Heat-shock disruption of trans-splicing in trypanosomes: effect on Hsp70, Hsp85 and tubulin mRNA synthesis**Presented at the Albany Conference on ‘RNA: Catalysis, Splicing, Evolution’, Rensselaerville, NY (U.S.A.), 22–25 September, 1988.

1989 ◽  
pp. 169-175
Author(s):  
Michael L. Muhich ◽  
MiMi P. Hsu ◽  
John C. Boothroyd
Keyword(s):  
Heat Shock ◽  
Rna Catalysis ◽  
Mrna Synthesis ◽  
Trans Splicing ◽  
Tubulin Mrna

Heat-shock disruption of trans-splicing in trypanosomes: effect on Hsp70, Hsp85 and tubulin mRNA synthesis

Gene ◽  
1989 ◽  
Vol 82 (1) ◽  
pp. 169-175 ◽  
Author(s):  
Michael L. Muhich ◽  
MiMi P. Hsu ◽  
John C. Boothroyd
Keyword(s):  
Heat Shock ◽  
Mrna Synthesis ◽  
Trans Splicing ◽  
Tubulin Mrna

Polycistronic transcripts in trypanosomes and their accumulation during heat shock: evidence for a precursor role in mRNA synthesis

1988 ◽  
Vol 8 (9) ◽  
pp. 3837-3846
Author(s):  
M L Muhich ◽  
J C Boothroyd
Keyword(s):  
Heat Shock ◽  
Trypanosoma Brucei ◽  
Mrna Synthesis ◽  
Protein Coding ◽  
Processing Machinery ◽  
Trans Splicing ◽  
Tubulin Mrna ◽  
Polycistronic Transcripts ◽  
Polycistronic Rna

Maturation of mRNA precursors in trypanosomes involves an apparent trans splicing event in which a 39-nucleotide miniexon sequence, common to all trypanosome mRNAs, is joined to the 5' end of a protein-coding exon. We demonstrate that the processing machinery responsible for the maturation of tubulin mRNA precursors in Trypanosoma brucei can be disrupted by heat shock. This results in an accumulation of polycistronic RNA species and a decrease in the abundance of branched splicing intermediates. At normal temperatures, tubulin polycistronic transcripts were also detected and were shown in pulse-chase experiments to be abundantly synthesized and very rapidly turned over. These results, combined with results of the heat shock experiments, suggest that these polycistronic transcripts are the precursors of the (monocistronic) tubulin mRNAs of trypanosomes.

scholarly journals Polycistronic transcripts in trypanosomes and their accumulation during heat shock: evidence for a precursor role in mRNA synthesis.

1988 ◽  
Vol 8 (9) ◽  
pp. 3837-3846 ◽  
Author(s):  
M L Muhich ◽  
J C Boothroyd
Keyword(s):  
Heat Shock ◽  
Trypanosoma Brucei ◽  
Mrna Synthesis ◽  
Protein Coding ◽  
Processing Machinery ◽  
Trans Splicing ◽  
Tubulin Mrna ◽  
Polycistronic Transcripts ◽  
Polycistronic Rna

Maturation of mRNA precursors in trypanosomes involves an apparent trans splicing event in which a 39-nucleotide miniexon sequence, common to all trypanosome mRNAs, is joined to the 5' end of a protein-coding exon. We demonstrate that the processing machinery responsible for the maturation of tubulin mRNA precursors in Trypanosoma brucei can be disrupted by heat shock. This results in an accumulation of polycistronic RNA species and a decrease in the abundance of branched splicing intermediates. At normal temperatures, tubulin polycistronic transcripts were also detected and were shown in pulse-chase experiments to be abundantly synthesized and very rapidly turned over. These results, combined with results of the heat shock experiments, suggest that these polycistronic transcripts are the precursors of the (monocistronic) tubulin mRNAs of trypanosomes.

