title: Heat-shock disruption of trans-splicing in trypanosomes: effect on Hsp70, Hsp85 and tubulin mRNA synthesis.
abstract: The synthesis of most, if not all, mRNA in trypanosomes involves the splicing in trans of two RNA molecules. One of these includes the common 5' mini-exon or spliced-leader sequence, while the other contains the complete protein-coding exon sequence for a given gene. We have recently shown that trans-splicing of tubulin transcripts is disrupted by heat shock, whereas trans-splicing of Hsp70 mRNA continues unabated, despite the increased expression of this latter gene [Muhich and Boothroyd, Mol. Cell Biol. 8 (1988) 3837-3846]. In this report we show that, in addition to being polyadenylated, the dimeric beta-alpha tubulin transcripts which accumulate as a result of heat shock have a correctly processed 5'-end (through mini-exon addition), and that the extent of disruption is proportional to the degree of heat shock. We further show that mRNA levels for two evolutionarily-conserved heat-shock proteins, Hsp70 and Hsp85, are increased under the splicing-disruptive conditions of heat shock.
authors.affiliation: Department of Microbiology and Immunology, Stanford University School of Medicine, CA 94305-5402.
authors.forename: M L
authors.initials: ML
authors.lastname: Muhich
authors.forename: M P
authors.initials: MP
authors.lastname: Hsu
authors.forename: J C
authors.initials: JC
authors.lastname: Boothroyd
mesh_terms: D000818:Animals; D001483:Base Sequence; D005091:Exons; D005786:Gene Expression Regulation; D006360:Heat-Shock Proteins / Q000096:biosynthesis / Q000235:genetics*; D006358:Hot Temperature; D008969:Molecular Sequence Data; D012326:RNA Splicing; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism; D012689:Sequence Homology, Nucleic Acid; D014346:Trypanosoma brucei brucei / Q000235:genetics* / Q000378:metabolism; D014349:Trypanosoma cruzi / Q000235:genetics; D014404:Tubulin / Q000096:biosynthesis / Q000235:genetics*
chemical_list: D006360:Heat-Shock Proteins; D012333:RNA, Messenger; D014404:Tubulin