title: Regulated transcription of the histone H2B genes of Trypanosoma brucei.
abstract: In Trypanosoma brucei, the genes encoding histone H2B are organized in a cluster of about 10-15 tandemly linked copies per haploid genome. The H2B transcripts are processed by trans-splicing and polyadenylation, and encode a polypeptide of 111 residues with a molecular mass of 12.5 kDa. H2B mRNAs are differentially expressed during the parasite life-cycle and are present at higher levels in dividing procyclic and bloodstream slender forms than in the nondividing bloodstream stumpy forms. Analysis of H2B mRNA levels during the synchronous differentiation from stumpy to procyclics forms revealed that the abundance of these transcripts is regulated through the cell-cycle, reaching maximum levels during S-phase. Addition of hydroxyurea to procyclic forms in culture specifically decreased H2B mRNA levels by about twofold, an effect not linked to its 3' untranslated region. Inhibition of protein synthesis prevented this decrease.
authors.affiliation: Laboratory of Molecular Parasitology, Department of Molecular Biology, Free University of Brussels, Belgium. jantonio@alize.ulb.ac.be
authors.forename: J A
authors.initials: JA
authors.lastname: García-Salcedo
authors.forename: P
authors.initials: P
authors.lastname: Gijón
authors.forename: E
authors.initials: E
authors.lastname: Pays
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003513:Cycloheximide / Q000494:pharmacology; D018076:DNA, Complementary / Q000235:genetics; D016054:DNA, Protozoan / Q000235:genetics; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D015321:Gene Rearrangement; D017125:Genes, Protozoan; D006657:Histones / Q000235:genetics*; D006918:Hydroxyurea / Q000494:pharmacology; D008969:Molecular Sequence Data; D019384:Nucleic Acid Synthesis Inhibitors / Q000494:pharmacology; D016366:Open Reading Frames; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016053:RNA, Protozoan / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects; D014346:Trypanosoma brucei brucei / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism
chemical_list: D018076:DNA, Complementary; D016054:DNA, Protozoan; D006657:Histones; D019384:Nucleic Acid Synthesis Inhibitors; D011500:Protein Synthesis Inhibitors; D012333:RNA, Messenger; D016053:RNA, Protozoan; D003513:Cycloheximide; D006918:Hydroxyurea