions of SEPA-1 and EPG-2, together with EPG-11– and LET-363–mediated modifications of PGL-1 and PGL-3, ensure that the assembly rate, size, and material state of PGL granules are coordinated with autophagic flux during embryogenesis. Under heat stress conditions, this combination of enhanced PGL granule assembly and normal EPG-2 degradation result in insufficient EPG-2 to render PGL granules amenable to degradation.