BARBARA LEE - Academia.edu (original) (raw)
Related Authors
Teagasc, Irish Agriculture and Food Development Authority
Uploads
Papers by BARBARA LEE
Nucleic Acids Research, 1996
Transcription from a minimal HIV-1 promoter containing the three Sp1 binding sites and TATA box c... more Transcription from a minimal HIV-1 promoter containing the three Sp1 binding sites and TATA box can be activated without Tat by template DNA replication. Here we show that this activation can also be mediated by recombinant GAL4 fusion proteins containing the activation domains of Sp1, VP16 or CTF (or by full-length GAL4) targeted to the HIV-1 promoter by replacing the Sp1 sites with five GAL4 binding sites. Thus Sp1 is not unique in its ability to mediate replication activated transcription, although the degree of processivity elicited by the different activators varied significantly from strongly processive (GAL4-VP16) to relatively non-processive (GAL4-Sp1 or-CTF). Processive GAL4-VP16-activated transcription, but not efficient initiation, required multiple GAL4 binding sites. In the presence of Tat, transcription with GAL4-SP1 and GAL4-CTF was further activated (principally at the level of processivity) but GAL4-VP16-potentiated transcription was only slightly stimulated. The Tat-dependent switch from non-processive to fully processive transcription was particularly marked for GAL4-Sp1, an effect which may be relevant to the selection of Sp1 binding sites by the HIV-1 promoter.
Science, 1998
The direct association between messenger RNA (mRNA) 3′-end processing and the termination of tran... more The direct association between messenger RNA (mRNA) 3′-end processing and the termination of transcription was established for the CYC1 gene of Saccharomyces cerevisiae . The mutation of factors involved in the initial cleavage of the primary transcript at the poly(A) site ( RNA14 , RNA15 , and PCF11 ) disrupted transcription termination at the 3′ end of the CYC1 gene. In contrast, the mutation of factors involved in the subsequent polyadenylation step ( PAP1 , FIP1 , and YTH1 ) had little effect. Thus, cleavage factors link transcription termination of RNA polymerase II with pre-mRNA 3′-end processing.
Proceedings of the National Academy of Sciences, 2001
Genes & Development, 2002
Reconstruction of a gene with its introns removed results in reduced levels of cytoplasmic mRNA. ... more Reconstruction of a gene with its introns removed results in reduced levels of cytoplasmic mRNA. This is partly explained by introns promoting the export of mRNA through coupling splicing to nuclear export processes. However, we show here that splicing signals can have a direct role in enhancing gene transcription. Removal of promoter proximal splice signals from a mammalian gene or the excision of introns from two different yeast genes results in a marked reduction in levels of nascent transcription, based on both nuclear run-on and direct image analysis. This further establishes that mRNA processing and transcription are tightly coupled mechanisms.
Proceedings of the …, 2001
The carboxyl-terminal domain (CTD) of the largest subunit of RNA polymerase II plays an important... more The carboxyl-terminal domain (CTD) of the largest subunit of RNA polymerase II plays an important role in transcription and processing of the nascent transcript by interacting with both transcription and RNA processing factors. We show here that the cleavage/polyadenylation factor IA of ...
Science, 1998
The direct association between messenger RNA (mRNA) 3′-end processing and the termination of tran... more The direct association between messenger RNA (mRNA) 3′-end processing and the termination of transcription was established for the CYC1 gene of Saccharomyces cerevisiae . The mutation of factors involved in the initial cleavage of the primary transcript at the poly(A) site ( RNA14 , RNA15 , and PCF11 ) disrupted transcription termination at the 3′ end of the CYC1 gene. In contrast, the mutation of factors involved in the subsequent polyadenylation step ( PAP1 , FIP1 , and YTH1 ) had little effect. Thus, cleavage factors link transcription termination of RNA polymerase II with pre-mRNA 3′-end processing.
The EMBO journal, 1997
Transcription 'run-on' (TRO) analysis using permeabilized yeast cells indicates that tr... more Transcription 'run-on' (TRO) analysis using permeabilized yeast cells indicates that transcription terminates between 180 and 380 bp downstream of the poly(A) site of the Schizosaccharomyces pombe ura4 gene. Two signals direct RNA polymerase II (pol II) to stop transcription: the ...
