Nuclear transport receptor that mediates nuclear import of proteins, and which is involved in sister chromatid cohesion (PubMed:11311162, PubMed:12221121, PubMed:30563860). Binds specifically and directly to substrates containing either a simple or bipartite nuclear localization signals (NLS) motif (By similarity). Promotes docking of import substrates to the nuclear envelope (By similarity). Together with akir-1 adapter, required for the import and load of cohesin complex proteins in meiotic nuclei (PubMed:30563860). Forms a complex with an importin beta subunit (PubMed:11311162). Interacts with akir-1 (PubMed:30563860). In interphase germ cells and embryonic cells, localizes to the cytoplasm and nuclear envelope, whereas in developing oocytes, it localizes in the cytoplasm and nucleus. Germline tissues (PubMed:11311162, PubMed:12221121). Expressed exclusively in germ line cells from the early embryonic through adult stages (PubMed:12221121). Expressed weakly in early larvae, levels of expression increase in larval stage 4 and adult stages when germ cells are continually proliferating. Embryonic lethality associated with a terminal aneuploid phenotype: embryos display severe defects in nuclear envelope formation, accumulating nucleoporins and lamin in the cytoplasm (PubMed:12221121). Worms lacking both akir-1 and ima-2 show reduced gonad size and aberrant diakinesis oocyte formation; defects are caused by impaired meiotic recombination (PubMed:30563860). Belongs to the importin alpha family.