PC4 (Positive Cofactor 4 wild type) Transcriptional Coactivator

The human PC4 is a non-TAF transcription coactivator that mediates activator-dependent transcription by RNA polymerase II in vitro through most tested activators. The function of PC4 is apparently through interactions with transcriptional activators and the basal transcription machinery. It is negatively regulated by casein kinase II phosphorylation both in vitro and in vivo (1-3). PC4 strongly binds single stranded DNA and regulates HSSB (RPA)-dependent SV40 DNA replication (4, 5). Recent studies indicated that PC4 can be acetylated by several histone acetyltransferases (6).
Recombinant PC4 protein (wild type, 127 amino acids) is isolated from an E. coli strain that carries the coding sequence of human PC4 under the control of T7 promoter and purified by conventional chromatography.
Recombinant PC4 has been utilized for in vitro function studies, including transcription, DNA replication, in vitro phosphorylation, gel mobility shift assay, protein-protein interactions and as a substrate for in vitro acetylation.
Protein is greater than 95% homogeneous and contains no detectable protease, DNase and RNase activity.
1 unit equals 1 nanogram of purified protein. 1 unit is sufficient for a gel mobility shift assay in a 20µl reaction; 20 units are sufficient for reconstituted transcription assay and 100 units are sufficient for a protein-protein interaction assay.
variable in different lots
1x dilution buffer A: 20 mM Tris-Cl (pH 8.0), 20% Glycerol, 100 mM KCl, 1 mM DTT and 0.2 mM EDTA
 
References:
1. Ge, H. et al., (1994) Cell 78, 513-523; (1994) Proc. Natl. Acad. Sci. USA 91, 12691-12695
2. Kretzschmar, M. et al., (1994) Cell 78, 525-534
3. Ge, H. et al., (1996) Methods Enzymol. 274, 57-71
4. Ballard, DW. et al., (1988) J. Biol. Chem. 263, 8450-8457
5. Pan, ZQ. et al., (1996) J. Biol. Chem. 271, 22111-22116
6. Kumar, BR. et al., (2001) J. Biol. Chem. 276, 16804-1689