Shared and discrete interacting partners of ELL1 and ELL2 by yeast two-hybrid assay

Copyright © 2013 Fortuna Arumemi et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. ELL2 (eleven-nineteen lysine-rich leukemia tran-scription elongation factor), a component of a larger complex with pTEFb (cyclin T and CDK9) and AF4, is up-regulated in plasma cells where it influences mRNA processing by increasing exon skipping and enhancing proximal poly (A) site use. ELL2 is needed to produce the secretory-specific Ig heavy chain mRNA while ELL1 mRNA does not change in abun-dance with B cell stages. To investigate the potential interactions of other proteins with the ELL1 and ELL2 proteins, we preformed yeast two-hybrid stud-ies. HSP40 and Testin were found to bind to ELL2 in its amino-terminal half. PCNA binds to ELL2 in a region encompassing amino acids 186- 344. The po-tent transcription factors HIF1 α and ZNF622 inter-act with both ELL1 and 2 in the central, proline rich region. Meanwhile, BBS2 and ING3 interact with ELL1 but not ELL2 in this central proline-rich re-gion. Many of the ELL-interacting-proteins uncov-ered in the two-hybrid screen are tumour suppressors that may work through the ELL: pTEFb complex to suppress or activate sets of genes in plasma cells