Abstract: This invention provides a means for high-level secretory production of a protein, and, in particular, a protein having a complicated structure such as an antibody, in a host cell such as a yeast cell. This invention provides a method for high-level secretory production of a foreign protein with the use of a transformed host cell having one or more types of chaperone protein genes and via suppression of O sugar chain inherent to a host cell such as a yeast cell.

Abstract: The present invention enables screening for compounds that inhibit the transport of GPI-anchored proteins to fungal cell walls, using a simple assay for transacylation to GlcN-PI using membrane fraction expressing GWT1 protein. New antifungal agents can be created that inhibit the synthesis of fungal cell walls and also inhibit adhesion to host cells by inhibiting the transport of GPI-anchored proteins to fungal cell walls.

Abstract: This invention provides a means for enabling high-level secretory production of proteins, in particular proteins having complicated structures such as antibodies, in host cells such as yeast cells. The invention also provides transformed yeast cells having the activated HAC1 gene and the RRBP1 gene and a method for enabling high-level secretory production of foreign proteins using such transformed host cells by inhibiting O-sugar chain formation indigenous to host cells such as yeast cells.

Abstract: This invention is to provide a process for producing a glycoprotein comprising a mammalian type sugar chain, characterized in that the process comprises introducing an ?-1,2-mannosidase gene into a methylotrophic yeast having a mutation of a sugar chain biosynthesizing enzyme gene, so that the ?-1,2-mannosidase gene is expressed under the control of a potent promoter in the yeast; culturing in a medium the methylotrophic yeast cells with a heterologous gene transferred thereinto; and obtaining the glycoprotein comprising a mammalian type sugar chain from the culture. Using the newly created methylotrophic yeast having a sugar chain mutation, a neutral sugar chain identical with a high mannose type sugar chain produced by mammalian cells such as human cells, or a glycoprotein comprising such a neutral sugar chain, can be produced in a large amount at a high purity.

Abstract: This invention provides a means for high-level secretory production of a protein, and, in particular, a protein having a complicated structure such as an antibody, in a host cell such as a yeast cell. This invention provides a method for high-level secretory production of a foreign protein with the use of a transformed host cell having one or more types of chaperone protein genes and via suppression of O sugar chain inherent to a host cell such as a yeast cell.

Abstract: A method for breeding yeast having thermotolerance or recovering growth activity and a method for breeding yeast which produces beta-glucan efficiently as well as an yeast obtained by such methods for breeding are presented by a method for breeding yeast having thermotolerance or recovering growth activity including a step for controlling proofreading function of DNA polymerase in a loss-of-function mutant of yeast (for example, a step for including mutant pol3 gene or mutant cdc6? gene in a gene-disruptant.

Abstract: This invention provides proteins and genes thereof involved in the GPI lipid remodeling process and, thereby and constructing a system for screening for useful substances such as anticancer agents and a system for detecting abnormalities in the GPI lipid remodeling process.

Abstract: A process for producing a lysosomal enzyme having a mannose-6-phosphate-containing acidic sugar chain, wherein the process comprising: culturing in a medium yeast cells obtained by introducing a lysosomal enzyme gene into a sugar chain biosynthetic enzyme gene mutant strain of yeast, collecting a lysosomal enzyme having a phosphate-containing sugar chain from the culture, and then treating the enzyme with ?-mannosidase; and pharmaceutical compositions for treatment of human lysosomal enzyme deficiencies produced by the process. The genetic engineering technique using the yeast according to the present invention allows large-amount and high-purity production of a glycoprotein having a phosphate-containing acidic sugar chain which can serve as a labeling marker for transporting into lysosomes in cells of mammals such as human. The glycoprotein having a phosphate-containing acidic sugar chain according to the invention may be utilized as a drug effective in treatment of human lysosomal enzyme deficiencies, etc.

Abstract: This invention provides a means for enabling high-level secretory production of proteins, in particular proteins having complicated structures such as antibodies, in host cells such as yeast cells. The invention also provides transformed yeast cells having the activated HAC1 gene and the RRBP1 gene and a method for enabling high-level secretory production of foreign proteins using such transformed host cells by inhibiting O-sugar chain formation indigenous to host cells such as yeast cells.

Abstract: The present invention relates to a means for generating a mucin-type glycopeptide or glycoprotein on a large scale in yeast. Specifically, the invention relates to a method which comprises introducing into a yeast at least one selected from the group consisting of a gene encoding UDP-GalNAc synthetase, a gene encoding UDP-GalNAc transporter, and a gene encoding polypeptide:O-GalNAc transferase, and, if desired, a gene encoding a mucin-type glycopeptide; and producing a mucin-type glycoprotein having O-GalNAc by use of the yeast.

Abstract: This invention provides proteins and genes thereof involved in the GPI lipid remodeling process and, thereby and constructing a system for screening for useful substances such as anticancer agents and a system for detecting abnormalities in the GPI lipid remodeling process.

