Where did apicoplast originate?
(a) Where did the apicoplast come from? The apicoplast is clearly of secondary endosymbiotic origin, which refers to one eukaryote having engulfed and retained another eukaryote with a plastid obtained by primary endosymbiosis of a cyanobacterium-like prokaryote.
What is the meaning of apicoplast?
An apicoplast is a derived non-photosynthetic plastid found in most Apicomplexa, including Toxoplasma gondii, Plasmodium falciparum and other Plasmodium spp. (parasites causing malaria), but not in others such as Cryptosporidium.
What is apicoplast in Plasmodium?
Apicoplast, a nonphotosynthetic plastid derived from secondary symbiotic origin, is essential for the survival of malaria parasites of the genus Plasmodium. Elucidation of the evolution of the apicoplast genome in Plasmodium species is important to better understand the functions of the organelle.
Does apicoplast have DNA?
Like mitochondria and chloroplasts, apicoplasts contain their own DNA. When scientists analyzed apicoplast DNA, they were surprised to learn that apicoplasts shared sequence similarities with plastids (organelles found in the cells of photosynthetic organisms like algae and plants).
Why is apicoplast important?
The apicoplast plays a vital role in lipid metabolism. Several enzymes of fatty-acid synthesis are encoded in the nucleus but translocated into the apicoplast where fatty-acid synthesis occurs.
How many membranes does an apicoplast have?
four membranes
The Plasmodium apicoplast possesses four membranes, as do the apicoplasts of other apicomplexan parasites. This is consistent with a four-membraned secondary endosymbiotic plastid ancestor.
What do micronemes do?
Micronemes are located on the apical third of the protozoan body. They are surrounded by a typical unit membrane. On electron microscopy they have an electron-dense matrix due to the high protein content. They are specialized secretory organelles important for host-cell invasion and gliding motility.
What are Rhoptries and Micronemes?
A rhoptry is a specialized secretory organelle. They are club-shaped organelles connected by thin necks to the extreme apical pole of the parasite. These organelles, like micronemes, are characteristic of the motile stages of Apicomplexa protozoans.
What do Micronemes do in Plasmodium?
The derived microneme proteome contains proteins consistent with a eukaryotic regulated secretory pathway, together with the largest category of proteins, of unknown function, which is likely to include proteins important to host invasion.
What do Micronemes do?
What is Micronemes function?
Micronemes are involved in the trafficking and sequestration of binding ligands for host cell receptors, and ensure the appropriate release of these ligands in high concentration at the very tip of the parasite, in response to external stimuli that sense contact with the host cell surface.
What is the function of Rhoptry?
Apicomplexan parasites use actin-based motility coupled with regulated protein secretion from apical organelles to actively invade host cells. Critical in this process are rhoptries, club-shaped secretory organelles that discharge their contents during parasite invasion into host cells.