Survey of four different photoreactive moieties for DNA photoaffinity labeling of yeast RNA polymerase III transcription complexes

Ample evidence indicates that Alu family interspersed elements retrotranspose via primary transcripts synthesized by RNA polymerase III (pol III) and that this transposition sometimes results in genetic disorders in humans. However, Alu primary transcripts can be processed posttranscriptionally, diverting them away from the transposition pathway. The pol III termination signal of a well-characterized murine B1 (Alu-equivalent) element inhibits RNA 3' processing, thereby stabilizing the putative transposition intermediary. We used an immobilized template-based assay to examine transcription termination by VA1, 7SL, and Alu class III templates and the role of transcript release in the pol III terminator-dependent inhibition of processing of B1-Alu transcripts. We found that the RNA-binding protein La confers this terminator-dependent 3' processing inhibition on transcripts released from the B1-Alu template. Using pure recombinant La protein and affinity-purified transcription complexes, we also demonstrate that La facilitates multiple rounds of transcription reinitiation by pol III. These results illustrate an important role for La in RNA production by demonstrating its ability to clear the termination sites of class III templates, thereby promoting efficient use of transcription complexes by pol III. The role of La as a potential regulatory factor in transcript maturation and how this might apply to Alu interspersed elements is discussed.

Download Full-text

Silk gland-specific tRNA(Ala) genes interact more weakly than constitutive tRNA(Ala) genes with silkworm TFIIIB and polymerase III fractions.

Molecular and Cellular Biology ◽

10.1128/mcb.14.3.1806 ◽

1994 ◽

Vol 14 (3) ◽

pp. 1806-1814 ◽

Cited By ~ 11

Author(s):

H S Sullivan ◽

L S Young ◽

C N White ◽

K U Sprague

Keyword(s):

Rna Polymerase ◽

Rna Polymerase Iii ◽

Silk Gland ◽

Flanking Sequence ◽

Transcription Machinery ◽

Polymerase Iii ◽

Active Transcription ◽

The Difference ◽

Transcription Complexes

Constitutive and silk gland-specific tRNA(Ala) genes from silkworms have very different transcriptional properties in vitro. Typically, the constitutive type, which encodes tRNA(AlaC), directs transcription much more efficiently than does the silk gland-specific type, which encodes tRNA(AlaSG). We think that the inefficiency of the tRNA(AlaCG) gene underlies its capacity to be turned off in non-silk gland cells. An economical model is that the tRNA(AlaSG) promoter interacts poorly, relative to the tRNA(AlaC) promoter, with one or more components of the basal transcription machinery. As a consequence, the tRNA(AlaSG) gene directs the formation of fewer transcription complexes or of complexes with reduced cycling ability. Here we show that the difference in the number of active transcription complexes accounts for the difference in tRNA(AlaC) and tRNA(AlaSG) transcription rates. To determine whether a particular component of the silkworm transcription machinery is responsible for reduced complex formation on the tRNA(AlaSG) gene, we measured competition by templates for defined fractions of this machinery. We find that the tRNA(AlaSG) gene is greatly impaired, in comparison with the tRNA(AlaC) gene, in competition for either TFIIIB or RNA polymerase III. Competition for each of these fractions is also strongly influenced by the nature of the 5' flanking sequence, the promoter element responsible for the distinctive transcriptional properties of tRNA(AlaSG) and tRNA(AlaC) genes. These results suggest that differential interaction with TFIIIB or RNA polymerase III is a critical functional distinction between these genes.

Download Full-text

Genomic binding profiles of functionally distinct RNA polymerase III transcription complexes in human cells

Nature Structural & Molecular Biology ◽

10.1038/nsmb.1794 ◽

2010 ◽

Vol 17 (5) ◽

pp. 635-640 ◽

Cited By ~ 139

Author(s):

Zarmik Moqtaderi ◽

Jie Wang ◽

Debasish Raha ◽

Robert J White ◽

Michael Snyder ◽

...

Keyword(s):

Rna Polymerase ◽

Rna Polymerase Iii ◽

Human Cells ◽

Polymerase Iii ◽

Transcription Complexes

Download Full-text

Phosphorylation of the Human La Antigen on Serine 366 Can Regulate Recycling of RNA Polymerase III Transcription Complexes

Cell ◽

10.1016/s0092-8674(00)81913-3 ◽

1997 ◽

Vol 88 (5) ◽

pp. 707-715 ◽

Cited By ~ 75

Author(s):

Hao Fan ◽

Amy L Sakulich ◽

John L Goodier ◽

Xiaolong Zhang ◽

Jun Qin ◽

...

