A truncated Ah receptor blocks the hypoxia and estrogen receptor signaling pathways: a viable approach for breast cancer treatment.

The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor which requires heterodimerization with the Ah receptor nuclear translocator (Arnt) for function. Arnt is also a dimerization partner of the hypoxia inducible factor 1alpha (HIF-1alpha) for the hypoxia signaling. Additionally, Arnt is found to be a potent coactivator of the estrogen receptor (ER) signaling.

Synthesis of 32P-labelled protein probes using a modified thioredoxin fusion protein expression system in Escherichia coli.

The thioredoxin fusion protein expression system from invitrogen was modified so that 32P-labelled recombinant proteins can be easily obtained in large quantities for functional studies. Proteins that are prone to form the inclusion bodies can be functionally expressed as thioredoxin fusion proteins in Escherichia coli. After expression, the recombinant proteins can be easily phosphorylated with 32P-gamma ATP and the 32P-labelled protein can be obtained functionally via a mild proteolytic digestion to cleave off the thioredoxin moiety.