Novel interactions of the GABPα transcription factor complex

Abstract

GA-binding protein α, (GABPα), also referred to NRF-2 or E4TF-1 in humans, is a transcription factor found on Chromosome 21 that forms part of the ETS (E-TwentySix) transcription factor family. It is the only member of this family that forms an obligate heteromeric protein complex due to the lack of a transactivation domain. It forms heterodimers or tetramers with GABPβ and can also recruit other co-factors. This allows GABP to cover a multitude of roles in transcription control. In this study, a search for novel GABPα interactors was carried out using a Y east-Two Hybrid Assay. From the proteins isolated, five were chosen for further analyses: GABP γ, FHL2, NELF-E, TXN and Hypothetical Protein LOC124512 (EBM). Their interaction with GABPα was then tested for physical binding by co-IP and functionally analysed by luciferase assay. Of these five proteins, GABPγ,, FHL2, NELF-E, TXN and EBM showed a functional response but only GABPγ,, FHL2 and EBM were isolated by co-IP. Mechanisms are being proposed for each functional interaction in an attempt to offer a window into possible GABPα implicated pathogenesis. Key words: GABPα, protein interactions, FHL2, NELF-E, TXN, Hypothetical Protein LOC124512