scholarly journals The centromeric K-type repeat and the central core are together sufficient to establish a functional Schizosaccharomyces pombe centromere.

1994 ◽  
Vol 5 (7) ◽  
pp. 747-761 ◽  
Author(s):  
M Baum ◽  
V K Ngan ◽  
L Clarke
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Dna Sequences ◽  
Specific Protein ◽  
Central Core ◽  
Critical Elements ◽  
Centromere Function ◽  
Centromeric Repeat ◽  
Proposed Model ◽  
Kinetochore Function

The DNA requirements for centromere function in fission yeast have been investigated using a minichromosome assay system. Critical elements of Schizosaccharomyces pombe centromeric DNA are portions of the centromeric central core and sequences within a 2.1-kilobase segment found on all three chromosomes as part of the K-type (K/K"/dg) centromeric repeat. The S. pombe centromeric central core contains DNA sequences that appear functionally redundant, and the inverted repeat motif that flanks the central core in all native fission yeast centromeres is not essential for centromere function in circular minichromosomes. Tandem copies of centromeric repeat K", in conjunction with the central core, exert an additive effect on centromere function, increasing minichromosome mitotic stability with each additional copy. Centromeric repeats B and L, however, and parts of the central core and its core-associated repeat are dispensable and cannot substitute for K-type sequences. Several specific protein binding sites have been identified within the centromeric K-type repeat, consistent with a recently proposed model for centromere/kinetochore function in S. pombe.

Structural organization and functional analysis of centromeric DNA in the fission yeast Schizosaccharomyces pombe

1988 ◽  
Vol 8 (2) ◽  
pp. 754-763
Author(s):  
B Fishel ◽  
H Amstutz ◽  
M Baum ◽  
J Carbon ◽  
L Clarke
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Dna Sequences ◽  
Centromeric Dna ◽  
Centromere Function ◽  
Leu2 Gene ◽  
Centromeric Repeat ◽  
Sequence Elements ◽  
Chromosome Iii ◽  
Chromosome Ii

Centromeric DNA in the fission yeast Schizosaccharomyces pombe was isolated by chromosome walking and by field inversion gel electrophoretic fractionation of large genomic DNA restriction fragments. The centromere regions of the three chromosomes were contained on three SalI fragments (120 kilobases [kb], chromosome III; 90 kb, chromosome II; and 50 kb, chromosome I). Each fragment contained several repetitive DNA sequences, including repeat K (6.4 kb), repeat L (6.0 kb), and repeat B, that occurred only in the three centromere regions. On chromosome II, these repeats were organized into a 35-kb inverted repeat that included one copy of K and L in each arm of the repeat. Site-directed integration of a plasmid containing the yeast LEU2 gene into K repeats at each of the centromeres or integration of an intact K repeat into a chromosome arm had no effect on mitotic or meiotic centromere function. The centromeric repeat sequences were not transcribed and possessed many of the properties of constitutive heterochromatin. Thus, S. pombe is an excellent model system for studies on the role of repetitive sequence elements in centromere function.

scholarly journals Structural organization and functional analysis of centromeric DNA in the fission yeast Schizosaccharomyces pombe.

1988 ◽  
Vol 8 (2) ◽  
pp. 754-763 ◽  
Author(s):  
B Fishel ◽  
H Amstutz ◽  
M Baum ◽  
J Carbon ◽  
L Clarke
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Dna Sequences ◽  
Centromeric Dna ◽  
Centromere Function ◽  
Leu2 Gene ◽  
Centromeric Repeat ◽  
Sequence Elements ◽  
Chromosome Iii ◽  
Chromosome Ii

Centromeric DNA in the fission yeast Schizosaccharomyces pombe was isolated by chromosome walking and by field inversion gel electrophoretic fractionation of large genomic DNA restriction fragments. The centromere regions of the three chromosomes were contained on three SalI fragments (120 kilobases [kb], chromosome III; 90 kb, chromosome II; and 50 kb, chromosome I). Each fragment contained several repetitive DNA sequences, including repeat K (6.4 kb), repeat L (6.0 kb), and repeat B, that occurred only in the three centromere regions. On chromosome II, these repeats were organized into a 35-kb inverted repeat that included one copy of K and L in each arm of the repeat. Site-directed integration of a plasmid containing the yeast LEU2 gene into K repeats at each of the centromeres or integration of an intact K repeat into a chromosome arm had no effect on mitotic or meiotic centromere function. The centromeric repeat sequences were not transcribed and possessed many of the properties of constitutive heterochromatin. Thus, S. pombe is an excellent model system for studies on the role of repetitive sequence elements in centromere function.

scholarly journals The centromere enhancer mediates centromere activation in Schizosaccharomyces pombe.

