Mahboube Ganji arjenaki - Department of Genetics, Faculty of Basic Sciences,University ofShahrekord, Shahrekord, Iran
Mojtaba Emadi-bygi - Applied Physiology Research Center, Faculty of Medicine,
Parvaneh Nikpour - Research Institute of Biotechnology, University of Shahrekord, Shahrekord, Iran

Background:The zinc-finger X linked (ZFX) gene encodes a transcription factor that acts as a regulator of self-renewal of stem cells. Due to the role of ZFX in cell growth, understanding ZFX protein-protein interactions helps to clarify its proper biological functions in signaling pathways. The aim of this study is to define ZFX protein-protein interactions and the role of ZFX in cell growth. Materials and Methods: The PIPs output includes three interacting proteins with ZFX: eukaryotic translation initiation factor ۳ subunit I(EIF۳I), eukaryotic translation initiation factor ۳ subunit G(EIF۳G) and protein nuclear pore and COPII coat complex component homolog isoform ۳ (SEC۱۳L۱). Results: As a cargo and transmembrane protein interacting with Sec۱۳,eIF۳I and eIF۳G, ZFX mediates cargo sorting in COPII vesicles at ER exit sites. While traveling to cis-Golgi, eIF۳I is phosphorylated by the mechanistic target of rapamycin (mTOR). Proteins transport by COPI vesicles to the nucleusouter site layer containing SEC۱۳ via the contribution of microtubules. EIF۳G and eIF۳I interact with coatomer protein complex subunit beta ۲ (COPB۲) that helps to enclose ZFX in COPI vesicle. ZFX and eIF۳G enter nucleolus where activation of transcription from pre rDNA genes occurs. Conclusion:We proposed a model in which ZFX is involved in cell growth by promoting the transcription of rDNA genes.

ZFX, Cell growth, Cancer stem cells, rDNA genes, Protein-protein interactions