scholarly journals Asymmetric Diversification of Mating Pheromones in Fission Yeast

2018 ◽  
Author(s):  
Taisuke Seike ◽  
Chikashi Shimoda ◽  
Hironori Niki
Keyword(s):  
Reproductive Isolation ◽  
Fission Yeast ◽  
Tandem Repeats ◽  
Amino Acid Sequences ◽  
Close Relative ◽  
Genetic Changes ◽  
Asymmetric System ◽  
Mating Pheromones ◽  
Genes Encoding ◽  
P Factor

AbstractIn fungi, mating between partners critically depends on the molecular recognition of two peptidyl mating pheromones by their respective receptors. The fission yeast Schizosaccharomyces pombe has two mating types, Plus (P) and Minus (M), which secrete two different mating pheromones: P-factor recognized by Mam2, and M-factor recognized by Map3, respectively. Our recent study demonstrated that a few mutations in both M-factor and Map3 can trigger reproductive isolation, a cause of speciation, in S. pombe. Here we explored the mechanism underlying reproductive isolation through genetic changes of pheromones and receptors. We investigated the diversity of genes encoding the pheromones and their receptor in 150 S. pombe wild strains. Whereas the amino acid sequences of M-factor and Map3 were completely conserved, those of P-factor and Mam2 were very diverse. In addition, the P-factor gene contained varying numbers of tandem repeats of P-factor (4–8 repeats). We also explored the recognition specificity of pheromones between S. pombe (Sp) and its close relative Schizosaccharomyces octosporus (So). So-M-factor did not have an effect on S. pombe P-cells, but So-P-factor had a partial effect on S. pombe M-cells, allowing them to mate successfully. Thus, recognition of M-factor seems to be tight, whereas that of P-factor is relatively loose. Moreover, diversity of P-factor and Mam2 might be due to a P-factor-specific peptidase. Overall, the asymmetric system for pheromone recognition in yeasts seems to allow flexible adaptation to mutational changes in the combination of pheromone and receptor while maintaining tight recognition for mating partners.

Diversity of Primary Structures of the Carboxy-terminal Regions of Mammalian Fibrinogen Aα-Chains

1993 ◽  
Vol 69 (04) ◽  
pp. 351-360 ◽  
Author(s):  
Masahiro Murakawa ◽  
Takashi Okamura ◽  
Takumi Kamura ◽  
Tsunefumi Shibuya ◽  
Mine Harada ◽  
...  
Keyword(s):  
Amino Acid ◽  
Rhesus Monkey ◽  
Syrian Hamster ◽  
Tandem Repeats ◽  
Mammalian Species ◽  
Amino Acid Sequences ◽  
Point Of View ◽  
Cross Linking ◽  
Amino Terminal ◽  
Rgd Sequence

SummaryThe partial amino acid sequences of fibrinogen Aα-chains from five mammalian species have been inferred by means of the polymerase chain reaction (PCR). From the genomic DNA of the rhesus monkey, pig, dog, mouse and Syrian hamster, the DNA fragments coding for α-C domains in the Aα-chains were amplified and sequenced. In all species examined, four cysteine residues were always conserved at the homologous positions. The carboxy- and amino-terminal portions of the α-C domains showed a considerable homology among the species. However, the sizes of the middle portions, which corresponded to the internal repeat structures, showed an apparent variability because of several insertions and/or deletions. In the rhesus monkey, pig, mouse and Syrian hamster, 13 amino acid tandem repeats fundamentally similar to those in humans and the rat were identified. In the dog, however, tandem repeats were found to consist of 18 amino acids, suggesting an independent multiplication of the canine repeats. The sites of the α-chain cross-linking acceptor and α2-plasmin inhibitor cross-linking donor were not always evolutionally conserved. The arginyl-glycyl-aspartic acid (RGD) sequence was not found in the amplified region of either the rhesus monkey or the pig. In the canine α-C domain, two RGD sequences were identified at the homologous positions to both rat and human RGD S. In the Syrian hamster, a single RGD sequence was found at the same position to that of the rat. Triplication of the RGD sequences was seen in the murine fibrinogen α-C domain around the homologous site to the rat RGDS sequence. These findings are of some interest from the point of view of structure-function and evolutionary relationships in the mammalian fibrinogen Aα-chains.

scholarly journals Elevated Sporulation Efficiency in Fission Yeast Schizosaccharomyces japonicus Strains Isolated from Drosophila