1997 ◽  
Vol 17 (6) ◽  
pp. 3305-3314 ◽  
Author(s):  
V K Ngan ◽  
L Clarke
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Chromosome Segregation ◽  
Dna Sequences ◽  
Direct Evidence ◽  
Central Core ◽  
Specific Sequence ◽  
Circular Dna ◽  
Centromere Function

The centromere enhancer is a functionally important DNA region within the Schizosaccharomyces pombe centromeric K-type repeat. We have previously shown that addition of the enhancer and cen2 centromeric central core to a circular minichromosome is sufficient to impart appreciable centromere function. A more detailed analysis of the enhancer shows that it is dispensable for centromere function in a cen1-derived minichromosome containing the central core and the remainder of the K-type repeat, indicating that the critical centromeric K-type repeat, like the central core, is characterized by functional redundancy. The centromeric enhancer is required, however, for a central core-carrying minichromosome to exhibit immediate centromere activity when the circular DNA is introduced via transformation into S. pombe. This immediate activation is probably a consequence of a centromere-targeted epigenetic system that governs the chromatin architecture of the region. Moreover, our studies show that two entirely different DNA sequences, consisting of elements derived from two native centromeres, can display centromere function. An S. pombe CENP-B-like protein, Abp1p/Cbp1p, which is required for proper chromosome segregation in vivo, binds in vitro to sites within and adjacent to the modular centromere enhancer, as well as within the centromeric central cores. These results provide direct evidence in fission yeast of a model, similar to one proposed for mammalian systems, whereby no specific sequence is necessary for centromere function but certain classes of sequences are competent to build the appropriate chromatin foundation upon which the centromere/kinetochore can be formed and activated.

Identification of DNA regions required for mitotic and meiotic functions within the centromere of Schizosaccharomyces pombe chromosome I

1991 ◽  
Vol 11 (4) ◽  
pp. 2206-2215
Author(s):  
K M Hahnenberger ◽  
J Carbon ◽  
L Clarke
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Sister Chromatid ◽  
Inverted Repeat ◽  
Distal Portion ◽  
Central Core ◽  
Inverted Repeat Region ◽  
Artificial Chromosomes ◽  
Centromere Function ◽  
Chromosome I ◽  
Meiosis I

We have determined the structural organization and functional roles of centromere-specific DNA sequence repeats in cen1, the centromere region from chromosome I of the fission yeast Schizosaccharomyces pombe. cen1 is composed of various classes of repeated sequences designated K', K"(dgl), L, and B', arranged in a 34-kb inverted repeat surrounding a 4- to 5-kb nonhomologous central core. Artificial chromosomes containing various portions of the cen1 region were constructed and assayed for mitotic and meiotic centromere function in S. pombe. Deleting K' and L from the distal portion of one arm of the inverted repeat had no effect on mitotic centromere function but resulted in greatly increased precocious sister chromatid separation in the first meiotic division. A centromere completely lacking K' and L, but containing the central core, one copy of B' and K" in one arm, and approximately 2.5 kb of the core-proximal portion of B' in the other arm, was also fully functional mitotically but again did not maintain sister chromatid attachment in meiosis I. However, deletion of K" from this minichromosome resulted in complete loss of centromere function. Thus, one copy of at least a portion of the K" (dgl) repeat is absolutely required but is not sufficient for S. pombe centromere function. The long centromeric inverted-repeat region must be relatively intact to maintain sister chromatid attachment in meiosis I.

scholarly journals Identification of DNA regions required for mitotic and meiotic functions within the centromere of Schizosaccharomyces pombe chromosome I.

1991 ◽  
Vol 11 (4) ◽  
pp. 2206-2215 ◽  
Author(s):  
K M Hahnenberger ◽  
J Carbon ◽  
L Clarke
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Sister Chromatid ◽  
Inverted Repeat ◽  
Distal Portion ◽  
Central Core ◽  
Inverted Repeat Region ◽  
Artificial Chromosomes ◽  
Centromere Function ◽  
Chromosome I ◽  
Meiosis I

We have determined the structural organization and functional roles of centromere-specific DNA sequence repeats in cen1, the centromere region from chromosome I of the fission yeast Schizosaccharomyces pombe. cen1 is composed of various classes of repeated sequences designated K', K"(dgl), L, and B', arranged in a 34-kb inverted repeat surrounding a 4- to 5-kb nonhomologous central core. Artificial chromosomes containing various portions of the cen1 region were constructed and assayed for mitotic and meiotic centromere function in S. pombe. Deleting K' and L from the distal portion of one arm of the inverted repeat had no effect on mitotic centromere function but resulted in greatly increased precocious sister chromatid separation in the first meiotic division. A centromere completely lacking K' and L, but containing the central core, one copy of B' and K" in one arm, and approximately 2.5 kb of the core-proximal portion of B' in the other arm, was also fully functional mitotically but again did not maintain sister chromatid attachment in meiosis I. However, deletion of K" from this minichromosome resulted in complete loss of centromere function. Thus, one copy of at least a portion of the K" (dgl) repeat is absolutely required but is not sufficient for S. pombe centromere function. The long centromeric inverted-repeat region must be relatively intact to maintain sister chromatid attachment in meiosis I.

scholarly journals Functional analysis of a centromere from fission yeast: a role for centromere-specific repeated DNA sequences.

