Transcriptional mapping and RNA processing of the Plasmodium falciparum mitochondrial mRNAs

The Highly Reduced and Fragmented Mitochondrial Genome of the Early-branching Dinoflagellate Oxyrrhis marina Shares Characteristics with both Apicomplexan and Dinoflagellate Mitochondrial Genomes

“…We have therefore examined the mitochondrial genome structure and expression in Oxyrrhis marina, a marine predator that represents an ancient branch of the dinoflagellate lineage. 25,26 We have carried out a large scale EST sequencing project on O. marina and, taking advantage of the oligoadenylation of mitochondrial transcripts in apicomplexans 27,28 and dinoflagellates (mitochondrial transcripts appear in poly(A) selected libraries from other EST projects 29,30 ), identified a large number of transcripts from the mitochondrial genome. We also generated comparable information from genomic DNA and analysed mRNA endpoints in circularized mRNAs, showing that the O. marina genome has fewer protein coding units that any other genome known (two cox1 and a cob-cox3 fusion), it lacks RNA editing, contains highly fragmented rRNAs, and protein-coding genes are found in multiple but limited genomic contexts.…”

Global analysis of transcript and protein levels across the Plasmodium falciparum life cycle

“…In addition, a bioinformatic survey of transcription-associated proteins (TAPs) present in the P. falciparum genome indicated that TAPs are much less abundant in P. falciparum compared with other eukaryotic organisms, but proteins modulating mRNA decay and translation were the most abundant TAPs detected in the genome (Coulson et al 2004). The presence of these RNA-binding proteins indicates that mechanisms of post-transcriptional control should be expected in P. falciparum, and post-transcriptional regulation has been described for genes involved in sexual differentiation (Vervenne et al 1994;Dechering et al 1997), mitochondrial RNA processing (Rehkopf et al 2000), and the stability of RNAs encoding surface antigens (Lanzer et al 1993;Levitt et al 1993).…”

Translation in Mitochondria and Apicoplasts of Apicomplexan Parasites

“…Translation is initiated on the AUG codon in apicoplast-encoded mRNAs. On the other hand, AUG is used only for the cytb gene in Plasmodium mitochondrial translation while AUA and AUU are the initiation codons for coxI and coxIII genes (Kairo et al 1994;Feagin 1992;Rehkopf et al 2000). The assembly of the mRNA and 30S ribosomal subunit is not promoted through complementary base pairing of the purine-rich ShineDalgarno (SD) sequence (Shine and Dalgarno 1975) with the 16S rRNA, as the SD sequence is not conserved in organellar mRNAs of apicomplexan parasites.…”