RalA interacts with ZONAB in a cell density-dependent manner and regulates its transcriptional activity.
Ral proteins are members of the Ras superfamily of small GTPases and are involved in signalling pathways for actin cytoskeleton remodelling, cell cycle control, cellular transformation and vesicle transport. To identify novel RalA effector proteins, we used the reverse Ras recruitment system and found that RalA interacts with a Y-box transcription factor, ZO-1-associated nucleic acid-binding protein (ZONAB), in a GTP-dependent manner. The amount of the RalA-ZONAB complex increases as epithelial cells become more dense and increase cell contacts. The RalA-ZONAB interaction results in a relief of transcriptional repression of a ZONAB-regulated promoter. Additionally, expression of oncogenic Ras alleviates transcriptional repression by ZONAB in a RalA-dependent manner. The data presented here implicate the RalA/ZONAB interaction in the regulation of ZONAB function.
Frankel
Paul
P
Oncogene Team, Cancer Research UK Centre for Cell and Molecular Biology, Chester Beatty Laboratories, Institute of Cancer Research, London, UK.
Aronheim
Ami
A
Kavanagh
Emma
E
Balda
Maria S
MS
Matter
Karl
K
Bunney
Tom D
TD
Marshall
Christopher J
CJ
D000818:Animals; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D004285:Dogs; D005786:Gene Expression Regulation; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic; D020798:Two-Hybrid System Techniques; D020725:ral GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*
D004268:DNA-Binding Proteins; D014157:Transcription Factors; C409302:ZONAB protein, Canis familiaris; D020725:ral GTP-Binding Proteins