2021 ◽  
Vol 7 (5) ◽  
pp. 350
Author(s):  
Taisuke Seike ◽  
Natsue Sakata ◽  
Fumio Matsuda ◽  
Chikara Furusawa
Keyword(s):  
Signal Transduction ◽  
Fission Yeast ◽  
High Frequency ◽  
Type Strain ◽  
Hyphal Growth ◽  
Amino Acid Sequences ◽  
Iodine Vapor ◽  
Sporulation Efficiency ◽  
Yeast Ecology ◽  
Wild Strains

The fission yeast Schizosaccharomyces japonicus, comprising S. japonicus var. japonicus and S. japonicus var. versatilis varieties, has unique characteristics such as striking hyphal growth not seen in other Schizosaccharomyces species; however, information on its diversity and evolution, in particular mating and sporulation, remains limited. Here we compared the growth and mating phenotypes of 17 wild strains of S. japonicus, including eight S. japonicus var. japonicus strains newly isolated from an insect (Drosophila). Unlike existing wild strains isolated from fruits/plants, the strains isolated from Drosophila sporulated at high frequency even under nitrogen-abundant conditions. In addition, one of the strains from Drosophila was stained by iodine vapor, although the type strain of S. japonicus var. japonicus is not stained. Sequence analysis further showed that the nucleotide and amino acid sequences of pheromone-related genes have diversified among the eight strains from Drosophila, suggesting crossing between S. japonicus cells of different genetic backgrounds occurs frequently in this insect. Much of yeast ecology remains unclear, but our findings suggest that insects such as Drosophila might be a good niche for mating and sporulation, and will provide a basis for the understanding of sporulation mechanisms via signal transduction, as well as the ecology and evolution of yeast.

Direct cloning of genes encoding novel xylanases from the human gut

2005 ◽  
Vol 51 (3) ◽  
pp. 251-259 ◽  
Author(s):  
Hidenori Hayashi ◽  
Takashi Abe ◽  
Mitsuo Sakamoto ◽  
Hiroki Ohara ◽  
Toshimichi Ikemura ◽  
...  
Keyword(s):  
Intestinal Bacteria ◽  
Fecal Microbiota ◽  
Coli Strain ◽  
Amino Acid Sequences ◽  
Self Organizing Map ◽  
Human Gut ◽  
Gene Encoding ◽  
Genes Encoding ◽  
Ph Range ◽  
Self Organizing

The aim of this study was to identify a novel 1,4-β-xylanase gene from the mixed genome DNA of human fecal bacteria without bacterial cultivation. Total DNA was isolated from a population of bacteria extracted from fecal microbiota. Using PCR, the gene fragments encoding 5 different family 10 xylanases (xyn10A, xyn10B, xyn10C, xyn10D, and xyn10E) were found. Amino acid sequences deduced from these genes were highly homologous with those of xylanases from anaerobic intestinal bacteria such as Bacteroides spp. and Prevotella spp. Self-organizing map (SOM) analysis revealed that xynA10 was classified into Bacteroidetes. To confirm that one of these genes encodes an active enzyme, a full-length xyn10A gene was obtained using nested primers specific to the internal fragments and random primers. The xyn10A gene encoding the xylanase Xyn10A consists of 1146 bp and encodes a protein of 382 amino acids and a molecular weight of 43 552. Xyn10A was a single module novel xylanase. Xyn10A was purified from a recombinant Escherichia coli strain and characterized. This enzyme was optimally active at 40 °C and stable up to 50 °C at pH 6.5 and over the pH range 4.0–11.0 at 25 °C. In addition, 2 ORFs (ORF1 and ORF2) were identified upstream of xyn10A. These results suggested that many unidentified xylanolytic bacteria exist in the human gut and may contribute to the breakdown of xylan which contains dietary fiber.Key words: xylanase, human gut, fecal microbiota, phylogenetic analysis, self-organizing map.

The Physiology of Body Weight Regulation: Relevance to the Etiology of Obesity in Children

PEDIATRICS ◽  
1998 ◽  
Vol 101 (Supplement_2) ◽  
pp. 525-539 ◽  
Author(s):  
Michael Rosenbaum ◽  
Rudolph L. Leibel
Keyword(s):  
United States ◽  
Body Weight ◽  
Environmental Factors ◽  
Regulatory System ◽  
The United States ◽  
Genetic Changes ◽  
Adult Body ◽  
Genes Encoding ◽  
Prevalence Of Obesity ◽  
Obesity In Children

The prevalence of obesity in children and adults in the United States has increased by more than 30% over the past decade. Recent studies of the physiology and molecular genetics of obesity in humans have provided evidence that body weight (fat) is regulated. Some of the genes encoding the molecular components of this regulatory system have been isolated from rodents. The increasing prevalence of obesity in the United States apparently represents the interaction of these genes with an environment that encourages a sedentary lifestyle and consumption of calories. The rapid increase in the prevalence of obesity emphasizes the role of environmental factors, because genetic changes could not occur at this rate. Thus, understanding of the relevant genes and how their effects are mediated by environment and development should lead to more effective prophylaxis and therapy of obesity. Although no clear environmental factors have been identified as causative of obesity, the rapid increases in the prevalence of obesity and the seeming voluntary immutability of adult body fatness can be taken as tacit evidence that the pediatric environment can be altered in a way that affects adult body weight.

