Requirement of the coiled-coil domain of PML-RARalpha oncoprotein for localization, sumoylation, and inhibition of monocyte differentiation.
Homo-oligomerization via a coiled-coil (C-C) domain has been shown to be necessary for the promyelocytic leukemia (PML)-retinoic acid receptor-alpha (RARalpha) fusion protein to acquire oncogenic potential in acute promyelocytic leukemia. We show here that PML(DeltaC-C)-RARalpha, which contains a deletion in its C-C domain, is neither localized as characteristic microspeckles nor modified by small ubiquitin-like modifiers (SUMO). The absence of sumoylation of the DeltaC-C mutant was due to the lack of binding to Ubc9, a SUMO conjugation enzyme. The integrity of RING finger domain was also needed for both sumoylation and microspeckle formation. In GAL4-DNA tethering assays, the DeltaC-C mutant completely lost the inhibitory effect on retinoic acid (RA)-mediated transactivation. Furthermore, the expression of CD14 in U937 cells expressing the DeltaC-C mutant in response to vitamin D3 was markedly higher than in cells expressing PML-RARalpha. However, the RA-mediated induction of C/EBPbeta in cells expressing the DeltaC-C mutant was comparable to that of control cells. Thus, our results suggest that the C-C domain-associated functions of sumoylation, localization as microspeckles, and the inhibition of monocyte differentiation all contribute to the oncogenic activity of PML-RARalpha.
Kim
Young-Eui
YE
Department of Molecular Cell Biology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon, Kyonggido 440-746, Republic of Korea.
Kim
Dong-Yeon
DY
Lee
Jang-Mi
JM
Kim
Seong-Tae
ST
Han
Tae-Hee
TH
Ahn
Jin-Hyun
JH
D021581:Active Transport, Cell Nucleus / Q000187:drug effects; D000818:Animals; D022782:CCAAT-Enhancer-Binding Protein-beta / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D009000:Monocytes / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D009154:Mutation / Q000235:genetics; D009363:Neoplasm Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D015514:Oncogene Proteins, Fusion / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary; D025842:SUMO-1 Protein / Q000378:metabolism*; D014212:Tretinoin / Q000494:pharmacology; D044763:Ubiquitin-Conjugating Enzymes / Q000378:metabolism; D000098843:Ubiquitin-Conjugating Enzyme UBC9
D022782:CCAAT-Enhancer-Binding Protein-beta; D009363:Neoplasm Proteins; D015514:Oncogene Proteins, Fusion; D025842:SUMO-1 Protein; C093476:promyelocytic leukemia-retinoic acid receptor alpha fusion oncoprotein; D014212:Tretinoin; D044763:Ubiquitin-Conjugating Enzymes; D000098843:Ubiquitin-Conjugating Enzyme UBC9