PROHIBITIN AND RACK HOMOLOGS ARE UP-REGULATED IN TRYPANOSOMES INDUCEDTO UNDERGO APOPTOSIS AND IN NATURALLY-OCCURRING TERMINALLY DIFFERENTIATED FORMS

Two genes have been identified as up-regulated late during ConA-induce d apoptosis in procyclic form Trypanosoma brucei rhodesiense, The firs t represents a homologue of prohibitin, a proto oncogene originally de scribed in mammals and subsequently in yeast, which is involved in cel l-cycle control and senescence. The Trypanosoma prohibitin homologue a ppears to contain within it a putative death domain. The second gene, homologous to a family of regulatory proteins which are receptors for activated protein kinase C (RACKs), is also shown to be up-regulated i n terminally differentiated bloodstream form trypanosomes. These are t he first endogenous genes to be identified as upregulated in programme d cell death (PCD) in unicellular organisms.