Structural and antigenic polymorphism of the 35- to 48-kilodalton merozoite surface antigen (MSA-2) of the malaria parasite Plasmodium falciparum

1991 ◽  
Vol 11 (2) ◽  
pp. 963-971
Author(s):  
B Fenton ◽  
J T Clark ◽  
C M Khan ◽  
J V Robinson ◽  
D Walliker ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Amino Acid ◽  
Surface Antigen ◽  
Dna Sequences ◽  
Amino Acid Sequences ◽  
Merozoite Surface Antigen ◽  
Parasite Plasmodium ◽  
Genes Encoding ◽  
Parasite Plasmodium Falciparum ◽  
Group B

Merozoite surface antigen MSA-2 of the human parasite Plasmodium falciparum is being considered for the development of a malaria vaccine. The antigen is polymorphic, and specific monoclonal antibodies differentiate five serological variants of MSA-2 among 25 parasite isolates. The variants are grouped into two major serogroups, A and B. Genes encoding two different variants from serogroup A have been sequenced, and their DNA together with deduced amino acid sequences were compared with sequences encoded by other alleles. The comparison shows that the serological classification reflects differences in DNA sequences and deduced primary structure of MSA-2 variants and serogroups. Thus, the overall homologies of DNA and amino acid sequences are over 95% among variants in the same serogroup. In contrast, similarities between the group A variants and a group B variant are only 70 and 64% for DNA and amino acid sequences, respectively. We propose that the MSA-2 protein is encoded by two highly divergent groups of alleles, with limited additional polymorphism displayed within each group.

scholarly journals Comparative genomics reveals the molecular determinants of rapid growth of the cyanobacteriumSynechococcus elongatusUTEX 2973

2018 ◽  
Vol 115 (50) ◽  
pp. E11761-E11770 ◽  
Author(s):  
Justin Ungerer ◽  
Kristen E. Wendt ◽  
John I. Hendry ◽  
Costas D. Maranas ◽  
Himadri B. Pakrasi
Keyword(s):  
Growth Rate ◽  
Photosynthetic Rate ◽  
Rapid Growth ◽  
Mutational Analysis ◽  
Specific Activity ◽  
Synechococcus Elongatus ◽  
Fast Growth ◽  
Close Relative ◽  
Genetic Changes ◽  
Photosynthetic Productivity

Cyanobacteria are emerging as attractive organisms for sustainable bioproduction. We previously describedSynechococcus elongatusUTEX 2973 as the fastest growing cyanobacterium known.Synechococcus2973 exhibits high light tolerance and an increased photosynthetic rate and produces biomass at three times the rate of its close relative, the model strainSynechococcus elongatus7942. The two strains differ at 55 genetic loci, andsome of these loci must contain the genetic determinants of rapid photoautotrophic growth and improved photosynthetic rate. Using CRISPR/Cpf1, we performed a comprehensive mutational analysis ofSynechococcus2973 and identified three specific genes,atpA,ppnK, andrpaA, with SNPs that confer rapid growth. The fast-growth–associated allele of each gene was then used to replace the wild-type alleles inSynechococcus7942. Upon incorporation, each allele successively increased the growth rate ofSynechococcus7942; remarkably, inclusion of all three alleles drastically reduced the doubling time from 6.8 to 2.3 hours. Further analysis revealed that our engineering effort doubled the photosynthetic productivity ofSynechococcus7942. We also determined that the fast-growth–associated allele ofatpAyielded an ATP synthase with higher specific activity, while that ofppnKencoded a NAD+kinase with significantly improved kinetics. TherpaASNPs cause broad changes in the transcriptional profile, as this gene is the master output regulator of the circadian clock. This pioneering study has revealed the molecular basis for rapid growth, demonstrating that limited genetic changes can dramatically improve the growth rate of a microbe by as much as threefold.