1990 ◽  
Vol 10 (5) ◽  
pp. 1863-1872 ◽  
Author(s):  
L Clarke ◽  
M P Baum
Keyword(s):  
Dna Sequences ◽  
Inverted Repeat ◽  
Repeated Sequence ◽  
Repeated Sequences ◽  
Central Core ◽  
Repeated Dna ◽  
Inverted Repeat Region ◽  
Repeated Dna Sequences ◽  
Centromere Function ◽  
Chromosome Ii

A circular minichromosome carrying functional centromere sequences (cen2) from Schizosaccharomyces pombe chromosome II behaves as a stable, independent genetic linkage group in S. pombe. The cen2 region was found to be organized into four large tandemly repeated sequence units which span over 80 kilobase pairs (kb) of untranscribed DNA. Two of these units occurred in a 31-kb inverted repeat that flanked a 7-kb central core of nonhomology. The inverted repeat region had centromere function, but neither the central core alone nor one arm of the inverted repeat was functional. Deletion of a portion of the repeated sequences that flank the central core had no effect on mitotic segregation functions or on meiotic segregation of a minichromosome to two of the four haploid progeny, but drastically impaired centromere-mediated maintenance of sister chromatid attachment in meiosis I. This requirement for centromere-specific repeated sequences could not be satisfied by introduction of random DNA sequences. These observations suggest a function for the heterochromatic repeated DNA sequences found in the centromere regions of higher eucaryotes.

scholarly journals Organization, primary structure, and evolution of histone H2A and H2B genes of the fission yeast Schizosaccharomyces pombe.

1985 ◽  
Vol 5 (11) ◽  
pp. 3261-3269 ◽  
Author(s):  
J Choe ◽  
T Schuster ◽  
M Grunstein
Keyword(s):  
Amino Acid ◽  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Dna Sequences ◽  
Sequence Evolution ◽  
Hydrophobic Core ◽  
Histone H2a ◽  
Acid Protein ◽  
Close Proximity ◽  
Pair Sequence

The histone H2A and H2B genes of the fission yeast Schizosaccharomyces pombe were cloned and sequenced. Southern blot and sequence analyses showed that, unlike other eucaryotes, Saccharomyces cerevisiae included, S. pombe has unequal numbers of these genes, containing two histone H2A genes (H2A-alpha and -beta) and only one H2B gene (H2B-alpha) per haploid genome. H2A- and H2B-alpha are adjacent to each other and are divergently transcribed. H2A-beta has no other histone gene in close proximity. Preceding both H2A-alpha and -beta is a highly conserved 19-base-pair sequence (5'-CATCAC/AAACCCTAACCCTG-3'). The H2A DNA sequences encode two histone H2A subtypes differing in amino acid sequence (three residues) and size (H2A-alpha, 131 residues; H2A-beta, 130 residues). H2B-alpha codes for a 125-amino-acid protein. Sequence evolution is extensive between S. pombe and S. cerevisiae and displays unique patterns of divergence. Certain N-terminal sequences normally divergent between eucaryotes are conserved between the two yeasts. In contrast, the normally conserved hydrophobic core of H2A is as divergent between the yeasts as between S. pombe and calf.

scholarly journals Budding yeast centromeric DNA and A+T rich bacterial DNA can function as centromeres in the fission yeast Schizosaccharomyces pombe

2019 ◽  
Author(s):  
Anne C Barbosa ◽  
Zhengyao Xu ◽  
Kazhal Karari ◽  
Silke Hauf ◽  
William RA Brown
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Dna Sequence ◽  
Budding Yeast ◽  
Bacterial Dna ◽  
Centromeric Dna ◽  
Serine Recombinases ◽  
Centromere Function ◽  
And Function

