Different sequence elements are required for function of the cauliflower mosaic virus polyadenylation site in Saccharomyces cerevisiae compared with in plants

1992 ◽  
Vol 12 (5) ◽  
pp. 2322-2330
Author(s):  
S Irniger ◽  
H Sanfaçon ◽  
C M Egli ◽  
G H Braus

We show that the polyadenylation site derived from the plant cauliflower mosaic virus (CaMV) is specifically functional in the yeast Saccharomyces cerevisiae. The mRNA 3' endpoints were mapped at the same position in yeast cells as in plants, and the CaMV polyadenylation site was recognized in an orientation-dependent manner. Mutational analysis of the CaMV 3'-end-formation signal revealed that multiple elements are essential for proper activity in yeast cells, including two upstream elements that are situated more than 100 and 43 to 51 nucleotides upstream of the poly(A) addition site and the sequences at or near the poly(A) addition site. A comparison of the sequence elements that are essential for proper function of the CaMV signal in yeast cells and plants showed that both organisms require a distal and a proximal upstream element but that these sequence elements are not identical in yeast cells and plants. The key element for functioning of the CaMV signal in yeast cells is the sequence TAGTATGTA, which is similar to a sequence previously proposed to act in yeast cells as a bipartite signal, namely, TAG ... TATGTA. Deletion of this sequence in the CaMV polyadenylation signal abolished 3'-end formation in yeast cells, and a single point mutation in this motif reduced the activity of the CaMV signal to below 15%. These results indicate that the bipartite sequence element acts as a signal for 3'-end formation in yeast cells but only together with other cis-acting elements.

1992 ◽  
Vol 12 (5) ◽  
pp. 2322-2330 ◽  
Author(s):  
S Irniger ◽  
H Sanfaçon ◽  
C M Egli ◽  
G H Braus

We show that the polyadenylation site derived from the plant cauliflower mosaic virus (CaMV) is specifically functional in the yeast Saccharomyces cerevisiae. The mRNA 3' endpoints were mapped at the same position in yeast cells as in plants, and the CaMV polyadenylation site was recognized in an orientation-dependent manner. Mutational analysis of the CaMV 3'-end-formation signal revealed that multiple elements are essential for proper activity in yeast cells, including two upstream elements that are situated more than 100 and 43 to 51 nucleotides upstream of the poly(A) addition site and the sequences at or near the poly(A) addition site. A comparison of the sequence elements that are essential for proper function of the CaMV signal in yeast cells and plants showed that both organisms require a distal and a proximal upstream element but that these sequence elements are not identical in yeast cells and plants. The key element for functioning of the CaMV signal in yeast cells is the sequence TAGTATGTA, which is similar to a sequence previously proposed to act in yeast cells as a bipartite signal, namely, TAG ... TATGTA. Deletion of this sequence in the CaMV polyadenylation signal abolished 3'-end formation in yeast cells, and a single point mutation in this motif reduced the activity of the CaMV signal to below 15%. These results indicate that the bipartite sequence element acts as a signal for 3'-end formation in yeast cells but only together with other cis-acting elements.


1986 ◽  
Vol 6 (1) ◽  
pp. 241-245
Author(s):  
C Mann ◽  
R W Davis

The CEN4 sequences from chromosome 4 that impart mitotic stability to autonomously replicating (ARS) plasmids in yeast cells have been localized to a 1,755-base-pair (bp) fragment. This fragment could be cut in half to give two adjacent, nonoverlapping fragments, that each contained some mitotic stabilization sequences. One of the half-fragments worked as efficiently as the larger fragment from which it was derived, while the other half provided a much poorer degree of mitotic stabilization. Sequencing of 2,095 bp of DNA including this region revealed the presence of a centromere consensus sequence, elements I, II, and III (M. Fitzgerald-Hayes, L. Clarke, and J. Carbon, Cell 29:235-244, 1982), in the half-fragment providing high levels of mitotic stability. The poorly stabilizing half-fragment did not contain any obvious sequence homologies to other centromere sequences. Deletion analysis of the 1,755-bp fragment indicated that removal of the 14-bp element I plus 16 of the 82 bp of element II impaired mitotic stability. Removal of elements I and II eliminated the mitotic stability provided by the consensus sequence.


