What is claimed is:
1. A mutant mammalian cell having a homozygous disruption in the RNase L gene thereof and in the PKR gene thereof, wherein said mutant mammalian cell lacks biologically active RNase L enzyme and biologically active PKR enzyme.
2. The mutant cell of claim 1 wherein said cell is a mouse cell.
3. A method for producing high levels of an exogenous, recombinant protein comprising:
a) providing a mutant mammalian cell having a homozygous disruption in its RNase L gene, or its PKR gene, or both, wherein said mutant mammalian cell lacks biologically active RNase L enzyme, or biologically active PKR enzyme, or both:
b) introducing a first nucleic acid encoding the exogenous protein into the mutant mammalian cell;
c) expressing said exogenous protein in said cell; and
d) isolating said exogenous protein from said cell.
4. The method of claim 3 wherein said mutant mammalian cell has a homozygous disruption in its RNase L gene and in its PKR gene, further comprising:
introducing a second nucleic acid encoding adenovirus VAI RNA or VA II RNA into said cell, and co-expressing said exogenous protein and said adenovirus RNA.
5. The method of claim 3, wherein said mutant mammalian cell has a homozygous disruption in its RNase L gene, further comprising:
introducing a second nucleic acid encoding adenovirus VAI RNA or adenovirus VA II RNA into said cell, and co-expressing said exogenous protein and said adenovirus RNA.
6. The method of claim 3, wherein said mutant mammalian cell has a homozygous disruption in its RNase L gene, further comprising:
introducing a second nucleic acid encoding a dominant negative PKR polypeptide into said cell, and co-expressing said exogenous protein and said dominant negative PKR polypeptide.
7. The method of claim 6 further comprising introducing a third nucleic acid encoding adenovirus VAI RNA or adenovirus VA II RNA into said cell, and co-expressing said exogenous protein, said dominant negative PKR polypeptide, and said adenovirus RNA.
8. The method of claim 3, wherein said cell has a homozygous disruption in its PKR gene and lacks biologically active PKR enzyme.
9. The method of claim 8, further comprising: introducing a second nucleic acid encoding adenovirus VAI RNA or adenovirus VA II RNA into said cell, and co-expressing said exogenous protein and said adenovirus RNA
10. The method of claim 8 further comprising: introducing a second nucleic acid encoding a dominant negative RNase L polypeptide into said cell, and co-expressing said exogenous protein and said dominant negative RNase L polypeptide.
11. The method of claim 10 further comprising:
introducing a third nucleic acid encoding adenovirus VAI RNA or adenovirus VA II RNA into said cell, and co-expressing said exogenous protein, said dominant negative RNase L polypeptide, and said adenovirus RNA
12. A method for enhancing production of an exogenous, recombinant protein in a mammalian cell having an RNase L; PKR genotype comprising:
a) introducing a first nucleic acid encoding the exogenous protein into said mammalian cell;
b) introducing a second nucleic acid encoding a dominant negative RNase L polypeptide or a dominant defective PKR polypeptide into said cell
c) co-expressing said exogenous protein and said dominant negative polypeptide in said cell; and
d) isolating said exogenous protein from said cell.
13. The method of claim 12 wherein said second nucleic acid encodes a dominant negative RNase L polypeptide.
14. The method of claim 12 wherein said second nucleic acid encodes a dominant negative PKR polypeptide.
15. The method of claim 13 further comprising:
introducing a third nucleic acid encoding adenovirus VA 1 RNA or Va II RNA into said cell and co-expressing said exogenous protein, said dominant negative RNase L polypeptide, and said adenovirus RNA in said cell.
16. The method of claim 14 further comprising
introducing a third nucleic acid encoding adenovirus VA 1 RNA or VA II RNA into said cell and co-expressing said exogenous protein, said dominant negative PKR polypeptide, and said adenovirus RNA in said cell.
17. The method of claim 13 further comprising:
introducing a third nucleic acid encoding a dominant negative PKR polypeptide and co-expressing said exogenous protein, said dominant negative RNase L polypeptide, and said dominant defective PKR polypeptide in said cell.
