JunD represses transcription and translation of the tight junction protein zona occludens-1 modulating intestinal epithelial barrier function.
The AP-1 transcription factor JunD is highly expressed in intestinal epithelial cells, but its exact role in maintaining the integrity of intestinal epithelial barrier remains unknown. The tight junction (TJ) protein zonula occludens (ZO)-1 links the intracellular domain of TJ-transmembrane proteins occludin, claudins, and junctional adhesion molecules to many cytoplasmic proteins and the actin cytoskeleton and is crucial for assembly of the TJ complex. Here, we show that JunD negatively regulates expression of ZO-1 and is implicated in the regulation of intestinal epithelial barrier function. Increased JunD levels by ectopic overexpression of the junD gene or by depleting cellular polyamines repressed ZO-1 expression and increased epithelial paracellular permeability. JunD regulated ZO-1 expression at the levels of transcription and translation. Transcriptional repression of ZO-1 by JunD was mediated through cAMP response element-binding protein-binding site within its proximal region of the ZO-1-promoter, whereas induced JunD inhibited ZO-1 mRNA translation by enhancing the interaction of the ZO-1 3'-untranslated region with RNA-binding protein T cell-restricted intracellular antigen 1-related protein. These results indicate that JunD is a biological suppressor of ZO-1 expression in intestinal epithelial cells and plays a critical role in maintaining epithelial barrier function.
Chen
Jie
J
Department of Surgery, University of Maryland School of Medicine, Baltimore, MD, USA.
Xiao
Lan
L
Rao
Jaladanki N
JN
Zou
Tongtong
T
Liu
Lan
L
Bellavance
Emily
E
Gorospe
Myriam
M
Wang
Jian-Ying
JY
D001665:Binding Sites; D045744:Cell Line, Tumor; D003110:Colonic Neoplasms / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism; D004847:Epithelial Cells / Q000378:metabolism; D004848:Epithelium / Q000378:metabolism*; D017353:Gene Deletion; D006801:Humans; D008565:Membrane Proteins / Q000378:metabolism / Q000502:physiology*; D010750:Phosphoproteins / Q000378:metabolism / Q000502:physiology*; D011073:Polyamines / Q000378:metabolism; D011485:Protein Binding; D014176:Protein Biosynthesis; D019108:Tight Junctions; D018808:Transcription Factor AP-1 / Q000378:metabolism*; D014158:Transcription, Genetic; D062826:Zonula Occludens-1 Protein
D008565:Membrane Proteins; D010750:Phosphoproteins; D011073:Polyamines; C569042:TJP1 protein, human; D018808:Transcription Factor AP-1; D062826:Zonula Occludens-1 Protein; D000242:Cyclic AMP