1987 ◽  
Vol 7 (12) ◽  
pp. 4522-4534 ◽  
Author(s):  
R Ng ◽  
J Carbon

Centromeres on chromosomes in the yeast Saccharomyces cerevisiae contain approximately 140 base pairs (bp) of DNA. The functional centromere (CEN) region contains three important sequence elements (I, PuTCACPuTG; II, 78 to 86 bp of high-AT DNA; and III, a conserved 25-bp sequence with internal bilateral symmetry). Various point mutations or deletions in the element III region have a profound effect on CEN function in vivo, indicating that this DNA region is a key protein-binding site. This has been confirmed by the use of two in vitro assays to detect binding of yeast proteins to DNA fragments containing wild-type or mutationally altered CEN3 sequences. An exonuclease III protection assay was used to demonstrate specific binding of proteins to the element III region of CEN3. In addition, a gel DNA fragment mobility shift assay was used to characterize the binding reaction parameters. Sequence element III mutations that inactivate CEN function in vivo also prevent binding of proteins in the in vitro assays. The mobility shift assay indicates that double-stranded DNAs containing sequence element III efficiently bind proteins in the absence of sequence elements I and II, although the latter sequences are essential for optimal CEN function in vivo.


1991 ◽  
Vol 11 (6) ◽  
pp. 3060-3069 ◽  
Author(s):  
S Irniger ◽  
C M Egli ◽  
G H Braus

This report provides an analysis of the function of polyadenylation sites from six different genes of the yeast Saccharomyces cerevisiae. These sites were tested for their ability to turn off read-through transcription into the URA3 gene in vivo when inserted into an ACT-URA3 fusion gene. The 3' ends of all polyadenylation sites inserted into the test system in their natural configuration are identical to the 3' ends of the chromosomal genes. We identified two classes of polyadenylation sites: (i) efficient sites (originating from the genes GCN4 and PHO5) that were functional in a strict orientation-dependent manner and (ii) bidirectional sites (derived from ARO4, TRP1, and TRP4) that had a distinctly reduced efficiency. The ADH1 polyadenylation site was efficient and bidirectional and was shown to be a combination of two polyadenylation sites of two convergently transcribed genes. Sequence comparison revealed that all efficient unidirectional polyadenylation sites contain the sequence TTTTTAT, whereas all bidirectional sites have the tripartite sequence TAG...TA (T)GT...TTT. Both sequence elements have previously been proposed to be involved in 3' end formation. Site-directed point mutagenesis of the TTTTTAT sequence had no effect, whereas mutations within the tripartite sequence caused a reduced efficiency for 3' end formation. The tripartite sequence alone, however, is not sufficient for 3' end formation, but it might be part of a signal sequence in the bidirectional class of yeast polyadenylation sites. Our findings support the assumption that there are at least two different mechanisms with different sequence elements directing 3' end formation in yeast.


1991 ◽  
Vol 142 (4) ◽  
pp. 297-302 ◽  
Author(s):  
D. Kirchherr ◽  
T. Wurch ◽  
J.-M. Mesnard ◽  
G. Lebeurier

1987 ◽  
Vol 7 (12) ◽  
pp. 4522-4534
Author(s):  
R Ng ◽  
J Carbon

Centromeres on chromosomes in the yeast Saccharomyces cerevisiae contain approximately 140 base pairs (bp) of DNA. The functional centromere (CEN) region contains three important sequence elements (I, PuTCACPuTG; II, 78 to 86 bp of high-AT DNA; and III, a conserved 25-bp sequence with internal bilateral symmetry). Various point mutations or deletions in the element III region have a profound effect on CEN function in vivo, indicating that this DNA region is a key protein-binding site. This has been confirmed by the use of two in vitro assays to detect binding of yeast proteins to DNA fragments containing wild-type or mutationally altered CEN3 sequences. An exonuclease III protection assay was used to demonstrate specific binding of proteins to the element III region of CEN3. In addition, a gel DNA fragment mobility shift assay was used to characterize the binding reaction parameters. Sequence element III mutations that inactivate CEN function in vivo also prevent binding of proteins in the in vitro assays. The mobility shift assay indicates that double-stranded DNAs containing sequence element III efficiently bind proteins in the absence of sequence elements I and II, although the latter sequences are essential for optimal CEN function in vivo.


