摘要 |
Disclosed herein are fully impaired consensus Kozak sequences which are most typically used with dominant selectable markers of transcriptional cassettes which are a part of an expression vector. These vectors are most typically utilized in the expression of proteins in mammalian expression systems. As defined, disclosed and claimed herein, a "fully impaired consensus Kozak" comprises the following sequence: <IMAGE> where: Nat nucleotides 2,3,8 and 9 is a nucleotide selected from the group consisting of adenme (A), quanine (G), cytosine (C) or thymine (T)/uracil (U); Nat nucleotides 1 and 7 is a pyrimidine nucleotide, ie C or T/U; "ATG" is a codon encoding for the amino acid methionine, the so-called "start" codon; and -3 and +1 are directional reference points vis-a-vis ATG, ie -3 is meant to indicate three nucleotides upstream of ATG and +1 is meant to indicate one nucleotide downstream of ATG. Dominant selectable markers further comprising artificial intronic insertion regions are further disclosed. |