Control mechanisms of the H2A genes expression in Trypanosoma cruzi.
In a previous report we have described that the T. cruzi histone H2A gene is encoded in two independent gene clusters located in a single chromosome. In the present paper we show that both gene cluster are actively transcribed as two sized classes of polyadenylated mRNAs demonstrating, moreover, the existence of alternative splicing sites and microheterogeneities at the polyadenylation site. We also describe that while the expression of the H2A genes in the non replicative trypomastigote forms is only residual, in the replicative forms there is constitutive transcription of these genes and that the transcription is not associated to DNA replication. The data show, moreover, that in the replicative forms the steady state levels of the H2A mRNAs are controlled at a post-transcriptional level which is associated to DNA replication.
Marañón
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Instituto de Parasitología y Biomedicina López Neyra, Consejo Superior de Investigaciones Científicas, Granada, Spain.
Puerta
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Alonso
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López
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D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003513:Cycloheximide / Q000494:pharmacology; D004251:DNA Transposable Elements; D016054:DNA, Protozoan / Q000096:biosynthesis; D005786:Gene Expression Regulation; D006657:Histones / Q000235:genetics*; D008969:Molecular Sequence Data; D005810:Multigene Family; D011401:Promoter Regions, Genetic; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D015800:Protozoan Proteins / Q000235:genetics*; D012326:RNA Splicing; D012333:RNA, Messenger / Q000378:metabolism; D016415:Sequence Alignment; D014158:Transcription, Genetic / Q000187:drug effects; D014349:Trypanosoma cruzi / Q000187:drug effects / Q000235:genetics*
D004251:DNA Transposable Elements; D016054:DNA, Protozoan; D006657:Histones; D011500:Protein Synthesis Inhibitors; D015800:Protozoan Proteins; D012333:RNA, Messenger; D003513:Cycloheximide