1991 ◽  
Vol 11 (6) ◽  
pp. 3060-3069
Author(s):  
S Irniger ◽  
C M Egli ◽  
G H Braus

This report provides an analysis of the function of polyadenylation sites from six different genes of the yeast Saccharomyces cerevisiae. These sites were tested for their ability to turn off read-through transcription into the URA3 gene in vivo when inserted into an ACT-URA3 fusion gene. The 3' ends of all polyadenylation sites inserted into the test system in their natural configuration are identical to the 3' ends of the chromosomal genes. We identified two classes of polyadenylation sites: (i) efficient sites (originating from the genes GCN4 and PHO5) that were functional in a strict orientation-dependent manner and (ii) bidirectional sites (derived from ARO4, TRP1, and TRP4) that had a distinctly reduced efficiency. The ADH1 polyadenylation site was efficient and bidirectional and was shown to be a combination of two polyadenylation sites of two convergently transcribed genes. Sequence comparison revealed that all efficient unidirectional polyadenylation sites contain the sequence TTTTTAT, whereas all bidirectional sites have the tripartite sequence TAG...TA (T)GT...TTT. Both sequence elements have previously been proposed to be involved in 3' end formation. Site-directed point mutagenesis of the TTTTTAT sequence had no effect, whereas mutations within the tripartite sequence caused a reduced efficiency for 3' end formation. The tripartite sequence alone, however, is not sufficient for 3' end formation, but it might be part of a signal sequence in the bidirectional class of yeast polyadenylation sites. Our findings support the assumption that there are at least two different mechanisms with different sequence elements directing 3' end formation in yeast.


1986 ◽  
Vol 6 (1) ◽  
pp. 241-245 ◽  
Author(s):  
C Mann ◽  
R W Davis

The CEN4 sequences from chromosome 4 that impart mitotic stability to autonomously replicating (ARS) plasmids in yeast cells have been localized to a 1,755-base-pair (bp) fragment. This fragment could be cut in half to give two adjacent, nonoverlapping fragments, that each contained some mitotic stabilization sequences. One of the half-fragments worked as efficiently as the larger fragment from which it was derived, while the other half provided a much poorer degree of mitotic stabilization. Sequencing of 2,095 bp of DNA including this region revealed the presence of a centromere consensus sequence, elements I, II, and III (M. Fitzgerald-Hayes, L. Clarke, and J. Carbon, Cell 29:235-244, 1982), in the half-fragment providing high levels of mitotic stability. The poorly stabilizing half-fragment did not contain any obvious sequence homologies to other centromere sequences. Deletion analysis of the 1,755-bp fragment indicated that removal of the 14-bp element I plus 16 of the 82 bp of element II impaired mitotic stability. Removal of elements I and II eliminated the mitotic stability provided by the consensus sequence.


2004 ◽  
Vol 24 (10) ◽  
pp. 4267-4274 ◽  
Author(s):  
Lajos Haracska ◽  
Carlos A. Torres-Ramos ◽  
Robert E. Johnson ◽  
Satya Prakash ◽  
Louise Prakash

ABSTRACT The Rad6-Rad18 ubiquitin-conjugating enzyme complex of Saccharomyces cerevisiae promotes replication through DNA lesions via three separate pathways that include translesion synthesis (TLS) by DNA polymerases ζ (Polζ) and Polη and postreplicational repair mediated by the Mms2-Ubc13 ubiquitin-conjugating enzyme and Rad5. Here we report our studies with a proliferating cell nuclear antigen (PCNA) mutation, pol30-119, which results from a change of the lysine 164 residue to arginine. It has been shown recently that following treatment of yeast cells with DNA-damaging agents, the lysine 164 residue of PCNA becomes monoubiquitinated in a Rad6-Rad18-dependent manner and that subsequently this PCNA residue is polyubiquitinated via a lysine 63-linked ubiquitin chain in an Mms2-Ubc13-, Rad5-dependent manner. PCNA is also modified by SUMO conjugation at the lysine 164 residue. Our genetic studies with the pol30-119 mutation show that in addition to conferring a defect in Polζ-dependent UV mutagenesis and in Polη-dependent TLS, this PCNA mutation inhibits postreplicational repair of discontinuities that form in the newly synthesized strand across from UV lesions. In addition, we provide evidence for the activation of the RAD52 recombinational pathway in the pol30-119 mutant and we infer that SUMO conjugation at the lysine 164 residue of PCNA has a role in suppressing the Rad52-dependent postreplicational repair pathway.


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