Increase in protein and tubulin mRNA synthesis in frog sensory neurons treated with the adenylate cyclase activator, forskolin

1990 ◽  
Vol 1 (3,4) ◽  
pp. 225-232
Author(s):  
Richard C. Carlsen ◽  
Marino De Leon ◽  
Wolfram Tetzlaff ◽  
Irma M. Parhad ◽  
Mark A. Bisby
Keyword(s):  
Adenylate Cyclase ◽  
Sensory Neurons ◽  
Mrna Synthesis ◽  
Tubulin Mrna ◽  
Cyclase Activator ◽  
Adenylate Cyclase Activator

scholarly journals Temporal order of RNA-processing reactions in trypanosomes: rapid trans splicing precedes polyadenylation of newly synthesized tubulin transcripts.

1993 ◽  
Vol 13 (1) ◽  
pp. 720-725 ◽  
Author(s):  
E Ullu ◽  
K R Matthews ◽  
C Tschudi
Keyword(s):  
Rna Processing ◽  
Temporal Order ◽  
Kinetic Studies ◽  
Splice Acceptor ◽  
Mrna Synthesis ◽  
Alpha Tubulin ◽  
Spliced Leader ◽  
Polycistronic Transcription ◽  
Trans Splicing

Many trypanosome genes are expressed as part of large polycistronic transcription units. This finding suggests that regulation of mRNA biogenesis may emphasize RNA-processing reactions more so than in other organisms. This study was undertaken to understand the temporal order of two RNA-processing reactions, trans splicing and polyadenylation, in the maturation of trypanosome mRNAs in vivo. Kinetic studies revealed rapid trans splicing of alpha-tubulin, beta-tubulin, and actin pre-mRNAs within 1 to 2 min after synthesis of the 3' splice site. Furthermore, following blockage of pre-mRNA synthesis, newly synthesized spliced leader RNA cannot be used for trans splicing, suggesting that trypanosomes do not accumulate substantial amounts of pre-mRNA which can provide splice acceptor sites. Thus, trans splicing is cotranscriptional. In addition, we show that trans splicing precedes polyadenylation in the processing of trypanosome tubulin pre-mRNAs.

scholarly journals Exonic Sequences in the 5′ Untranslated Region of α-Tubulin mRNA Modulate trans Splicing inTrypanosoma brucei

1998 ◽  
Vol 18 (8) ◽  
pp. 4620-4628 ◽  
Author(s):  
Carlos López-Estraño ◽  
Christian Tschudi ◽  
Elisabetta Ullu
Keyword(s):  
Splice Site ◽  
Competition Assay ◽  
Splice Site Selection ◽  
Tubulin Gene ◽  
Branch Site ◽  
Trans Splicing ◽  
Tubulin Mrna ◽  
Splicing Efficiency ◽  
Β Tubulin

ABSTRACT Previous studies have identified a conserved AG dinucleotide at the 3′ splice site (3′SS) and a polypyrimidine (pPy) tract that are required for trans splicing of polycistronic pre-mRNAs in trypanosomatids. Furthermore, the pPy tract of the Trypanosoma brucei α-tubulin 3′SS region is required to specify accurate 3′-end formation of the upstream β-tubulin gene and transsplicing of the downstream α-tubulin gene. Here, we employed an in vivo cis competition assay to determine whether sequences other than those of the AG dinucleotide and the pPy tract were required for 3′SS identification. Our results indicate that a minimal α-tubulin 3′SS, from the putative branch site region to the AG dinucleotide, is not sufficient for recognition by thetrans-splicing machinery and that polyadenylation is strictly dependent on downstream trans splicing. We show that efficient use of the α-tubulin 3′SS is dependent upon the presence of exon sequences. Furthermore, β-tubulin, but not actin exon sequences or unrelated plasmid sequences, can replace α-tubulin exon sequences for accurate trans-splice-site selection. Taken together, these results support a model in which the informational content required for efficient trans splicing of the α-tubulin pre-mRNA includes exon sequences which are involved in modulation of trans-splicing efficiency. Sequences that positively regulate trans splicing might be similar tocis-splicing enhancers described in other systems.

scholarly journals UbiA, the major polyubiquitin locus in Caenorhabditis elegans, has unusual structural features and is constitutively expressed.

