Cell death in protists without mitochondria.
Some protozoans, such as Trichomonad species, do not possess mitochondria. Most of the time, they harbor another type of membrane-bounded organelle, called hydrogenosome from its capacity to produce H(2). This is the case for the human parasite Trichomonas vaginalis. Some other parasites, such as the protist Giardia lamblia, do not harbor any of these organelles. From this observation arises naturally a naive question: How do cells die when the mitochondrion, the cornerstone of apoptotic process, is absent? Data strongly suggest that the mitochondrion and the hydrogenosome arose from a common ancestral endosymbiont. But hydrogenosomes do not appear to directly substitute for mitochondria in apoptotic functions. Thus, it appears judicious to examine more closely the genome of unicellular cells, which do not harbor mitochondria, and search for new molecules that could participate in the apoptotic process in these microorganisms.
Chose
Olivier
O
Laboratoire de Génie Enzymatique et Cellulaire, UMR CNRS 6022, Université de Technologie de Compiegne, B.P. 20529, 60205 Compiègne Cedex, France.
Sarde
Claude-Olivier
CO
Noël
Christophe
C
Gerbod
Delphine
D
Jimenez
Juan-Carlos
JC
Brenner
Catherine
C
Capron
Monique
M
Viscogliosi
Eric
E
Roseto
Alberto
A
D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D016923:Cell Death / Q000502:physiology*; D056890:Eukaryota / Q000502:physiology* / Q000648:ultrastructure; D016829:Giardia lamblia / Q000166:cytology / Q000502:physiology; D006801:Humans; D006859:Hydrogen / Q000378:metabolism; D008928:Mitochondria / Q000502:physiology*; D013559:Symbiosis; D014246:Trichomonas vaginalis / Q000166:cytology / Q000502:physiology
D006859:Hydrogen