Nucleic Acids Research, 1996
Transcription from a minimal HIV-1 promoter containing the three Sp1 binding sites and TATA box c... more Transcription from a minimal HIV-1 promoter containing the three Sp1 binding sites and TATA box can be activated without Tat by template DNA replication. Here we show that this activation can also be mediated by recombinant GAL4 fusion proteins containing the activation domains of Sp1, VP16 or CTF (or by full-length GAL4) targeted to the HIV-1 promoter by replacing the Sp1 sites with five GAL4 binding sites. Thus Sp1 is not unique in its ability to mediate replication activated transcription, although the degree of processivity elicited by the different activators varied significantly from strongly processive (GAL4-VP16) to relatively non-processive (GAL4-Sp1 or-CTF). Processive GAL4-VP16-activated transcription, but not efficient initiation, required multiple GAL4 binding sites. In the presence of Tat, transcription with GAL4-SP1 and GAL4-CTF was further activated (principally at the level of processivity) but GAL4-VP16-potentiated transcription was only slightly stimulated. The Tat-dependent switch from non-processive to fully processive transcription was particularly marked for GAL4-Sp1, an effect which may be relevant to the selection of Sp1 binding sites by the HIV-1 promoter.
Science, 1998
The direct association between messenger RNA (mRNA) 3′-end processing and the termination of tran... more The direct association between messenger RNA (mRNA) 3′-end processing and the termination of transcription was established for the CYC1 gene of Saccharomyces cerevisiae . The mutation of factors involved in the initial cleavage of the primary transcript at the poly(A) site ( RNA14 , RNA15 , and PCF11 ) disrupted transcription termination at the 3′ end of the CYC1 gene. In contrast, the mutation of factors involved in the subsequent polyadenylation step ( PAP1 , FIP1 , and YTH1 ) had little effect. Thus, cleavage factors link transcription termination of RNA polymerase II with pre-mRNA 3′-end processing.
Proceedings of the National Academy of Sciences, 2001
Genes & Development, 2002
Reconstruction of a gene with its introns removed results in reduced levels of cytoplasmic mRNA. ... more Reconstruction of a gene with its introns removed results in reduced levels of cytoplasmic mRNA. This is partly explained by introns promoting the export of mRNA through coupling splicing to nuclear export processes. However, we show here that splicing signals can have a direct role in enhancing gene transcription. Removal of promoter proximal splice signals from a mammalian gene or the excision of introns from two different yeast genes results in a marked reduction in levels of nascent transcription, based on both nuclear run-on and direct image analysis. This further establishes that mRNA processing and transcription are tightly coupled mechanisms.
Proceedings of the …, 2001
The carboxyl-terminal domain (CTD) of the largest subunit of RNA polymerase II plays an important... more The carboxyl-terminal domain (CTD) of the largest subunit of RNA polymerase II plays an important role in transcription and processing of the nascent transcript by interacting with both transcription and RNA processing factors. We show here that the cleavage/polyadenylation factor IA of ...
Science, 1998
The direct association between messenger RNA (mRNA) 3′-end processing and the termination of tran... more The direct association between messenger RNA (mRNA) 3′-end processing and the termination of transcription was established for the CYC1 gene of Saccharomyces cerevisiae . The mutation of factors involved in the initial cleavage of the primary transcript at the poly(A) site ( RNA14 , RNA15 , and PCF11 ) disrupted transcription termination at the 3′ end of the CYC1 gene. In contrast, the mutation of factors involved in the subsequent polyadenylation step ( PAP1 , FIP1 , and YTH1 ) had little effect. Thus, cleavage factors link transcription termination of RNA polymerase II with pre-mRNA 3′-end processing.
The EMBO journal, 1997
Transcription 'run-on' (TRO) analysis using permeabilized yeast cells indicates that tr... more Transcription 'run-on' (TRO) analysis using permeabilized yeast cells indicates that transcription terminates between 180 and 380 bp downstream of the poly(A) site of the Schizosaccharomyces pombe ura4 gene. Two signals direct RNA polymerase II (pol II) to stop transcription: the ...