Conservation and developmental control of alternative splicing in maebl among malaria parasites.
Genes of malaria parasites and other unicellular organisms have larger exons with fewer and smaller introns than metaozoans. Such differences in gene structure are perceived to extend to simpler mechanisms for transcriptional control and mRNA processing. Instead, we discovered a surprisingly complex level of post-transcriptional mRNA processing in analysis of maebl transcripts in several Plasmodium species. Mechanisms for internal alternative cis-splicing and exon skipping were active in multiple life cycle stages to change exon structure in the deduced coding sequence (CDS). The major alternatively spliced transcript utilized a less favorable acceptor splice site, which shifted codon triplet usage to a different CDS with a hydrophilic C terminus, changing the canonical type I membrane MAEBL product to a predicted soluble isoform. We found that developmental control of the alternative splicing pattern was distinct from the canonical splicing pattern. Western blot analysis indicated that MAEBL expression was better correlated with the appearance of the canonical ORF1 transcript. Together these data reveal that RNA metabolism in unicellular eukaryotes like Plasmodium is more sophisticated than believed and may have a significant role regulating gene expression in Plasmodium.
Department of Biological Sciences, University of Notre Dame, 220 Galvin, PO Box 369, Notre Dame, IN 46556, USA.
Naresh
N
Singh
Peter
P
Preiser
Laurent
L
Rénia
Bharath
B
Balu
John
J
Barnwell
Peter
P
Blair
William
W
Jarra
Tatiana
T
Voza
Irène
I
Landau
John H
JH
Adams
D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003062:Codon; D005091:Exons; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D010963:Plasmodium falciparum / Q000235:genetics* / Q000378:metabolism; D010966:Plasmodium vivax / Q000235:genetics* / Q000378:metabolism; D010967:Plasmodium yoelii / Q000235:genetics* / Q000378:metabolism; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D015800:Protozoan Proteins / Q000235:genetics* / Q000378:metabolism*; D012323:RNA Processing, Post-Transcriptional; D016053:RNA, Protozoan / Q000235:genetics / Q000378:metabolism*; D011956:Receptors, Cell Surface / Q000235:genetics* / Q000378:metabolism*; D016415:Sequence Alignment
D003062:Codon; C468522:MAEBL protein, Plasmodium falciparum; D020033:Protein Isoforms; D015800:Protozoan Proteins; D016053:RNA, Protozoan; D011956:Receptors, Cell Surface