Expression of Ty-<i>lacZ</i>fusions in<i>Saccharomyces cerevisiae</i>

Bowen, Ben; Fulton, Alexandra M.; Tuite, Mick F.; Kingsman, Susan M.; Kingsman, Alan J.

doi:10.1093/nar/12.3.1627

Cited by 18 publications

(13 citation statements)

References 38 publications

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“…The upstream portion of the 8 5' end (pK-6, pK-16, and pK-17) or an RNA band broader on an optimal exposure than expected for a single initiation site (pK-13, pK-37, and pK-38). (B) Hybridization analysis.…”

Section: Resultsmentioning

confidence: 99%

A region internal to the coding sequences is essential for transcription of the yeast Ty-D15 element.

Yu¹,

Elder²

1989

Mol. Cell. Biol.

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The major transcript of the yeast transposable element Tyl has its 5' end in one 8 and the 3' end in the opposite 8, the direct repeats of about 335 base pairs (bp) at each end of the element. The transcriptional initiation signals of the Ty-D15 element that give rise to this transcript were found to have a number of unusual characteristics. The 5' 8 by itself, which contained the initiation site for Ty transcription, gave no (27,35,49). The Tyl and Ty2 class of elements both have Bs, direct repeats of about 335 base pairs (bp), flanking the 5.2-kbp E region of the element (Fig. 1). Two regions in the E totaling 3 kbp that differ significantly in DNA sequence distinguish the Tyl and Ty2 classes. The similarity of Ty elements to vertebrate retroviruses at both the DNA and RNA levels first suggested a close relationship between these elements. The recent demonstrations that Ty transposes through an RNA intermediate (4), encodes retroviruslike proteins such as reverse transcriptase (7,19,28), and forms viruslike particles in the yeast cell (19, 28) have confirmed the relationship of these retrotransposons.In addition to their transposition mechanisms, Ty elements are also noteworthy for their transcriptional properties with regard to the elements themselves and their effects on expression of adjacent genes. Ty elements are highly transcribed to produce 5 to 10% of the poly ( enon (14,40,51). The Ty sequences essential for this increased expression are in the E downstream of the 5' 8 (15, 33, 36). DNA sequence analysis has shown that this internal activating region (IAR) contains sequences similar to those of the simian virus 40 enhancer that functions in cells of higher eucaryotes (15,36). However, recent work indicates that a region of the £ not containing similarities to the simian virus 40 enhancer may in fact activate the flanking gene (33). Several putative binding sites for the MATa2-MATal repressor are also present in the E and may be responsible for the mating-type regulation of genes activated by an inserted Ty element (15,16). These studies, then, indicate that sequences necessary for the ROAM effect are in the translated region of the Ty element.It seems possible that these sequences in the E may also play a role in transcription of the Ty element itself, especially since flanking genes and Ty elements both respond to mating-type signals (13,46). Liao et al. (24) and Fulton et al. (18) have in fact presented evidence that regions in the E as well as 8 sequences upstream of the initiation site are necessary for transcription of Ty elements. In this study, the transcriptional properties of a particular Tyl element, Ty-D15, were examined to determine the location of the required sequences. Transcription of this Ty element is shown to depend on an IAR. Another surprising observation is that transcription still occurs when the portion of the 8 upstream of the initiation site is replaced with other DNA fragments.MATERIALS AND METHODS Strains. Yeast strain YL7 (YNN211 [40], MATa ura3-52 his3A200) was use...

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Section: Resultsmentioning

confidence: 99%

A region internal to the coding sequences is essential for transcription of the yeast Ty-D15 element.

Yu¹,

Elder²

1989

Mol. Cell. Biol.

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“…The maps are drawn such that 5S gene transcription is from right to left and the presumptive Ty transcript of pYeE147 is synthesised from left to right. This is to facilitate comparison with published maps of yeast rDNA (2-14) and Ty elements (16)(17)(18)(19)(20)(21)(22)(23)(24). regions suggesting that a considerable proportion of the DNA sequence in the vicinity of the 5S genes themselves might be shared.…”

Section: Resultsmentioning

confidence: 99%

“…We show here that a third copy of the variant 5S gene sequence is located adjacent to a member of the Tyl-15 class of yeast transposable genetic elements (14)(15)(16)(17)(18)(19)(20)(21)(22). Throughout this paper "rDNA repeat 5S genes" is used solely in reference to those 5S genes within the 9kb reiterated sequence on Chromosome XII to the exclusion of other 5S genes whether or not these are within junctions between this rDNA and adjacent parts of this chromosome.…”

Section: Introductionmentioning

confidence: 99%

A minor class of 5S rRNA genes inSaccharomyces cerevisiaeX2180-1B, one member of which lies adjacent to a Ty transposable element

1984

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In Saccharomyces cerevisiae the majority of the genes for 5S rRNA lie within a 9kb rDNA sequence that is present as 100-200 tandemly-repeated copies on Chromosome XII. Following our observations that about 10% of yeast 5S rRNA exists as minor variant sequences, we screened a collection of yeast DNA fragments cloned in lambda gt for 5S rRNA genes whose flanking sequences differed from those adjacent to 5S rRNA genes of the rDNA repeat. Three variant 5S rRNA genes were isolated on the basis of such dissimilarity to rDNA repeat sequences. They display a remarkable conservation of their DNA in the vicinity of the 5S coding region, and are examples of a minor form of 5S rRNA coding sequence present in a small number of copies in the yeast genome. These variant sequences appear to be transcribed as efficiently as 5S rRNA genes of the rDNA repeat. In one of our isolates of the variant sequence a Ty transposable element is inserted 145bp upstream of the initiation point for 5S rRNA synthesis.

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“…The two sequences have been aligned to match the alignment of the amino acid sequences of the proteins encoded by these regions (see later; Figure 7). The delta sequences of these two elements are very similar and have been compared previously (28).…”

Section: Yeast Transformationmentioning

confidence: 86%

Variants within the yeast Ty sequence family encode a class of structurally conserved proteins

et al. 1985

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The Ty transposable elements of Saccharomynes cerevisiae form a heterogeneous family within which two broad structural classes (I and II) exist. The two classes differ by two large substitutions and many restriction sites. We show that, like class I elements a class II element, Tyl-17, also appears to contain at least two major protein coding regions, designated TYA and TYB, and the organisational relationship of these regions has been conserved. The TYA genes of both classes encode proteins, designated pl proteins, with an approximate molecular weight of 50 Kd and, despite considerable variation between the TYA regions at the DNA level, the structures of these proteins are remarkably similar. These observations strongly suggest that the pl proteins of Ty elements are functionally significant and that they have been subject to selection.

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Expression of Ty-lacZfusions inSaccharomyces cerevisiae

Cited by 18 publications

References 38 publications

A region internal to the coding sequences is essential for transcription of the yeast Ty-D15 element.

A region internal to the coding sequences is essential for transcription of the yeast Ty-D15 element.

A minor class of 5S rRNA genes inSaccharomyces cerevisiaeX2180-1B, one member of which lies adjacent to a Ty transposable element

Variants within the yeast Ty sequence family encode a class of structurally conserved proteins

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