Regular initiation of translation of Plasmodium berghei aldolase-2 after pre-mRNA splicing

In Plasmodium falciparum aldolase a UAG or a regular AUG codon has been proposed for the initiation of ribosomal protein synthesis. A UAG codon present at the beginning of the coding sequence of the aldolase 2 gene (aldo-2) of Plasmodium berghei is not recognised in vitro as an initiation codon, which suggests addition of a regular AUG codon by mRNA splicing. Sequence analysis of cDNA amplified by the reversed polymerase chain reaction reveals addition of an ATG codon with a splice donor consensus sequence to the aldo-2 exon. By the same technique and northern blot analysis, substantial amounts of partially spliced P. berghei aldo-2 precursor mRNA are detected which could explain the isolation of immature P. falciparum aldolase cDNA clones starting with a stop codon.