The Schizosaccharomyces pombe Hikeshi/Opi10 protein has similar biochemical functions to its human homolog but acts in different physiological contexts

• SpHikeshi/Opi10 interacts with the S. pombe Hsp70 homolog Ssa2.
• SpHikeshi/Opi10 imports Ssa2 in a HeLa-reconstituted nuclear transport system.
• SpHikeshi/Opi10 is not required for cell survival in S. pombe after heat stress.
• SpHikeshi/Opi10 depletion affects gene expression under optimal conditions.
• SpHikeshi/Opi10 is required for cell growth in S. pombe during glucose deprivation.

Human Hikeshi (HsHikeshi) is a nuclear import carrier for Hsp70s and is required for cell survival after heat shock. The Hikeshi homolog in Schizosaccharomyces pombe (SpHikeshi/Opi10) localizes to the nuclear rim, interacts with the Hsp70 homolog Ssa2, and mediates its nuclear import in a reconstituted mammalian nuclear transport system. However, SpHikeshi/Opi10 is not required for heat stress response and survival after heat stress. Instead, SpHikeshi/Opi10 is required for the normal expression of stress response genes under optimal conditions and for cell growth during glucose deprivation. Here, the functions of SpHikeshi/Opi10 are discussed and compared to the functions of HsHikeshi.

Structured summary of protein interactionsSpHikeshi/Opi10physically interacts with Ssa1 by anti tag coimmunoprecipitation (View interaction)SpHikeshi/Opi10physically interacts with Ssa2 by anti tag coimmunoprecipitation (View interaction)