Transcription factors and their use

A transcription factor with a DNA-binding domain comprising a basic domain and an adjacent Leucine zipper domain with the following amino acids:

• L el x gl x x x L e2 x g2 x x x′ x L e3 x g3 x x x L e4 x g4 x x x L e5
• wherein L is leucine, gi and ei are possible substitution locations, x are any amino acids, and x′ is one of tyrosin and glycin and wherein one of the following sets of substituents are at the nine substitution locations ei and gi:
• 2 KK KQ AT RQ K SEQ ID NO 3 EE EQ AT RQ K SEQ ID NO 4 EK KQ AT EE K SEQ ID NO 5 EE EQ AT EE K SEQ ID NO 6 KK EQ AT RQ K SEQ ID NO 7 KE EQ AT RQ K SEQ ID NO 8 KK KQ AT EE K SEQ ID NO 9 KE EQ AT EE K SEQ ID NO 10 EK KQ AT RQ E SEQ ID NO 11 KK KQ AT RQ E SEQ ID NO 12 EK EQ AT RQ E SEQ ID NO 13 EE EQ AT RQ E SEQ ID NO 14 EK KQ AT EE E SEQ ID NO 15 EE EQ AT EE E SEQ ID NO 16 KK SL QE RE K SEQ ID NO 18 EK SR QV RE K SEQ ID NO 19 KK SR QV RE K SEQ ID NO 20,
• valin being replaceable by alanine, leucine, methionine, isoleucine, glutamine.