Modulation of the Zac1's transactivation and coactivation functions via PML and Daxx within distinct subcellular localizations.
Zac1 acts as a transcription factor and a transcriptional cofactor cooperated with histone acetyltransferases and/or histone deacetylases. The molecular mechanisms underlying the subcellular localization and specificity of Zac1 transcriptional regulation are unclear. Here, we show that Zac1 might have physical and functional interactions with death-associated protein (Daxx) and promyelocytic leukemia protein (PML). However, unlike Daxx, nuclear Zac1 was not relocalized into PML nuclear bodies (PML-NBs). The enhancement of the transactivation activity of Zac1 by PML and Daxx might occur outside PML-NBs. Other components of PML-NBs, such as CREB-binding protein (CBP), ubiquitin-conjugating enzyme 9, and p53, were also regulatory targets for Zac1, for whom the locations to mediate its regulatory functions were distinct from PML-NBs. Our findings further suggest that Zac1 might play differential roles over the functions of CBP depending on the status of post-translational modification on CBP. Hence, our results link PML-NB components to the transactivation and coactivation functions of Zac1 at non-PML-NB sites.
Ho
Ching-Liang
CL
Department of Medicine, Division of Hematology/Oncology, Tri-Service General Hospital, National Defense Medical Center, Taipei, 114, Taiwan, ROC. 02241@ndmctsgh.edu.tw
Huang
Yu-Chi
YC
Tai
Chien-Kuo
CK
Liu
Shu-Ting
ST
Wang
Jehng-Kang
JK
Wang
Wei-Ming
WM
Huang
Shih-Ming
SM
D021581:Active Transport, Cell Nucleus; D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism*; D050882:CREB-Binding Protein / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism*; D003001:Cloning, Molecular; D056970:Co-Repressor Proteins; D005455:Fluorescent Antibody Technique; D006367:HeLa Cells; D006801:Humans; D045586:Intranuclear Inclusion Bodies / Q000378:metabolism*; D018832:Molecular Chaperones; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D000071156:Promyelocytic Leukemia Protein; D011485:Protein Binding; D021381:Protein Transport; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D015533:Transcriptional Activation; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism; D025521:Tumor Suppressor Proteins / Q000235:genetics / Q000378:metabolism*; D044763:Ubiquitin-Conjugating Enzymes / Q000378:metabolism
D048868:Adaptor Proteins, Signal Transducing; D018797:Cell Cycle Proteins; D056970:Co-Repressor Proteins; C106985:DAXX protein, human; D018832:Molecular Chaperones; D009687:Nuclear Proteins; C106464:PLAGL1 protein, human; D000071156:Promyelocytic Leukemia Protein; D014157:Transcription Factors; D016159:Tumor Suppressor Protein p53; D025521:Tumor Suppressor Proteins; C070576:PML protein, human; D050882:CREB-Binding Protein; D044763:Ubiquitin-Conjugating Enzymes