• Journal of Microbiology and Biotechnology
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• v.13 no.2
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• pp.263-268
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• 2003

Recently, we identified a domain, termed MIRC3-4, for the protein-protein interaction between yeast chitin synthase 3 (CHS3) and chitin synthase 4 (CHS4). In this study, the functional roles of MIRC3-4 were examined at the G1 phase and cytokinesis of the cell cycle by Calcofluor staining and FISH. Some mutations in MIRC3-4 resulted in disappearance of the chitin ring in the early G1 phase, but did not affect chitin synthesis in the cell wall at cytokinesis. The chitin distribution in chs4 mutant cells indicated that CHS4 was involved in the synthesis of chitinring in the G1 phase and in the synthesis of cell wall chitin after cytokinesis, suggesting that Chs4p regulates chitin synthase 3 activity differently in G1 and cytokinesis. Absence of the chitin ring could be caused either by delocalization of Chs3p to the bud-neck or by improper interaction with Chs4p. When mutant cells were immunostained with a Chs3p-specific antibody to discriminate between these two alternatives, the mutated Ch3p was found to localize to the neck in all MIRC3-4 mutants. These results strongly irdicate that Chs4p regulates Chs3p as an activator but not a recruiter.

• Journal of Microbiology and Biotechnology
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• v.12 no.6
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• pp.943-949
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• 2002

It has been proposed that chitin synthase 3 (CHS3)-nediated chitin synthesis during the vegetative cell cycle is regulated by chitin synthase 4 (CHS4) of Saccharomyces cerevisiae. To investigate direct protein-protein interaction between the coding products of these two genes, a domain of Chs3p that is responsible for interaction with Chs4p was identified, using the yeast two-hybrid system. This domain of 54 amino acids, termed MIRC3-4 (Maximum Interacting Region of Chs3p with Chs4p), is well conserved among CHS3 homologs of various fungi. Some mutations in MIRC3-4 resulted in a decrease in the enzymatic activity and chitin contents. Chs3p carrying those mutations exhibited weak interactions with Chs4p, when assayed by the yeast two-hybrid system. Surprisingly, all the mutants were sensitive to Calcofluor regardless of changes in enzymatic activities or chitin contents. This report deals with a core region in MIRC3-4 that affects the interaction with Chs4p.

• Journal of Microbiology
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• v.35 no.3
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• pp.159-164
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• 1997

The phylogenetic study of Penicilium chrysogenum was performed based on amino acid sequence comparison of chitin synthase. Phylogenetic trees were constructed with the deduced amino acid sequences of the highly conserved region of chitin synthease gene fragments amplified by PCR. The BlasP similarity searcch and the bootstrap analysis of the deduced amino acid sequences of chitin synthase from P. chrysogenum with those form other fungi showed a close evolutionary relationship of Penicillium to ascomycetous fungi, especially to genus Aspergilus. The result from bootstrap analysis of the deduced amino acid sequences of the Class II chitin synthase from ascomyceteous fungi supported the usefulness of the Class II chitin synthease for phylogenetic study of filamentous fungi.

• Journal of Microbiology and Biotechnology
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• v.10 no.2
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• pp.251-257
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• 2000

Chitin synthases are identified as key enzymes of chitin biosynthesis in most of the fungi. Among them, chitin synthase II has been reported to be and essential enzyme in chitin biosynthesis, and exists as a membrane-bound form. To search and screen new antifungal agents from natural resources to inhibit chitin synthase II, the assay conditions were established using the enzyme isolated from Saccharomyces cerevisiae ECY38-38A(pAS6) that overproduces only chitin synthase II. This enzyme was activated only by partial proteolysis with trypsin. Its actibity reached the maximum at $80{\;}\mu\textrm{g}/ml$ of trypsin and was strongly stimulated by 2.0 mM $Co^{2+}$, 1.0 nM UDP-[$^{14}C$]-GicNAc, and 32 mM free-GlcNAc. Under these assay conditions, the highest chitin synthase II activity was observed by incubation at $30^{\circ}C$ for 90 min. However, and extremely narrow range of organic solvents up to as much as 25% of DMSO and 25% of MeOH was useful for determining optimal assay conditions. After a search or potent inhibitors of chitin synthase II from natural resources, prodigiosin was isolated from Serratia marcescens and purified by solvent extration and silica gel column chromatographies. The structure of prodigiosin was determined by UV, IR, Mass spectral, and NMR spectral analyses. Its molecular weight and formula were found to be 323 and $C_{20}H_{25}N_{3}O$, respectively. Prodigiosin ingibited chitin synthase II by 50% at the concentration of $115{\;}\mu\textrm{g}/ml$.

