Behavior of DNA-lacking mitochondria in Entamoeba histolytica revealed by organelle transplant

Abstract

The anaerobic protozoan parasite Entamoeba histolytica has mitosomes that are mitochondria lacking some canonical functions and organelle DNA. Mitosomes play an important role in the life cycle of the parasite. The distribution of proteins in mitosomes is not uniform, and how mitosomes are maintained and retained is unknown. To answer these questions, we developed a transplant method for mitosomes with hemagglutinin-tagged protein into recipient cells containing mitosomes with Myc-tagged protein. Immunofluorescence staining showed that the two protein tags colocalized in single mitosomes in some recipient cells. These results suggest that our transplant method can be used in anaerobic protozoa and that donor mitosomes may obtain recipient proteins through fusion with other mitosomes or through de novo synthesis of proteins in recipient cells.

Influence of Heterologous Transplant of DNA‐lacking Mitochondria from Entamoeba histolytica on Proliferation of Entamoeba invadens

“…After microinjection of the mitosome fraction into trophozoites of E. invadens , the injected solution is visible as vacuole‐like structure with different cytosol transparency in the recipient cell, as described in a previous study (Kazama et al. ) and shown in Fig. .…”

“…Transplant efficacy under these conditions was 23.5% (percentage of positive cells among all examined cells) within 30 min after injection (Kazama et al. ). In this study, transplant with mitosomes between E. histolytica expressing APSK‐HA (donor) and E. invadens IP1 (recipient) under the same conditions had efficacy of 8.6% (Table ).…”

“…) with modifications (Kazama et al. ). Briefly, 0.5–1.0 × 10 8 trophozoites were washed three times with PBS containing 2% glucose.…”

“…A recipient cell was held on the tip of the pipette and microinjected immediately with 9.0–11.0 psi injection pressure of nitrogen gas for 2 s for a single microinjection of volume 0.28–0.75 pl (Kazama et al. ). Microinjections were carried out at 4°C, 10 °C, and room temperature (24–26 °C).…”

“…), and we have established transplant of mitosomes by microinjection and used this method between different strains of E. histolytica (Kazama et al. ). Here, we use this approach with some modifications to transplant mitosomes from E. histolytica into another species of Entamoeba .…”