Limits...
ATG8 localization in apicomplexan parasites: apicoplast and more?

Mizushima N, Sahani MH - Autophagy (2014)

Bottom Line: In contrast to this established localization, it remains unclear whether these parasites can induce canonical macroautophagy and if ATG8 localizes to autophagosomes.Furthermore, the molecular function of ATG8 in its novel workplace, the apicoplast, is totally unknown.Here, we review recent studies on ATG8 in Plasmodium and Toxoplasma, summarize both consensus and controversial findings, and discuss its potential role in these parasites.

View Article: PubMed Central - PubMed

Affiliation: Department of Biochemistry and Molecular Biology; Graduate School and Faculty of Medicine; University of Tokyo; Tokyo, Japan.

ABSTRACT
The ATG genes are highly conserved in eukaryotes including yeasts, plants, and mammals. However, these genes appear to be only partially present in most protists. Recent studies demonstrated that, in the apicomplexan parasites Plasmodium (malaria parasites) and Toxoplasma, ATG8 localizes to the apicoplast, a unique nonphotosynthetic plastid with 4 limiting membranes. In contrast to this established localization, it remains unclear whether these parasites can induce canonical macroautophagy and if ATG8 localizes to autophagosomes. Furthermore, the molecular function of ATG8 in its novel workplace, the apicoplast, is totally unknown. Here, we review recent studies on ATG8 in Plasmodium and Toxoplasma, summarize both consensus and controversial findings, and discuss its potential role in these parasites.

Show MeSH

Related in: MedlinePlus

Figure 3. PfATG8 and TgATG8 localize to apicoplasts. Localization of PfATG8 in early schizonts (the multinucleated replicating form inside a host cell; upper), late schizonts (middle), and merozoites (daughter cells within the host formed by division of the schizont; lower) (A) and TgATG8 in tachyzoites (B) are shown together with apicoplast (Apico) markers. The arrowhead indicates a putative autophagosome. Scale bars: 5 μm. The images in (A and B) were published in references 14,28, respectively, with permission of the publisher.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4206529&req=5

Figure 3: Figure 3. PfATG8 and TgATG8 localize to apicoplasts. Localization of PfATG8 in early schizonts (the multinucleated replicating form inside a host cell; upper), late schizonts (middle), and merozoites (daughter cells within the host formed by division of the schizont; lower) (A) and TgATG8 in tachyzoites (B) are shown together with apicoplast (Apico) markers. The arrowhead indicates a putative autophagosome. Scale bars: 5 μm. The images in (A and B) were published in references 14,28, respectively, with permission of the publisher.

Mentions: Immunofluorescence microscopy shows that endogenous PfATG8,13,14,20,21,25 GFP/mCherry-PfATG8,14,25 endogenous PbATG8,23 green fluorescent protein (GFP)-PbATG8,23 endogenous TgATG8,28 and GFP-TgATG827,28 constitutively colocalize with apicoplast markers such as acyl carrier protein and apicoplast lipoamide dehydrogenase-GFP in Plasmodium and ATRX1 in Toxoplasma (Fig. 3). Electron microscopy also detects endogenous PfATG8 and PbATG8 signals on apicoplasts, most likely on the outermost membrane of the 4 apicoplast membranes.13,20


ATG8 localization in apicomplexan parasites: apicoplast and more?

Mizushima N, Sahani MH - Autophagy (2014)

Figure 3. PfATG8 and TgATG8 localize to apicoplasts. Localization of PfATG8 in early schizonts (the multinucleated replicating form inside a host cell; upper), late schizonts (middle), and merozoites (daughter cells within the host formed by division of the schizont; lower) (A) and TgATG8 in tachyzoites (B) are shown together with apicoplast (Apico) markers. The arrowhead indicates a putative autophagosome. Scale bars: 5 μm. The images in (A and B) were published in references 14,28, respectively, with permission of the publisher.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4206529&req=5

Figure 3: Figure 3. PfATG8 and TgATG8 localize to apicoplasts. Localization of PfATG8 in early schizonts (the multinucleated replicating form inside a host cell; upper), late schizonts (middle), and merozoites (daughter cells within the host formed by division of the schizont; lower) (A) and TgATG8 in tachyzoites (B) are shown together with apicoplast (Apico) markers. The arrowhead indicates a putative autophagosome. Scale bars: 5 μm. The images in (A and B) were published in references 14,28, respectively, with permission of the publisher.
Mentions: Immunofluorescence microscopy shows that endogenous PfATG8,13,14,20,21,25 GFP/mCherry-PfATG8,14,25 endogenous PbATG8,23 green fluorescent protein (GFP)-PbATG8,23 endogenous TgATG8,28 and GFP-TgATG827,28 constitutively colocalize with apicoplast markers such as acyl carrier protein and apicoplast lipoamide dehydrogenase-GFP in Plasmodium and ATRX1 in Toxoplasma (Fig. 3). Electron microscopy also detects endogenous PfATG8 and PbATG8 signals on apicoplasts, most likely on the outermost membrane of the 4 apicoplast membranes.13,20

Bottom Line: In contrast to this established localization, it remains unclear whether these parasites can induce canonical macroautophagy and if ATG8 localizes to autophagosomes.Furthermore, the molecular function of ATG8 in its novel workplace, the apicoplast, is totally unknown.Here, we review recent studies on ATG8 in Plasmodium and Toxoplasma, summarize both consensus and controversial findings, and discuss its potential role in these parasites.

View Article: PubMed Central - PubMed

Affiliation: Department of Biochemistry and Molecular Biology; Graduate School and Faculty of Medicine; University of Tokyo; Tokyo, Japan.

ABSTRACT
The ATG genes are highly conserved in eukaryotes including yeasts, plants, and mammals. However, these genes appear to be only partially present in most protists. Recent studies demonstrated that, in the apicomplexan parasites Plasmodium (malaria parasites) and Toxoplasma, ATG8 localizes to the apicoplast, a unique nonphotosynthetic plastid with 4 limiting membranes. In contrast to this established localization, it remains unclear whether these parasites can induce canonical macroautophagy and if ATG8 localizes to autophagosomes. Furthermore, the molecular function of ATG8 in its novel workplace, the apicoplast, is totally unknown. Here, we review recent studies on ATG8 in Plasmodium and Toxoplasma, summarize both consensus and controversial findings, and discuss its potential role in these parasites.

Show MeSH
Related in: MedlinePlus