• Journal of Microbiology and Biotechnology
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• v.8 no.4
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• pp.422-425
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• 1998

Chitin synthase null-mutants propagate in yeast form in RPMI medium with suppression of hyphal growth. This hyphal suppression is also observed in the wild type culture grown in RPMI medium supplemented with deer antler extract. To identify the possible target of deer antler extract, the enzymatic activities of chitin synthases were examined. The enzymatic activities of three chitin synthases, CAChsl, CAChs2, and CAChs3, were found to be differentially inhibited by deer antler extract. Of them, CAChsl, was the most sensitive to the extract. These results indicate that deer antler extract causes hyphal suppression, which resembles the effects of chitin synthase deletion, probably through direct inhibition of chitin synthases.

• Journal of Microbiology
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• v.35 no.3
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• pp.222-227
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• 1997

DNA fragments homologous to chitin synthase gene were amplified from the genomic DNA of Beauveria brongniartii by PCR using degenerate primers. Cloning and sequencing of the PCR-amplified fragments led to the identification of a gene, designated BbCHSl. Comparison of the deduced amino acid sequence of BbCHSl with those of other Euascomycetes revealed that BbCHSl is a gene for class II chitin synthase. The Blastp search of the deduced amino acid sequence of BbCHSl displayed the highest rate of similarity, 95.8%, with CHS2 of Metarhizium unisopliae. Phylogenetic analysis of the amino acid sequences confirmed the taxonomic and evolutionary position of B. brongniartii, which was previously derived by traditional fungal classification based on morphological features.

• The Korean Journal of Mycology
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• v.25 no.3 s.82
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• pp.167-175
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• 1997

The PCR fragments of two distinct chitin synthase genes, PdCHSl and PdCHS2, were cloned from Penicillium diversum KCTC 6786. The nucleotide sequences of PdCHSl and PdCHS2 contained uninterrupted open reading frames (ORFs) of 570 bp excluding the primer sequence. The similarity analysis of the deduced amino acid sequences using BLASTP indicated that the possible evolutionary relationship between P. diversum and ascomycetous fungi. Multialignment of the deduced amino acid sequences of PdCHSs using CLASTAL W revealed that the PdCHSs fell into two different classes: PdCHSl into Class I and PdCHS2 into Class II of chitin synthase defined by Bowen et al. (1992). By Southern blot analysis, it was shown that each of the two genes is present as a single copy in the genome of P. diversum KCTC 6786.

• Journal of Microbiology and Biotechnology
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• v.7 no.2
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• pp.157-159
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• 1997

A 340-bp chitin synthase gene(CHS) fragment was cloned from the genomic DNA of Pyricularia oryzae using a PCR process with two primer DNAs corresponding to highly conserved sequences within fungal CHS genes. The entire DNA nucleotide sequences of the cloned DNA fragment were determined and analyzed. The amino acid sequences deduced from the nucleotide sequence of the amplified DNA fragment showed 86% homology to that of the Aspergillus fumigatus CHSE gene (9). Using this PCR-amplified DNA, about 2.3 kb of including the PCR fragment of CHSE gene was cloned from genomic library.

• The Korean Journal of Mycology
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• v.26 no.3 s.86
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• pp.354-360
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• 1998

We isolated three amplified DNA fragments from P. sajor-caju by Polmerase chain reaction (PCR) using the chithin synthase specific primers. Since the sequence analysis of the these fragments showed significant homology to the other known chitin synthase gene, we regarded these cloned fragments as PsCHS1, PsCHS2, and PsCHS3 according to their size. The PsCHS3, which showed the highest sequence homology (83% identity in amino acid level with ChsI of Rhizopus oligosporus in conserved region), was selected to see expression pattern of the corresponding gene. The result of RT-PCR using internal primer of the PsCHS3 fragment revealed that PsCHS3 gene was only expressed in cap and mycelium but not in stipe. In order to see whether the PsCHS3 gene was to be induced by wounding, the comparison of the mRNA level of this gene between wounded and unwounded mature cap showed at least two times induction of this gene by wounding treatment.

• Mycobiology
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• v.38 no.2
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• pp.102-107
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• 2010

We identified a gene for $\beta$-1,3-glucan synthesis (GBG1), a nonessential gene whose disruption alters cell wall synthesis enzyme activities and cell wall composition. This gene was cloned by functional complementation of defects in $\beta$-1,3-glucan synthase activity of the the previously isolated Saccharomyces cerevisiae mutant LP0353, which displays a number of cell wall defects at restrictive temperature. Disruption of the GBG1 gene did not affect cell viability or growth rate, but did cause alterations in cell wall synthesis enzyme activities: reduction of $\beta$-1,3-glucan synthase and chitin synthase III activities as well as increased chitin synthase I and II activities. GBG1 disruption also showed altered cell wall composition as well as susceptibility toward cell wall inhibitors such as Zymolyase, Calcofluor white, and Nikkomycin Z. These results indicate that GBG1 plays a role in cell wall biogenesis in S. cerevisiae.