E3 SUMO-protein ligase (By similarity). Component of the nuclear pore complex (NPC), a complex required for trafficking across the nuclear envelope (PubMed:17682050). Required for nuclear import of nuclear localization signal (NLS)-containing proteins in an importin alpha/importin beta-dependent manner, but also for the nuclear import of specific proteins such as phosphorylated Mad or the sesquiterpenoid juvenile hormone receptor Met as part of the juvenile hormone signal transduction pathway (PubMed:27979731, PubMed:17682050, PubMed:17682050). Plays a role in nuclear mRNA export by recruiting the mRNA transport complex composed of Nxt1 and sbr/Nxf1 to the NPC (PubMed:14729961). Essential during germline development for transposon silencing and piRNA biogenesis probably by regulating piwi localization to the nucleus (PubMed:29735528). During oogenesis, required to form granules that modulate the biogenesis of annulate lamellae containing nuclear pore complex components (PubMed:31626769). Part of the nuclear pore complex (By similarity). Forms a complex with Nxt1, sbr/Nxf1 and RanGAP (PubMed:14729961). Interacts (via TPR repeats) with Hsp83; the interaction is required for the nuclear import of the sesquiterpenoid juvenile hormone receptor Met (PubMed:27979731). Interacts (via N-terminus) with piwi (PubMed:29735528). Localizes to annulate lamellae, stacked membrane sheets of the endoplasmic reticulum. Localizes to granules which travel from nurse cells into the ooplasm through ring canals connecting the cytoplasm of the two cell types. Expressed in both oocytes and nurse cells (at protein level). Expressed during embryogenesis (at protein level). Contains FG repeats. FG repeats are interaction sites for karyopherins (importins, exportins) and form probably an affinity gradient, guiding the transport proteins unidirectionally with their cargo through the NPC. FG repeat regions are highly flexible and lack ordered secondary structure. The overall conservation of FG repeats regarding exact sequence, spacing, and repeat unit length is limited. RNAi-mediated knockdown abolishes embryonic development (PubMed:31626769). RNAi-mediated knockdown in the larval fat body reduces the levels of importin beta and disrupts the nuclear import of the sesquiterpenoid juvenile hormone receptor Met and juvenile hormone signal transduction (PubMed:27979731). RNAi-mediated knockdown in the germarium results in failed piwi localization to the nucleus, failed transposon silencing and piRNA biogenesis, increased DNA damage levels and overall defective ovaries (PubMed:29735528). RNAi-mediated knockdown in egg chambers reduces numbers of annulate lamellae containing nuclear pore complex components (PubMed:31626769). Belongs to the RanBP2 E3 ligase family. Truncated N-terminus.