Difference between revisions of "Part:BBa J176013"

Revision as of 02:33, 22 November 2011

VP64

Tetrameric VP16 transcription activator domain

Usage and Biology

• Chassis: mammalian cells
• Mammalian expression vector required
• Protein domain; requires promoter, start codon, stop codon, and polyA signal for proper expression
• VP64 doesn't do much as a free-floating domain. Fuse it to a DNA binding domain
  

VP64 is a transcriptional activator composed of four tandem copies of VP16 (Herpes Simplex Viral Protein 16, amino acids 437-447, DALDDFDLDML) connected with glycine-serine linkers. When fused to another protein domain that can bind near the promoter of a gene, VP64 acts as a strong transcriptional activator.

Characterization

VP64 activity is sensitive to promoter proximity.
In our hands, VP64 activity is maximized when it is targeted to DNA sequences that are ~40-80 base pairs away from a minimal promoter. When fused to the Gal4 DNA binding domain (BBa_J176020) and targeted it to Gal (UAS) DNA elements (BBa_J176019) that are assembled immediately adjacent to the HSVtkTATA minimal promoter (BBa_J176011), we observe weak activation, and perhaps repression, of a fluorescent reporter gene. In contrast, when a small spacer (BBa_J176039) is inserted between the Gal4 binding sites and the promoter, reporter gene activity greatly increases.

(Data will be posted soon)

Sequence and Features