Activation function 2 domain

Cho S, Blackford JA Jr, Simons SS Jr. Role of activation function domain 1, DNA binding, and coactivator in the expression of partial agonist activity of glucocorticoid receptor complexes. Biochemistry 2005 44 3547-3561. 

PNRC Two proline-rich nuclear receptor coregulatory proteins (PNRC1 and PNRC2) were cloned from a mammary gland cDNA library (97,98). These proteins are relatively small, with molecular weights of 16 kDa and 35 kDa, respectively. Both PNRCs interacted with hormone receptors in a ligand-dependent manner, mediated by an activation function domain that contains an NR box-like... 

The methods involved in the production of proteins in microbes are those of gene expression. Several plasmids for expression of proteins having affinity tails at the C- or N-terminus of the protein have been developed. These tails are usefiil in the isolation of recombinant proteins. Most of these vectors are commercially available along with the reagents that are necessary for protein purification. A majority of recombinant proteins that have been attempted have been produced in E. Coli (1). In most cases these recombinant proteins formed aggregates resulting in the formation of inclusion bodies. These inclusion bodies must be denatured and refolded to obtain active protein, and the affinity tails are usefiil in the purification of the protein. Some of the methods described herein involve identification of functional domains in proteins (see also Protein engineering). 

SHRs are built in a modular structure with similar structure elements. They contain a DNA-binding domain (DBD), a hinge region with a nuclear location signal (NLS), a ligand-binding domain (LBD) and several transcriptional activation functions (Fig. 1). 

Fig. 3.17 Activation of gene transcription by artificial transcription factors. (Top) The artificial activator is composed of three separate functional domains. The DNA binding domain consists of the pyrrole/imidazole polyamides (shown as connected arrows). A tethered linker domain (shown as a coil) connects the DNA binding domain to the peptide activation domain (AD, shown as an oval).

Chen, G., Wang, L., Liu, S., Chuang, C. and Roche, T.E. (1996) Activated function of the pyruvate dehydrogenase phosphatase through Ca2+-facilitated binding to the inner lipoyl domain of the dihydrolipoyl acetyltransferase. Journal of Biological Chemistry 271,28064-28070. 

Gomez, E., and Pavitt, G. D. (2000). Identification of domains and residues within the epsilon subunit of eukaryotic translation initiation factor 2B (eIF2Bepsilon) required for guanine nucleotide exchange reveals a novel activation function promoted by eIF2B complex formation. Mol. Cell Biol. 20, 3965—3976. 

Despite the data reviewed here, the work is not finished at all. Physicochemical data have to be correlated with biological activity and the complexity of the living cell has to be reflected in the biophysical setups. This covers the use of full-length proteins instead of only functional domains, processed proteins instead of the straightforward bacterial expression, and the introduction of a membranous environment vs simple experiments in solution. 

All fungal prion proteins have a so-called prion domain and a functional domain. The prion domain is a region of the polypeptide chain that is necessary and sufficient for prion formation and maintenance (Fig. 1 Wickner et al., 2002). For Ure2p and Sup35p, the functional domain is responsible for the cellular activity of the normal form of the protein. 

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