Keyword(s):

Rna Polymerase ◽

Rna Polymerase Iii ◽

Polymerase Iii ◽

La Antigen ◽

Transcription Complexes

Download Full-text

Eukaryotic transcription termination factor La mediates transcript release and facilitates reinitiation by RNA polymerase III.

Molecular and Cellular Biology ◽

10.1128/mcb.14.3.2147 ◽

1994 ◽

Vol 14 (3) ◽

pp. 2147-2158 ◽

Cited By ~ 97

Author(s):

R J Maraia ◽

D J Kenan ◽

J D Keene

Keyword(s):

Rna Polymerase ◽

Rna Binding ◽

Transcription Termination ◽

Rna Polymerase Iii ◽

Class Iii ◽

Ample Evidence ◽

Polymerase Iii ◽

Transcription Complexes ◽

Pol Iii

Ample evidence indicates that Alu family interspersed elements retrotranspose via primary transcripts synthesized by RNA polymerase III (pol III) and that this transposition sometimes results in genetic disorders in humans. However, Alu primary transcripts can be processed posttranscriptionally, diverting them away from the transposition pathway. The pol III termination signal of a well-characterized murine B1 (Alu-equivalent) element inhibits RNA 3' processing, thereby stabilizing the putative transposition intermediary. We used an immobilized template-based assay to examine transcription termination by VA1, 7SL, and Alu class III templates and the role of transcript release in the pol III terminator-dependent inhibition of processing of B1-Alu transcripts. We found that the RNA-binding protein La confers this terminator-dependent 3' processing inhibition on transcripts released from the B1-Alu template. Using pure recombinant La protein and affinity-purified transcription complexes, we also demonstrate that La facilitates multiple rounds of transcription reinitiation by pol III. These results illustrate an important role for La in RNA production by demonstrating its ability to clear the termination sites of class III templates, thereby promoting efficient use of transcription complexes by pol III. The role of La as a potential regulatory factor in transcript maturation and how this might apply to Alu interspersed elements is discussed.

Download Full-text

Formation of open and elongating transcription complexes by RNA polymerase III

Journal of Molecular Biology ◽

10.1016/0022-2836(92)90123-2 ◽

1992 ◽

Vol 226 (1) ◽

pp. 47-58 ◽

Cited By ~ 45

Author(s):

George A. Kassavetis ◽

Jaime A. Blanco ◽

Terence E. Johnson ◽

E.Peter Geiduschek

Keyword(s):

Rna Polymerase ◽

Rna Polymerase Iii ◽

Polymerase Iii ◽

Transcription Complexes

Download Full-text

Silk gland-specific tRNA(Ala) genes interact more weakly than constitutive tRNA(Ala) genes with silkworm TFIIIB and polymerase III fractions

Molecular and Cellular Biology ◽

10.1128/mcb.14.3.1806-1814.1994 ◽

1994 ◽

Vol 14 (3) ◽

pp. 1806-1814

Author(s):

H S Sullivan ◽

L S Young ◽

C N White ◽

K U Sprague

Keyword(s):

Rna Polymerase ◽

Rna Polymerase Iii ◽

Silk Gland ◽

Flanking Sequence ◽

Transcription Machinery ◽

Polymerase Iii ◽

Active Transcription ◽

The Difference ◽

Transcription Complexes

Constitutive and silk gland-specific tRNA(Ala) genes from silkworms have very different transcriptional properties in vitro. Typically, the constitutive type, which encodes tRNA(AlaC), directs transcription much more efficiently than does the silk gland-specific type, which encodes tRNA(AlaSG). We think that the inefficiency of the tRNA(AlaCG) gene underlies its capacity to be turned off in non-silk gland cells. An economical model is that the tRNA(AlaSG) promoter interacts poorly, relative to the tRNA(AlaC) promoter, with one or more components of the basal transcription machinery. As a consequence, the tRNA(AlaSG) gene directs the formation of fewer transcription complexes or of complexes with reduced cycling ability. Here we show that the difference in the number of active transcription complexes accounts for the difference in tRNA(AlaC) and tRNA(AlaSG) transcription rates. To determine whether a particular component of the silkworm transcription machinery is responsible for reduced complex formation on the tRNA(AlaSG) gene, we measured competition by templates for defined fractions of this machinery. We find that the tRNA(AlaSG) gene is greatly impaired, in comparison with the tRNA(AlaC) gene, in competition for either TFIIIB or RNA polymerase III. Competition for each of these fractions is also strongly influenced by the nature of the 5' flanking sequence, the promoter element responsible for the distinctive transcriptional properties of tRNA(AlaSG) and tRNA(AlaC) genes. These results suggest that differential interaction with TFIIIB or RNA polymerase III is a critical functional distinction between these genes.

Download Full-text