title: Stage-specific expression and genomic organization of the actin genes of the malaria parasite Plasmodium falciparum.
abstract: Two different actin transcripts are found in the human malaria parasite Plasmodium falciparum. One of these is a 2.5-kb-long RNA found both in asexual blood stages and in the sexual stages (i.e., gametes/zygotes) of the parasite. This transcript is encoded by the P. falciparum (pf)-actin I gene. The second malarial actin gene, the pf-actin II gene, yields a 1.9-kb-long transcript which is formed solely in the sexual stages. Elucidation of the genomic organisation of these two Plasmodium actin genes showed that the pf-actin I gene does not possess any introns whereas the coding region of the pf-actin II gene is interrupted by a 368-bp intron. This intron has consensus splice junction sequences. Nucleotide sequence analysis of the 3' non-coding regions of the pf-actin genes revealed that these regions are quite long (pf-actin I, 250 bp; pf-actin II, 331 bp) and that these trailers do not share sequence similarity. Furthermore, the poly(A)+ addition sites of both actin mRNAs have now been identified. The 5' untranslated regions are also rather long; the sequenced areas lack sequence similarity and have, as do the 3' untranslated regions, a very high A + T content.
authors.affiliation: Department of Molecular Biology, University of Nijmegen, The Netherlands.
authors.forename: J G
authors.initials: JG
authors.lastname: Wesseling
authors.forename: P J
authors.initials: PJ
authors.lastname: Snijders
authors.forename: P
authors.initials: P
authors.lastname: van Someren
authors.forename: J
authors.initials: J
authors.lastname: Jansen
authors.forename: M A
authors.initials: MA
authors.lastname: Smits
authors.forename: J G
authors.initials: JG
authors.lastname: Schoenmakers
mesh_terms: D000199:Actins / Q000096:biosynthesis* / Q000235:genetics; D000595:Amino Acid Sequence; D000818:Animals; D001482:Base Composition; D001483:Base Sequence; D015152:Blotting, Northern; D003062:Codon; D004247:DNA / Q000235:genetics*; D005091:Exons; D007438:Introns; D008969:Molecular Sequence Data; D010963:Plasmodium falciparum / Q000235:genetics* / Q000254:growth & development; D011061:Poly A / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D015183:Restriction Mapping
chemical_list: D000199:Actins; D003062:Codon; D012333:RNA, Messenger; D011061:Poly A; D004247:DNA