Protein secretion in eukaryotic cells

Abstract

The invention relates to the use of a glucosidase II mutation to increase protein secretion in yeast cells. The invention relates further to the use of yeast cells, comprising a mutant glucosidase II gene, possibly in combination with the expression of a recombinant α-1,2-mannosidase gene and/or a recombinant N-acetylglucosaminyl-transferase gene, as a host for protein secretion.

1 . An improvement in a method for secreting exogenous protein from a yeast cell, the improvement comprising:
 utilizing a glucosidase II mutation to increase protein secretion from the yeast cell.   
     
     
         2 . The method according to  claim 1 , wherein said glucosidase II mutation is an inactivating knock out mutation. 
     
     
         3 . The method according to  claim 1 , wherein said glucosidase II mutation is a point mutation. 
     
     
         4 . The method according to  claim 1 , wherein said glucosidase II mutation affects only one subunit of glucosidase II enzyme. 
     
     
         5 . The method according to  claim 4 , wherein said glucosidase II mutation affects subunit alpha. 
     
     
         6 . A host for protein secretion, said host comprising:
 a yeast comprising a recombinant defective glucosidase II.   
     
     
         7 . An improvement in a method of the type involving using yeast to secrete protein, the improvement comprising:
 utilizing, in the method, a yeast having a defective glucosidase II as host for protein secretion.   
     
     
         8 . The method according to  claim 7  wherein said defective glucosidase II is a recombinant glucosidase II. 
     
     
         9 . The method according to  claim 7 , wherein the yeast is selected from the group consisting of  Kluyveromyces  sp.,  Pichia  sp.,  Hansenula  sp. or  Schizzosaccharomyces pombe.    
     
     
         10 . The method according to  claim 7 , wherein the yeast is a  Saccharomyces  sp. 
     
     
         11 . The method according to  claim 7 , wherein said glucosidase is defective in subunit alpha. 
     
     
         12 . The method according to  claim 8 , wherein said glucosidase is defective in subunit alpha. 
     
     
         13 . The method according to  claim 9 , wherein said glucosidase is defective in subunit alpha. 
     
     
         14 . The method according to  claim 10 , wherein said glucosidase is defective in subunit alpha. 
     
     
         15 . The method according to  claim 8 , wherein the yeast is selected from the group consisting of  Kluyveromyces  sp.,  Pichia  sp.,  Hansenula  sp. or  Schizzosaccharomyces pombe.    
     
     
         16 . The method according to  claim 8 , wherein the yeast is a  Saccharomyces  sp. 
     
     
         17 . The method according to  claim 15 , wherein the glucosidase is defective in subunit alpha. 
     
     
         18 . The method according to  claim 16 , wherein the glucosidase is defective in subunit alpha. 
     
     
         19 . The method according to  claim 2 , wherein the glucosidase II mutation affects only one subunit of glucosidase II enzyme. 
     
     
         20 . The method according to  claim 3  wherein the glucosidase II mutation affects only one subunit of glucosidase II enzyme.