Identification of an alpha-tubulin mutant of fission yeast from gamma-tubulin-interacting protein screening: genetic evidence for alpha-/gamma-tubulin interaction

2000 ◽  
Vol 113 (24) ◽  
pp. 4557-4562 ◽  
Author(s):  
A. Takeoka ◽  
M. Shimizu ◽  
T. Horio
Keyword(s):  
Fission Yeast ◽  
Central Element ◽  
Direct Interaction ◽  
Interacting Proteins ◽  
Microtubule Nucleation ◽  
Mutation Site ◽  
Interacting Protein ◽  
Alpha Tubulin ◽  
Genes Encoding ◽  
Gamma Tubulin

gamma-Tubulin has been determined to be a central element of microtubule nucleation and, thus, indispensable for cellular organization of the microtubule. Utilizing the fact that human gamma-tubulin can function in the fission yeast Schizosaccharomyces pombe, we have generated a unique mutant screening procedure which can specifically select mutants of genes encoding gamma-tubulin-interacting proteins. One of the isolated mutants, cs76, turned out to carry a mutation in the alpha 1-tubulin gene (nda2(+)). This result suggests a direct interaction between the alpha- and gamma-tubulins. We located the mutation site in the nda2 gene and characterized the mutant phenotype. Our results demonstrate the importance of the alpha-/gamma-tubulin interaction in microtubule nucleation and should complement previous knowledge.

Analysis of the structural genes encoding M-factor in the fission yeast Schizosaccharomyces pombe: identification of a third gene, mfm3

1994 ◽  
Vol 14 (6) ◽  
pp. 3895-3905
Author(s):  
S Kjaerulff ◽  
J Davey ◽  
O Nielsen
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Mutational Analysis ◽  
M Cells ◽  
Gene Products ◽  
Structural Genes ◽  
Triple Mutant ◽  
Isolation And Characterization ◽  
Genes Encoding

We previously identified two genes, mfm1 and mfm2, with the potential to encode the M-factor mating pheromone of the fission yeast Schizosaccharomyces pombe (J. Davey, EMBO J. 11:951-960, 1992), but further analysis revealed that a mutant strain lacking both genes still produced active M-factor. Here we describe the isolation and characterization of a third M-factor gene, mfm3. A mutant lacking all three genes fails to produce M-factor, indicating that all functional M-factor genes now have been identified. The triple mutant exhibits an absolute mating defect in M cells, a defect that is not rescued by addition of exogenous M-factor. A mutational analysis reveals that all three mfm genes contribute to the production of M-factor. Their transcription is limited to M cells and requires the mat1-Mc and ste11 gene products. Each gene is induced when the cells are starved of nitrogen and further induced by a pheromone signal. Additionally, the signal transduction machinery associated with the pheromone response is required for transcription of the mfm genes in both stimulated and unstimulated cells.

scholarly journals Cloning and Characterization of Two Xyloglucanases from Paenibacillus sp. Strain KM21

2005 ◽  
Vol 71 (12) ◽  
pp. 7670-7678 ◽  
Author(s):  
Katsuro Yaoi ◽  
Tomonori Nakai ◽  
Yoshiro Kameda ◽  
Ayako Hiyoshi ◽  
Yasushi Mitsuishi
Keyword(s):  
Glycoside Hydrolase ◽  
Amino Acid Sequences ◽  
Glycoside Hydrolase Family ◽  
Carbohydrate Binding ◽  
Carbohydrate Binding Module ◽  
C Terminus ◽  
Paenibacillus Sp ◽  
Genes Encoding ◽  
Molecular Masses

ABSTRACT Two xyloglucan-specific endo-β-1,4-glucanases (xyloglucanases [XEGs]), XEG5 and XEG74, with molecular masses of 40 kDa and 105 kDa, respectively, were isolated from the gram-positive bacterium Paenibacillus sp. strain KM21, which degrades tamarind seed xyloglucan. The genes encoding these XEGs were cloned and sequenced. Based on their amino acid sequences, the catalytic domains of XEG5 and XEG74 were classified in the glycoside hydrolase families 5 and 74, respectively. XEG5 is the first xyloglucanase belonging to glycoside hydrolase family 5. XEG5 lacks a carbohydrate-binding module, while XEG74 has an X2 module and a family 3 type carbohydrate-binding module at its C terminus. The two XEGs were expressed in Escherichia coli, and recombinant forms of the enzymes were purified and characterized. Both XEGs had endoglucanase active only toward xyloglucan and not toward Avicel, carboxymethylcellulose, barley β-1,3/1,4-glucan, or xylan. XEG5 is a typical endo-type enzyme that randomly cleaves the xyloglucan main chain, while XEG74 has dual endo- and exo-mode activities or processive endo-mode activity. XEG5 digested the xyloglucan oligosaccharide XXXGXXXG to produce XXXG, whereas XEG74 digestion of XXXGXXXG resulted in XXX, XXXG, and GXXXG, suggesting that this enzyme cleaves the glycosidic bond of unbranched Glc residues. Analyses using various oligosaccharide structures revealed that unique structures of xyloglucan oligosaccharides can be prepared with XEG74.

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