Modification of GATA-2 transcriptional activity in endothelial cells by the SUMO E3 ligase PIASy.
GATA sequences are required for the optimal expression of endothelial cell-specific genes, including endothelin-1 (ET-1). We have identified PIASy in a search for new GATA-2 interacting proteins that can regulate GATA-2-mediated endothelial gene expression. Notably, among the cell populations comprising vascular walls, PIASy mRNA is selectively expressed in endothelial cells, and its expression can be regulated by angiogenic growth factors. We show that GATA-2 is covalently modified by small ubiquitin-like modifier (SUMO)-1 and -2 and that PIASy, through its E3 SUMO ligase activity, preferentially enhances the conjugation of SUMO-2 to GATA-2. Through a functional analysis, we demonstrate that PIASy potently suppresses the activity of the GATA-2-dependent human ET-1 promoter in endothelial cells. The suppressive effect of PIASy requires the GATA-binding site in the ET-1 promoter and depends on its interaction with GATA-2, which requires both N-terminal (amino acids 1-183) and C-terminal (amino acids 414-510) sequences in PIASy. We conclude that PIASy enhances the conjugation of SUMO-2 to GATA-2 and that the interaction of PIASy with GATA-2 can modulate GATA-mediated ET-1 transcription activity in endothelial cells through a RING-like domain-independent mechanism.
Department of Medicine and Clinical Science, University Graduate School of Medicine, Kyoto, Japan. taehwa@umich.edu
Tae-Hwa
TH
Chun
Hiroshi
H
Itoh
Lalitha
L
Subramanian
Jorge A
JA
Iñiguez-Lluhí
Kazuwa
K
Nakao
D000818:Animals; D001665:Binding Sites; D019556:COS Cells; D002352:Carrier Proteins / Q000235:genetics / Q000502:physiology*; D002460:Cell Line; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D019332:Endothelin-1 / Q000235:genetics*; D004730:Endothelium, Vascular / Q000201:enzymology / Q000378:metabolism*; D050989:GATA2 Transcription Factor; D020868:Gene Silencing; D006367:HeLa Cells; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D008025:Ligases / Q000235:genetics / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D000075223:Poly-ADP-Ribose Binding Proteins; D011401:Promoter Regions, Genetic; D050828:Protein Inhibitors of Activated STAT; D012333:RNA, Messenger / Q000096:biosynthesis; D025841:Small Ubiquitin-Related Modifier Proteins / Q000378:metabolism*; D014157:Transcription Factors / Q000037:antagonists & inhibitors* / Q000378:metabolism; D015533:Transcriptional Activation; D044767:Ubiquitin-Protein Ligases
D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D019332:Endothelin-1; D050989:GATA2 Transcription Factor; C494711:GATA2 protein, human; C494712:Gata2 protein, mouse; D047908:Intracellular Signaling Peptides and Proteins; C485891:PIAS4 protein, human; D000075223:Poly-ADP-Ribose Binding Proteins; D050828:Protein Inhibitors of Activated STAT; D012333:RNA, Messenger; D025841:Small Ubiquitin-Related Modifier Proteins; D014157:Transcription Factors; D044767:Ubiquitin-Protein Ligases; D008025:Ligases