Acts as a specific nuclear import carrier for HSP70 proteins following heat-shock stress: acts by mediating the nucleoporin-dependent translocation of ATP-bound HSP70 proteins into the nucleus. HSP70 proteins import is required to protect cells from heat shock damages. Does not translocate ADP-bound HSP70 proteins into the nucleus. Forms an asymmetric homodimer; required for binding and nuclear import of HSP70 proteins (PubMed:25760597). Interacts with ATP-bound HSP70 proteins (PubMed:22541429). Interacts with NUP62 and NUP153 (via F-X-F-G repeats) (PubMed:22541429). Interacts with HSPA8 (PubMed:25760597). Following heat-shock treatment. The disease is caused by variants affecting the gene represented in this entry. 'Hikeshi' is a traditional Japanese compound word used for a firefighter, smokejumper, or troubleshooter. Belongs to the OPI10 family.