Eukaryotic centromeric DNA is famously variable in evolution but currently, this cannot be reconciled with the conservation of eukaryotic centromere function. It seems likely that centromeric DNA from different organisms contains conserved functionally important features but the identity of these features is unknown. The point centromeres of the budding yeast Saccharomyces cerevisiae and the regional centromeres of the fission yeast Schizosaccharomyces pombe are separated by 350 million years of evolution and are canonical examples of the paradoxical relationship1 between centromeric DNA sequence and function. We have established a centromere-replacement strategy in Schizosaccharomyces pombe in order to resolve this paradox experimentally. Centromere-replacement shows that an A+T rich bacterial DNA sequence has weak centromere function and that elements of the Saccharomyces cerevisiae centromere embedded in short sequences from the non-centromeric S. pombe wee1 gene function almost as well as native S. pombe centromeric DNA. These observations demonstrate that determinants of centromere function are held in common by the budding and fission yeasts and that A+T rich DNA is both necessary and sufficient for function in S. pombe. Given the evolutionary distance between these yeasts, it is likely that A+T rich DNA has centromere function in a wide variety of eukaryotes. Centromere-replacement uses unidirectional serine recombinases that work well in many organisms2 3 and our experimental strategy should allow this idea to be tested in other eukaryotes.

scholarly journals The chromatin structure of centromeres from fission yeast: differentiation of the central core that correlates with function.

1991 ◽  
Vol 112 (2) ◽  
pp. 191-201 ◽  
Author(s):  
C Polizzi ◽  
L Clarke
Keyword(s):  
Fission Yeast ◽  
Dna Sequences ◽  
Chromatin Structure ◽  
Chromatin Organization ◽  
Repeated Sequences ◽  
Central Core ◽  
Repeated Dna ◽  
Structural Differentiation ◽  
Yeast Saccharomyces Cerevisiae ◽  
Repeated Dna Sequences

We have examined the chromatin structure of centromere regions from the fission yeast Schizosaccharomyces pombe. The large and complex centromere regions of the S. pombe chromosomes encompass many kilobase pairs of DNA and contain several classes of tandemly repeated DNA sequences. The repeated sequences are further organized into a large inverted repeat flanking a central core, a conserved structural feature among all three centromeres in S. pombe. The nucleosomal configuration of the centromere regions is nonuniform and highly varied. Most of the centromere-specific repeated DNA sequences are packaged into nucleosomes typical of bulk chromatin. However, the central core and core-associated repeated sequences from the centromere regions of chromosomes I (cen1) and II (cen2), when present in S. pombe, show an altered chromatin structure, with little or no evidence of regular nucleosomal packaging. The atypical chromatin organization of the cen2 central core is not due to transcription, as no transcripts from this region were detected. These same DNA sequences, however, are packaged into nucleosomes typical of bulk chromatin when present in a nonfunctional environment on a minichromosome in the budding yeast Saccharomyces cerevisiae. Because the cen2 central core sequences themselves do not preclude regular nucleosomal packaging, we speculate that in S. pombe they constitute a specialized site of kinetochore protein assembly. The atypical nucleosomal pattern of the cen2 central core remains constant during the cell cycle, with only minor differences observed for some sequences. We propose that the unusual chromatin organization of the core region forms the basis of a higher order structural differentiation that distinguishes the centromere from the chromosome arms and specifies the essential structure for centromere function.

Organization, primary structure, and evolution of histone H2A and H2B genes of the fission yeast Schizosaccharomyces pombe

1985 ◽  
Vol 5 (11) ◽  
pp. 3261-3269
Author(s):  
J Choe ◽  
T Schuster ◽  
M Grunstein
Keyword(s):  
Amino Acid ◽  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Dna Sequences ◽  
Sequence Evolution ◽  
Hydrophobic Core ◽  
Histone H2a ◽  
Acid Protein ◽  
Close Proximity ◽  
Pair Sequence

The histone H2A and H2B genes of the fission yeast Schizosaccharomyces pombe were cloned and sequenced. Southern blot and sequence analyses showed that, unlike other eucaryotes, Saccharomyces cerevisiae included, S. pombe has unequal numbers of these genes, containing two histone H2A genes (H2A-alpha and -beta) and only one H2B gene (H2B-alpha) per haploid genome. H2A- and H2B-alpha are adjacent to each other and are divergently transcribed. H2A-beta has no other histone gene in close proximity. Preceding both H2A-alpha and -beta is a highly conserved 19-base-pair sequence (5'-CATCAC/AAACCCTAACCCTG-3'). The H2A DNA sequences encode two histone H2A subtypes differing in amino acid sequence (three residues) and size (H2A-alpha, 131 residues; H2A-beta, 130 residues). H2B-alpha codes for a 125-amino-acid protein. Sequence evolution is extensive between S. pombe and S. cerevisiae and displays unique patterns of divergence. Certain N-terminal sequences normally divergent between eucaryotes are conserved between the two yeasts. In contrast, the normally conserved hydrophobic core of H2A is as divergent between the yeasts as between S. pombe and calf.

Sign in / Sign up

Export Citation Format

Share Document