Abstract: To provide a method for producing transferrin by secretion with high productivity using a transformant of Schizosaccharomyces pombe, and a transformant suitable for the method. A transformant using Schizosaccharomyces pombe as a host, comprising a transferrin gene and a secretion signal peptide gene expressing transferrin to which a secretion signal peptide which functions in the host binds, located in an upstream region of the transferrin gene, and having gas2 gene endogenous to the host deleted or inactivated; and a method for producing transferrin, which comprises culturing the transformant in a liquid medium and obtaining transferrin from the liquid medium.

Abstract: To provide a method for producing transferrin by secretion with high productivity using a transformant of Schizosaccharomyces pombe, and a transformant suitable for the method. A transformant using Schizosaccharomyces pombe as a host, comprising a transferrin gene and a secretion signal peptide gene expressing transferrin to which a secretion signal peptide which functions in the host binds, located in an upstream region of the transferrin gene, and having gas2 gene endogenous to the host deleted or inactivated; and a method for producing transferrin, which comprises culturing the transformant in a liquid medium and obtaining transferrin from the liquid medium.

Abstract: In a method of constructing a eukaryotic host microorganism for production of a heterologous protein encoded by a trangenically introduced gene, production efficiency of the heterologous protein by the transformant obtained by introducing the gene encoding the heterologous protein into the host is improved. Part or all of the genome unnecessary or detrimental to production of the heterologous protein by the transformant in culture is deleted or inactivated. The eukaryotic host microorganism is preferably Schizosaccharomyces pombe. The part of the genome of the eukaryotic host microorganism to be deleted or inactivated is preferably a gene selected from the genes associated with energy metabolism and the genes associated with proteases, such as a pyruvate decarboxylase gene, a serine protease gene, an aminopeptidase gene and a carboxypeptidase gene.

Abstract: In a method of constructing a eukaryotic host microorganism for production of a heterologous protein encoded by a trangenically introduced gene, production efficiency of the heterologous protein by the transformant obtained by introducing the gene encoding the heterologous protein into the host is improved.

Abstract: An isolated DNA in an invertase gene from Schizosaccharomyces pombe, which is located in a region involved in catabolite repression. The DNA may be incorporated into cloning vector, particularly a vector containing a heterologous protein structural gene. The vector can be used to transform Schizosaccharomyces pombe. A heterologous protein may be produced by incubating the transformant and isolating the protein.

Abstract: A secretion signal gene having a base sequence encoding a polypeptide functional as a secretion signal in fission yeast Schizosaccharomyces pombe (hereinafter referred to as S. pombe), an expression vector having the gene and a foreign protein structural gene, a multicloning vector for construction of the expression vector which has the secretion signal gene, and efficient secretory production of the foreign protein structural gene product by S. pombe and the like.

Abstract: The present invention relates to an expression vector capable of being expressed in a fission yeast Schizosaccharomyces pombe, a multicloning vector for construction of the expression vector, a method of constructing the expression vector, a transformant carrying the expression vector, and a method of producing a foreign protein using the transformant. The multicloning vector has a sequence of -ACATGT-from the 5' direction, as a restriction enzyme recognition site for introduction of a structural gene of a foreign protein at the front end of its multicloning site. To construct the expression vector, the structural gene of the foreign protein is introduced by using the restriction enzyme recognition site so that the front end of the introduced structural gene of the foreign protein has a sequence of -ACATGN- (wherein N is an arbitrary base) from the 5' direction, and ATG in the sequence functions as the translation initiation site for the structural gene of the foreign protein.

Abstract: The present invention is a peptide having from 5 to 20 amino acid residues having tumor cell invasion-inhibiting activities. As such a peptide, a peptide represented by any one of the formulas (1) to (13) is preferred among peptides.Further, the present invention is a cancer metastasis inhibitor comprising the above peptide as an active ingredient.Furthermore, the present invention is a peptide complex having a peptide having tumor cell invasion-inhibiting activities and a polymer derived from a vital body chemically bonded to each other. As such a peptide, a peptide represented by any one of the formulas (1) to (14) is preferred among peptides. As the polymer derived from a vital body, a protein such as albumin or globulin is preferred.Still further, the present invention is a cancer metastasis inhibitor comprising the above peptide complex as an active ingredient.