A metacaspase of <i>Trypanosoma brucei</i> causes loss of respiration competence and clonal death in the yeast <i>Saccharomyces cerevisiae</i>

Szallies, Alexander; Kubata, Bruno Kilunga; Duszenko, Michael

doi:10.1016/s0014-5793(02)02608-x

Cited by 129 publications

(112 citation statements)

References 43 publications

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“…Recently it has been suggested that the actD gene, MXAN3216, is a cysteine protease homolog that belongs to clan CD, which includes family C14 of caspase-like enzymes EC 3.4.22.36 and which is directed toward particular proteins (1,4,63,65). Members of this family have a His/Cys catalytic dyad around which sequence is conserved.…”

Section: Discussionmentioning

confidence: 99%

Mutations of the Act Promoter in Myxococcus xanthus

Gronewold

Kaiser

2007

J Bacteriol

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Mutations within the ؊12 and ؊24 elements provide evidence that the act promoter is recognized by sigma-54 RNA polymerase. Deletion of the ؊20 base pair, which lies between the two conserved elements of sigma-54 promoters, decreased expression by 90%. In addition, mutation of a potential enhancer sequence, around ؊120, led to an 80% reduction in act gene expression. actB, the second gene in the act operon, encodes a sigma-54 activator protein that is proposed to be an enhancer-binding protein for the act operon. All act genes, actA to actE, are expressed together and constitute an operon, because an in-frame deletion of actB decreased expression of actA and actE to the same extent. After an initially slow phase of act operon expression, which depends on FruA, there is a rapid phase. The rapid phase is shown to be due to the activation of the operon expression by ActB, which completes a positive feedback loop. That loop appears to be nested within a larger positive loop in which ActB is activated by the C signal via ActA, and the act operon activates transcription of the csgA gene. We propose that, as cells engage in more C signaling, positive feedback raises the number of C-signal molecules per cell and drives the process of fruiting body development forward.

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Section: Discussionmentioning

confidence: 99%

Mutations of the Act Promoter in Myxococcus xanthus

Gronewold

Kaiser

2007

J Bacteriol

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“…Modeling of the threedimensional protein structure of para-and metacaspases indicates significant tertiary structure homology to animal caspases (the so-called caspasehemoglobinase fold). Mutational studies in Trypanosoma brucei first suggested that metacaspases function as Cys proteinases (Scallies et al, 2002). It was recently shown that the only metacaspase present in Brewer's yeast (Saccharomyces cerevisiae) displays caspase-like proteolytic activity that is activated when yeast is stimulated by H 2 O 2 to undergo apoptosis (Madeo et al, 2002).…”

Section: Caspase Tertiary Structurementioning

confidence: 99%

Do Plant Caspases Exist?

2002

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“…Presumably, early ancestors of plants and animals had minimal apoptotic machinery, with the more complex PCD systems emerging with the evolution of metazoans. Whereas most metacaspase genes have only been characterized in silico, their genetic signatures have been directly linked to caspase activity and the mediation of PCD in yeast (20) and trypanosomes (21). Metacaspases are also essential for PCD execution in plants despite possessing an altered substrate specificity compared with canonical caspases (22,23).…”

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confidence: 99%