1989 ◽  
Vol 9 (1) ◽  
pp. 268-277 ◽  
Author(s):  
R W Graham ◽  
D Jones ◽  
E P Candido
Keyword(s):  
Amino Acid ◽  
Caenorhabditis Elegans ◽  
Heat Shock ◽  
Tandem Repeats ◽  
Regulatory Element ◽  
Regulatory Elements ◽  
Structural Features ◽  
Putative Promoter Region ◽  
Splice Leader ◽  
Trans Splicing

Ubiquitin is a multifunctional 76-amino-acid protein which plays critical roles in many aspects of cellular metabolism. In Caenorhabditis elegans, the major source of ubiquitin RNA is the polyubiquitin locus, UbiA. UbiA is transcribed as a polycistronic mRNA which contains 11 tandem repeats of ubiquitin sequence and possesses a 2-amino-acid carboxy-terminal extension on the final repeat. The UbiA locus possesses several unusual features not seen in the ubiquitin genes of other organisms studied to date. Mature UbiA mRNA acquires a 22-nucleotide leader sequence via a trans-splicing reaction involving a 100-nucleotide splice leader RNA derived from a different chromosome. UbiA is also unique among known polyubiquitin genes in containing four cis-spliced introns within its coding sequence. Thus, UbiA is one of a small class of genes found in higher eucaryotes whose heterogeneous nuclear RNA undergoes both cis and trans splicing. The putative promoter region of UbiA contains a number of potential regulatory elements: (i) a cytosine-rich block, (ii) two sequences resembling the heat shock regulatory element, and (iii) a palindromic sequence with homology to the DNA-binding site of the mammalian steroid hormone receptor. The expression of the UbiA gene has been studied under various heat shock conditions and has been monitored during larval moulting and throughout the major stages of development. These studies indicate that the expression of the UbiA gene is not inducible by acute or chronic heat shock and does not appear to be under nutritional or developmental regulation in C. elegans.

UbiA, the major polyubiquitin locus in Caenorhabditis elegans, has unusual structural features and is constitutively expressed

1989 ◽  
Vol 9 (1) ◽  
pp. 268-277
Author(s):  
R W Graham ◽  
D Jones ◽  
E P Candido
Keyword(s):  
Amino Acid ◽  
Caenorhabditis Elegans ◽  
Heat Shock ◽  
Tandem Repeats ◽  
Regulatory Element ◽  
Regulatory Elements ◽  
Structural Features ◽  
Putative Promoter Region ◽  
Splice Leader ◽  
Trans Splicing

Ubiquitin is a multifunctional 76-amino-acid protein which plays critical roles in many aspects of cellular metabolism. In Caenorhabditis elegans, the major source of ubiquitin RNA is the polyubiquitin locus, UbiA. UbiA is transcribed as a polycistronic mRNA which contains 11 tandem repeats of ubiquitin sequence and possesses a 2-amino-acid carboxy-terminal extension on the final repeat. The UbiA locus possesses several unusual features not seen in the ubiquitin genes of other organisms studied to date. Mature UbiA mRNA acquires a 22-nucleotide leader sequence via a trans-splicing reaction involving a 100-nucleotide splice leader RNA derived from a different chromosome. UbiA is also unique among known polyubiquitin genes in containing four cis-spliced introns within its coding sequence. Thus, UbiA is one of a small class of genes found in higher eucaryotes whose heterogeneous nuclear RNA undergoes both cis and trans splicing. The putative promoter region of UbiA contains a number of potential regulatory elements: (i) a cytosine-rich block, (ii) two sequences resembling the heat shock regulatory element, and (iii) a palindromic sequence with homology to the DNA-binding site of the mammalian steroid hormone receptor. The expression of the UbiA gene has been studied under various heat shock conditions and has been monitored during larval moulting and throughout the major stages of development. These studies indicate that the expression of the UbiA gene is not inducible by acute or chronic heat shock and does not appear to be under nutritional or developmental regulation in C. elegans.

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