18. The method of claim 17 further comprising:
introducing a fourth nucleic acid encoding adenovirus VA I RNA or VA II RNA in said cell; and co-expressing said exogenous protein, said dominant negative RNase L polypeptide, said dominant negative PKR polypeptide, and said adenovirus RNA in said cell.
19. A method for preparing mutant non-human mammalian cells for producing high levels of recombinant proteins, comprising:
a) intercrossing a first non-human mammal with a second non-human mammal of the same species, said first non-human mammal having a heterozygous disruption in its RNase L gene and said second non-human mammal having a heterozygous disruption in its PKR gene;
b) characterizing the embryos produced by step (a) to identify an embryo having an RNase L: PKR genotype; and
c) isolating somatic cells from the embryo having said RNase L: PKR genotype.
20. The method of claim 20 wherein said mammal is a mouse and wherein said somatic cells are fibroblasts.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. Conductor insertion plug (1) having a grip section (2) and at least one conductive plug section (3) for insertion into a conductor insertion opening (25) in a spring force terminal (20) which has an insulating material housing (21) with at least one busbar (22) inserted therein and at least one clamping spring (23), with the clamping spring (23) having a clamping edge (24) which is oriented at an acute angle in relation to an electrical conductor which is inserted into the conductor insertion opening (25) and, together with an opposite section of the busbar (22), forms a clamping point for the electrical conductor, characterized in that
the plug section (3) which is located outside the grip section (2) is formed, at least in a contact region which is intended to make contact with the clamping spring (23), with at least two layers comprising a first layer (4) which faces the clamping spring (23) and is composed of a first metal material and a second layer (5) which faces the busbar (22) and is composed of a second metal material.
2. Conductor insertion plug according to claim 1, characterized in that the first layer (4) of the plug section (3), which layer faces the clamping spring (23), consists of a steel alloy which is harder than or at least approximately as hard as the clamping spring (23).
3. Conductor insertion plug according to claim 1, characterized in that the second layer (5) of the plug section (3), which layer faces the busbar (22), consists of a material which has a higher electrical conductivity than the material of the first layer (4).
4. Conductor insertion plug according to claim 3, characterized in that the electrically conductive material of the second layer (5) is copper or a copper alloy.
5. Conductor insertion plug according to claim 3, characterized in that the material of the second layer (5) has a surface coating.
6. Conductor insertion plug according to claim 5, characterized in that the surface of the second layer (5) is coated with tin or a tin alloy.
7. Conductor insertion plug according to claim 1, characterized in that the at least first layer (4) and the at least second layer (5) are firmly connected to one another by means of a cohesive connection or an adhesive bond or an interlocking connection.
8. Conductor insertion plug according to claim 1, characterized in that the plug section (3) is substantially linear andor has a substantially rectangular cross section over its section which can be inserted into the spring force terminal (20).
9. Conductor insertion plug according to claim 1, characterized in that the grip section (2) of the conductor insertion plug (1) has a coding device for an insertion process in the correct position.
10. Conductor insertion plug according to claim 9, characterized in that the grip section (2) of the conductor insertion plug (1) has a coding lug (6) which extends in the direction of the plug section (3) and adjacent to the plug section (3) and which is adapted in order to enter an operating opening which is arranged next to the conductor insertion opening (25) in the insulating material housing (21) of the spring force terminal (20).
11. Conductor insertion plug according to claim 1, characterized in that the conductor insertion plug (1) is in the form of a bridge with at least two plug sections which are arranged next to one another and extend in parallel in the same direction and are electrically conductively connected to one another.
12. Conductor insertion plug according to claim 1, characterized in that the conductor insertion plug (1) is in the form of a test plug with a test connection which is electrically conductively connected to the plug section (3) andor with a conductor connection apparatus which is electrically conductively connected to the plug section (3) for connection of an electrical conductor (15).
13. Conductor insertion plug according to claim 2, characterized in that the second layer (5) of the plug section (3), which layer faces the busbar (22), consists of a material which has a higher electrical conductivity than the material of the first layer (4).
14. Conductor insertion plug according to claim 4, characterized in that the material of the second layer (5) has a surface coating.