Douglas J Lacount

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Plasmodium falciparum causes the most severe form of malaria and kills up to 2.7 million people annually. Despite the global importance of P. falciparum, the vast majority of its proteins have not been characterized experimentally. Here we identify P. falciparum protein-protein interactions using a high-throughput version of the yeast two-hybrid assay that(More)
Dengue virus (DENV) modifies cellular membranes to establish its sites of replication. Although the 3D architecture of these structures has recently been described, little is known about the cellular pathways required for their formation and expansion. In this report, we examine the host requirements for DENV replication using a focused RNAi analysis(More)
The single flagellum of the protozoan parasite Trypanosoma brucei is attached along the length of the cell body by a complex structure that requires the FLA1 protein. We show here that inhibition of FLA1 expression by RNA interference in procyclic trypanosomes causes flagellar detachment and prevents cytokinesis. Despite being unable to divide, these cells(More)
The discovery of double-stranded RNA interference (dsRNAi) in Trypanosoma brucei provides a convenient method to generate knockout phenotypes in this protozoan parasite [Ngo H, Tschudi C, Gull K, Ullu E. Double-stranded RNA induces mRNA degradation in Trypanosoma brucei. Proc Natl Acad Sci USA 1998;95:14687-14692]. The presence of double-stranded RNA(More)
Members of the inhibitor of apoptosis (iap) gene family prevent programmed cell death induced by multiple signals in diverse organisms, suggesting that they act at a conserved step in the apoptotic pathway. To investigate the molecular mechanism of iap function, we expressed epitope-tagged Op-iap, the prototype viral iap from Orgyia pseudotsugata nuclear(More)
Expression of the apoptosis suppressor gene p35, derived from the baculovirus Autographa californica nuclear polyhedrosis virus, markedly inhibited the cell death of stably transfected mammalian neural cells whether the cell death was induced by glucose withdrawal, calcium ionophore, or serum withdrawal. The p35 protein, which is required to block(More)
The genome of the African trypanosome Trypanosoma brucei (Tb) contains at least three gene families (TbMSP-A, -B, and -C) encoding homologues of the abundant major surface protease (MSP, previously called GP63), which is found in all Leishmania species. TbMSP-B mRNA occurs in both procyclic and bloodstream trypanosomes, whereas TbMSP-A and -C mRNAs are(More)
Baculovirus p35 prevents programmed cell death in diverse organisms and encodes a protein inhibitor (P35) of the CED-3/interleukin-1 beta-converting enzyme (ICE)-related proteases. By using site-directed mutagenesis, we have identified P35 domains necessary for suppression of virus-induced apoptosis in insect cells, the context in which P35 evolved. During(More)
Signal-induced activation of caspases, the critical protease effectors of apoptosis, requires proteolytic processing of their inactive proenzymes. Consequently, regulation of procaspase processing is critical to apoptotic execution. We report here that baculovirus pancaspase inhibitor P35 and inhibitor of apoptosis Op-IAP prevent caspase activation in vivo,(More)
We developed a method to co-express protein pairs from collections of otherwise identical Escherichia coli plasmids expressing different ORFs by incorporating a 61-nucleotide sequence (LINK) into the plasmid to allow generation of tandem plasmids. Tandem plasmids are formed in a ligation-independent manner, propagate efficiently, and produce protein pairs(More)