Abstract: A protein having (a) an amino acid sequence represented by SEQ ID NO: 2, SEQ ID NO: 4, SEQ ID NO: 20, SEQ ID NO: 6 or SEQ ID NO: 8, or (b) an amino acid sequence represented by SEQ ID NO: 2, SEQ ID NO: 4, SEQ ID NO: 20, SEQ ID NO: 6 or SEQ ID NO: 8, wherein one or more amino acids are deleted, substituted and/or added in the amino acid sequence set forth in SEQ ID NO: 2, SEQ ID NO: 4, SEQ ID NO: 20, SEQ ID NO: 6 or SEQ ID NO: 8, and said sequence has a UDP-glucose 4,6-dehydratase activity, and/or UDP-4-keto-6-deoxyglucose 3,5-epimerase and UDP-4-keto-rhamnose 4-keto-reductase activities; and a method of producing UDP-rhamnose using the above-described protein.

Abstract: A method for breeding yeast having thermotolerance or recovering growth activity and a method for breeding yeast which produces beta-glucan efficiently as well as an yeast obtained by such methods for breeding are presented by a method for breeding yeast having thermotolerance or recovering growth activity including a step for controlling proofreading function of DNA polymerase in a loss-of-function mutant of yeast (for example, a step for including mutant pol3 gene or mutant cdc6?gene in a gene-disruptant.

Abstract: The present invention relates to an enzyme having novel N-acetylglucosaminyltransferase (OMGnT) activity, a polynucleotide encoding the enzyme, a recombinant polynucleotide comprising the polynucleotide, a host cell comprising the recombinant polynucleotide, a method for producing an enzyme protein having OMGnT activity by culturing the host cell in a medium, and a method for modifying a sugar chain structure with the enzyme and a carbohydrate having a sugar chain structure modified by the method. This enzyme enables the production of complex carbohydrates, which could not be formed with conventional glycosyltransferases.

Abstract: The present invention relates to a gene for an enzyme involving in the synthesis of GDP-L-fucose. Particularly, the present invention relates to a GDP-4-keto-6-deoxy-D-mannose-3, 5-epimerase-4-reductase gene derived from Arabidopsis thaliana, and a process for producing GDP-L-fucose using the gene. An enzyme encoded by the gene is (a) a protein comprising an amino acid sequence represented by SEQ ID NO: 1; or (b) a protein comprising an amino acid sequence derived from the amino acid sequence of SEQ ID NO: 1 by deletion, substitution, addition or insertion of one or several amino acid residues, and having GDP-4-keto-6-deoxy-D-mannose-3, 5-epimerase-4-reductase activity. The present invention enables efficient mass production of GDP-L-fucose which is essential in performing addition of fucose, which has a very important function in sugar chains.

Abstract: The present invention enables screening for compounds that inhibit the transport of GPI-anchored proteins to fungal cell walls, using a simple assay for transacylation to GlcN-PI using membrane fraction expressing GWT1 protein. New antifungal agents can be created that inhibit the synthesis of fungal cell walls and also inhibit adhesion to host cells by inhibiting the transport of GPI-anchored proteins to fungal cell walls.

Abstract: This invention is to provide a process for producing a glycoprotein comprising a mammalian type sugar chain, characterized in that the process comprises introducing an ?-1,2-mannosidase gene into a methylotrophic yeast having a mutation of a sugar chain biosynthesizing enzyme gene, so that the ?-1,2-mannosidase gene is expressed under the control of a potent promoter in the yeast; culturing in a medium the methylotrophic yeast cells with a heterologous gene transferred thereinto; and obtaining the glycoprotein comprising a mammalian type sugar chain from the culture. Using the newly created methylotrophic yeast having a sugar chain mutation, a neutral sugar chain identical with a high mannose type sugar chain produced by mammalian cells such as human cells, or a glycoprotein comprising such a neutral sugar chain, can be produced in a large amount at a high purity.

Abstract: An object of the present invention is to provide a means for producing O-fucosylated protein in large quantities, a means for searching for new genes associated with the synthesis system of O-fucosylated protein or the proteins expressed by the genes, and a means for elucidating the functions thereof. According to the present invention, a yeast transformant characterized in that the genes associated with the synthesis system of O-fucosylated protein are a GDP-fucose synthase gene, a GDP-fucose transporter gene, a fucosyltransferase gene, and a fucose receptor gene is provided.

Abstract: A process for producing a lysosomal enzyme having a mannose-6-phosphate-containing acidic sugar chain, wherein the process comprising: culturing in a medium yeast cells obtained by introducing a lysosomal enzyme gene into a sugar chain biosynthetic enzyme gene mutant strain of yeast, collecting a lysosomal enzyme having a phosphate-containing sugar chain from the culture, and then treating the enzyme with ?-mannosidase; and pharmaceutical compositions for treatment of human lysosomal enzyme deficiencies produced by the process. The genetic engineering technique using the yeast according to the present invention allows large-amount and high-purity production of a glycoprotein having a phosphate-containing acidic sugar chain which can serve as a labeling marker for transporting into lysosomes in cells of mammals such as human. The glycoprotein having a phosphate-containing acidic sugar chain according to the invention may be utilized as a drug effective in treatment of human lysosomal enzyme deficiencies, etc.

Abstract: The present invention relates to an enzyme having novel N-acetylglucosaminyltransferase (OMGnT) activity, a polynucleotide encoding the enzyme, a recombinant polynucleotide comprising the polynucleotide, a host cell comprising the recombinant polynucleotide, a method for producing an enzyme protein having OMGnT activity by culturing the host cell in a medium, and a method for modifying a sugar chain structure with the enzyme and a carbohydrate having a sugar chain structure modified by the method. This enzyme enables the production of complex carbohydrates, which could not be formed with conventional glycosyltransferases.