Promoter of Hspa5 Gene

Abstract

The present invention provides an approach to enhancing the production of a foreign protein serving as a protein-based pharmaceutical product in host cells such as cultured cells derived from a mammal. The present invention provides transformed cells having a novel Hspa5 gene promoter, and a method for secreting and producing a foreign protein at high levels using the transformed host cells.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows: 
     
         1 . A foreign gene expression unit comprising a foreign gene and a polynucleotide consisting of a polynucleotide selected from (a) to (c):
 (a) a polynucleotide consisting of the nucleotide sequence as set forth in SEQ ID NOs: 2, 3, or 4;   (b) a polynucleotide consisting of a nucleotide sequence having 95% or higher identity to the nucleotide sequence as set forth in SEQ ID NOs: 2, 3, or 4; and   (c) a polynucleotide consisting of a nucleotide sequence having 99% or higher identity to the nucleotide sequence as set forth in SEQ ID NOs: 2, 3, or 4.   
     
     
         2 . The foreign gene expression unit according to  claim 1 , wherein the polynucleotide consisting of a polynucleotide selected from (a) to (c):
 (a) a polynucleotide consisting of the nucleotide sequence as set forth in SEQ ID NO: 2;   (b) a polynucleotide consisting of a nucleotide sequence having 95% or higher identity to the nucleotide sequence as set forth in SEQ ID NO: 2; and   (c) a polynucleotide consisting of a nucleotide sequence having 99% or higher identity to the nucleotide sequence as set forth in SEQ ID NO: 2.   
     
     
         3 . The foreign gene expression unit according to  claim 1 , wherein the polynucleotide consisting of a polynucleotide selected from (a) to (c):
 (a) a polynucleotide consisting of the nucleotide sequence as set forth in SEQ ID NO: 3;   (b) a polynucleotide consisting of a nucleotide sequence having 95% or higher identity to the nucleotide sequence as set forth in SEQ ID NO: 3; and   (c) a polynucleotide consisting of a nucleotide sequence having 99% or higher identity to the nucleotide sequence as set forth in SEQ ID NO: 3.   
     
     
         4 . The foreign gene expression unit according to  claim 1 , wherein the polynucleotide consisting of a polynucleotide selected from (a) to (c):
 (a) a polynucleotide consisting of the nucleotide sequence as set forth in SEQ ID NO: 4;   (b) a polynucleotide consisting of a nucleotide sequence having 95% or higher identity to the nucleotide sequence as set forth in SEQ ID NO: 4; and   (c) a polynucleotide consisting of a nucleotide sequence having 99% or higher identity to the nucleotide sequence as set forth in SEQ ID NO: 4.   
     
     
         5 . The foreign gene expression unit according to  claim 1 , wherein the foreign gene is a gene encoding a multimeric protein. 
     
     
         6 . The foreign gene expression unit according to  claim 1 , wherein the foreign gene is a gene encoding a hetero-multimeric protein. 
     
     
         7 . The foreign gene expression unit according to  claim 1 , wherein the foreign gene is a gene encoding an antibody or an antigen-binding fragment. 
     
     
         8 . A foreign gene expression vector comprising the foreign gene expression unit according to  claim 1 . 
     
     
         9 . A transformed cell into which the foreign gene expression vector according to  claim 8  has been introduced. 
     
     
         10 . The transformed cell according to  claim 9 , wherein the cell is a cultured cell derived from a mammal. 
     
     
         11 . The transformed cell according to  claim 10 , wherein the cultured cell derived from the mammal is a COS-1 cell, a 293 cell, or a CHO cell. 
     
     
         12 . A method for producing a foreign gene-derived protein, comprising culturing the transformed cell according to  claim 9 , and obtaining the foreign gene-derived protein from the culture. 
     
     
         13 . A polynucleotide that hybridizes under stringent conditions to a polynucleotide consisting of a nucleotide sequence complementary to the nucleotide sequence as set forth in SEQ ID NOs: 2, 3, or 4, the polynucleotide having promoter activity, and wherein the stringent conditions comprise (a) a hybridization solution at 68 degrees Celsius, or (b) a DNA-immobilized filter with 0.7 to 1.0 M NaCl at 68 degrees Celsius and the hybridized polynucleotides are washed at 68 degrees Celsius with a 0.1× to 2× saline-sodium citrate (SSC) solution. 
     
     
         14 . A foreign gene expression vector comprising a polynucleotide consisting of (i) and (ii):
 (i) at least one sequence selected from (a) to (c):
 (a) a polynucleotide consisting of the nucleotide sequence as set forth in SEQ ID NOs: 2, 3, or 4; 
 (b) a polynucleotide consisting of a nucleotide sequence having 95% or higher identity to the nucleotide sequence as set forth in SEQ ID NOs: 2, 3, or 4; and 
 (c) a polynucleotide consisting of a nucleotide sequence having 99% or higher identity to the nucleotide sequence as set forth in SEQ ID NOs: 2, 3, or 4; and 
   (ii) at least one sequence selected from (a) to (e):
 (a) a polynucleotide consisting of the nucleotide sequence as set forth in SEQ ID NO: 35; 
 (b) a polynucleotide consisting of the nucleotide sequence as set forth in SEQ ID NO: 36; 
 (c) a polynucleotide consisting of the nucleotide sequence as set forth in SEQ ID NO: 37; 
 (d) a polynucleotide consisting of a nucleotide sequence having 95% or higher identity to the nucleotide sequence of any one of the polynucleotides (a) to (c), the polynucleotide having foreign gene expression-enhancing activity, and 
 (e) a polynucleotide consisting of a nucleotide sequence having 99% or higher identity to the nucleotide sequence of any one of the polynucleotides (a) to (c), the polynucleotide having foreign gene expression-enhancing activity.