Methods and cells for expression of recombinant protein products under the transcriptional control of an inducible promoter

Abstract

The present invention relates generally to improved methods for the expression of recombinant protein products under the transcriptional control of an inducible promoter, such as an araB promoter, in bacterial host cells that are deficient in one or more of the active transport systems for the inducer of the inducible promoter. The present invention also relates to improved bacterial host cells that are deficient in one or more of the active transport systems for an inducer of an inducible promoter, such as arabinose for an araB promoter, and contain an expression vector encoding a recombinant polypeptide under the transcriptional control of the inducible promoter, such as an araB promoter.

1 . A method for producing a recombinant protein product under the control of an inducible promoter comprising: (a) introducing an expression vector encoding a recombinant protein product under the control of an inducible promoter into a bacterial host cell that is genetically deficient in at least one system for active transport of an inducer of the promoter into the host cell; and (b) inducing expression of the product with the inducer.  
   
   
       2 . The method of  claim 1 , wherein the inducible promoter is an araB promoter.  
   
   
       3 . The method of  claim 2 , wherein the inducer is arabinose.  
   
   
       4 - 5 . (canceled)  
   
   
       6 . The method of  claim 1 , wherein the host cell is deficient in the low affinity arabinose transport system encoded by the araE gene.  
   
   
       7 . The method of  claim 1 , wherein the host cell is deficient in the high affinity arabinose transport system encoded by the araFGH genes.  
   
   
       8 . The method of  claim 1 , wherein the host cell is deficient in both the high affinity arabinose transport system encoded by the araFGH genes and the low affinity arabinose transport system encoded by the araE gene.  
   
   
       9 . (canceled)  
   
   
       10 . A bacterial host cell that is deficient in one or more of the active transport systems for an inducer of an inducible promoter, wherein the host cell contains a recombinant expression vector encoding a recombinant protein product under the control of the inducible promoter.  
   
   
       11 . The host cell of  claim 10 , wherein the inducible promoter is an araB promoter.  
   
   
       12 . The host cell of  claim 11 , where the inducer is arabinose.  
   
   
       13 - 14 . (canceled)  
   
   
       15 . The host cell of  claim 10 , wherein the host cell is deficient in the low affinity arabinose transport system encoded by the araE gene.  
   
   
       16 . The host cell of  claim 10 , wherein the host cell is deficient in the high affinity arabinose transport system encoded by the araFGH genes.  
   
   
       17 . The host cell of  claim 10 , wherein the host cell is deficient in both the high affinity arabinose transport system encoded by the araFGH genes and the low affinity arabinose transport system encoded by the araE gene.  
   
   
       18 - 42 . (canceled)  
   
   
       43 . A method for producing a recombinant protein product under the control of an inducible promoter comprising: (a) culturing a bacterial host cell that is genetically deficient in at least one system for active transport of an inducer of an inducible promoter into the host cell, wherein the host cell contains an expression vector encoding a recombinant protein product under the control of the promoter; and (b) inducing expression of the product with the inducer.  
   
   
       44 . The method of  claim 43 , wherein the inducible promoter is an araB promoter.  
   
   
       45 . The method of  claim 44 , wherein the inducer is arabinose.  
   
   
       46 - 47 . (canceled)  
   
   
       48 . The method of  claim 43 , wherein the host cell is deficient in the low affinity arabinose transport system encoded by the araE gene.  
   
   
       49 . The method of  claim 43 , wherein the host cell is deficient in the high affinity arabinose transport system encoded by the araFGH genes.  
   
   
       50 . The method of  claim 43 , wherein the host cell is deficient in both the high affinity arabinose transport system encoded by the araFGH genes and the low affinity arabinose transport system encoded by the araE gene.  
   
   
       51 . (canceled)