Apicomplexa

Perkins, F. O. (1991), Sporozoa Apicomplexa, Microsporidia, Haplosporidia, Paramyxea, Myx-osporidia and Actinosporidia, in F. W. Harrison andj. O. Corliss (Eds), Microscopic Anatomy of Invertebrates Protozoa, Vol. 1., Wiley-Liss, New York, pp. 261-331-... 

Bougdour A, Maubon D, Baldacci P, Ortet P, Bastien O, Bouillon A, Barale JC, Pelloux H, Menard R, Hakimi MA. (2009) Drug inhibition of HDAC3 and epigenetic control of differentiation in apicomplexa parasites. JExper Med 206 953-966. 

Williams BAP, Hirt RP, Lucocq JM, Embley TM (2002) A mitochondrial remnant in the microsporidian Trachipleistophora hominis. Nature 418 865-869 Wilson RJ, Williamson DH (1997) Extrachromosomal DNA in the Apicomplexa. Microbiol... 

Cryptosporidium parvum belongs to the diverse group of intracellular apicomplexans that includes species of human (Babesia microti, Plasmodium falciparum, Toxoplasma gondii) and veterinary (Eimeria tenella, Neospora caninum) importance (Ellis et al. 1998 Fayer 1997 Thompson et al. 2005). While a single mitochondrion is present in most Apicomplexa (McFadden... 

The infoldings of the mitochondrial IM also differ from those of most Apicomplexa, in which the type and number of cristae vary considerably during the life cycle, ranging from tubular in T. gondii tachyzoites (Melo et al. 

Beyer TV, Svezhova NV, Sidorenko NV, Khokhlov SE (2000) Cryptosporidium parvum (Coccidia Apicomplexa) Some new ultrastructural observations on its endogenous development. Eur J Protistol 36 151-159... 

Crawford MJ, Fraunholz MJ, Roos DS (2003) Energy metabolism in the Apicomplexa. In Marr JJ, Nielsen TW, Komuniecki RW (eds) Molecular Medical Parasitology, vol 7. Academic Press, New York, pp 154-169... 

Ellis TJ, Morrison DA, Jeffries AC (1998) The phylum Apicomplexa an update on the molecular phlogeny. In Coombs GC, Vickerman K, Sleigh MA, Warren A (eds) Evolutionary Relationships among the Protozoa. Kluwer, Boston, pp 255-274... 

Lukes J (1992) Life cycle of Goussia pannonica (Molnar 1989) (Apicomplexa, Eimerior-ina), an extracytoplasmic coccidium from the white bream Blicca bjoerkna. Proto-zool 39 484-494... 

Chromalveolata Apicomplexa Cryptosporidium EM, protein localisation See Keithly, this volume... 

Enzymes for dihydropteroate synthesis Apicomplexa Sulfones and sulfonamides... 

Dihydrofolate reductase-thymidylate synthase bifunctional enzyme Apicomplexa and Kinetoplastida Pyrimethamine... 

Mitochondrial electron transporter Apicomplexa 4-Hydroxyquinolines and 2-hydroxy-naphthoquinones... 

Intracellular protozoa of the phylum Apicomplexa such as plasmodium, toxoplasma, and eimeria have long been known to respond to sulfonamides and sulfones. This has led to the assumption that Apicomplexa must synthesize their own folate in order to survive. The reaction of 2-amino-4-hydroxy-6-hydroxymethyl-dihydropteridine diphosphate with />aminobenzoate to form 7,8-dihydropteroate has been demonstrated in cell-free extracts of the human malaria parasite Plasmodium falciparum. 2-Amino-4-hydroxy-6-hydroxymethyl-dihydropteridine pyrophosphokinase and 7,8-dihydropteroate synthase have also been identified. Sulfathiazole, sulfaguanidine, and sulfanilamide act as competitive inhibitors of p-aminobenzoate. It has not been possible to demonstrate dihydrofolate synthase activity in the parasites, which raises the possibility that 7,8-dihydropteroate may have substituted for dihydrofolate in malaria parasites. Similar lack of recognition of folate as substrate was also observed in the dihydrofolate reductase of Eimeria tenella, a parasite of chickens. 

A highly unusual feature of DHFR in Apicomplexa and Kinetoplastida is its association with thymidylate synthase in the same protein. DHFR activity is always located at the amino terminal portion, while the thymidylate synthase activity resides in the carboxyl terminal. The two enzyme functions do not appear to be interdependent eg, the DHFR portion of the P falciparum enzyme molecule was found to function normally in the absence of the thymidylate synthase portion. It is likely that since the protozoan parasites do not perform de novo synthesis of purine nucleotides, the primary function of the tetrahydrofolate produced by DHFR is to provide 5,10-methylenetetrahydrofolate only for the thymidylate synthase-catalyzed reaction. Physical association of the two enzymes may improve efficiency of TMP synthesis. If an effective means of disrupting the coordination between the two activities can be developed, this bifunctional protein may qualify as a target for antiparasitic therapy. 

Apicomplexa Protozoa Plasmodium, Toxoplasma, Malaria, coccidiosis, abortion,... 

Talevich E, Mirza A, Kannan N (2011) Structural and evolutionary divergence of eukaryotic protein kinases in Apicomplexa. BMCEvol Biol 11 321... 

Schneider AG, Mercereau-Puijalon O (2005) A new Apicomplexa-specific protein kinase family multiple members in Plasmodium falciparum, all with an export signature. BMC Genomics 6 30... 

Apicomplexa 1 ( ) M Cryptosporidium parvum AOX, PNT, IscU, IscS, Fd, MDH, Hsp60, Hsp70 PNO, Narf-like hydrogenase No... 

Cryptosporidium, like Plasmodium falciparum or Toxoplasma gondii, is an apicomplexan parasite that infects both humans and animals. Phylogenetic analyses indicate that the phylum Apicomplexa shares a common ancestor with ciliates and dinoflagellates, which form the clade Alveolata (Ellis et al. 1998 Fig. 10.2). 

T. vaginalis and other apicomplexa within the mitochondrion-bearing eukaryotes, once again suggesting a common origin of all mitochondrion-derived organelles (LaGier et al. 2003 Fig. 10.3). 

Other high molecular toxins were recorded from the Apicomplexa (Sporozoa). A protein—hyaluronic acid complex (toxotoxin) was described from peritoneal exudates of mice, which is probably produced by hosts in... 

Protista Apicomplexa Pyroplasma Pyroplasmida Babesiidae Babesia. 

Apicomplexa (Alveolata) Cryptosporidium hominis Monoxenous (apparently human specific) Yes Yes Human-to-human contact... 

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