Protein kinase A potentiates adrenal 4 binding protein/steroidogenic factor 1 transactivation by reintegrating the subcellular dynamic interactions of the nuclear receptor with its cofactors, general control nonderepressed-5/transformation/transcription domain-associated protein, and suppressor, dosage-sensitive sex reversal-1: a laser confocal imaging study in living KGN cells.
The mechanism through which protein kinase A (PKA) potentiates the transactivation ability of adrenal 4 binding protein/steroidogenic factor 1 (Ad4BP/SF-1) is currently unclear. In the present study, we investigated the mechanism by applying laser confocal microscopy and fluorescence recovery after photobleaching technique. In KGN cells, forskolin (a PKA stimulator) could reorganize wild-type Ad4BP/SF-1, but not mutant Ad4BP/SF-1 (G35E), from a diffuse distribution pattern to foci formation in the nucleus. The subcellular distributions of GCN5 (general control nonderepressed) and TRRAP (transformation/transcription domain-associated protein), both of which were recently proved to be working in the same complex as the third class of nuclear receptor coactivators, were unexpectedly diffuse inside and outside the nucleus, respectively, when they were separately transfected. However TRRAP was translocated into the nucleus in the presence of GCN5, and together with GCN5 colocalized with Ad4BP/SF-1 in the same foci when PKA was activated. A luciferase assay also indicated that these two cofactors enhanced Ad4BP/SF-1 transactivation.Dosage-sensitive sex reversal (DAX-1) interacts with and thus inhibits Ad4BP/SF-1 transactivation. The coexistence of the two proteins dramatically altered their respective subnuclear distributions. They colocalized extensively, suggestive of binding, and Ad4BP/SF-1 was sharply immobilized when DAX-1 was coexpressed, whereas PKA could maintain mobility, as evidenced by Fluorescence Recovery After Photobleaching showing that Ad4BP/SF-1 mobility recovered after forskolin treatment.Therefore, the PKA signal pathway may modify the interaction between Ad4BP/SF-1 and its activators and repressor (GCN5 and TRRAP are integrated, whereas DAX-1 is disassociated), and thus stimulate the Ad4BP/SF-1 transactivation.
Fan
WuQiang
W
Department of Medicine and Bioregulatory Science, Graduate School of Medical Science, Kyushu University, Maidashi 3-1-1, Higashi-ku, Fukuoka 812-8582, Japan.
Yanase
Toshihiko
T
Wu
Yin
Y
Kawate
Hisaya
H
Saitoh
Masayuki
M
Oba
Koichi
K
Nomura
Masatoshi
M
Okabe
Taijiro
T
Goto
Kiminobu
K
Yanagisawa
Junn
J
Kato
Shigeaki
S
Takayanagi
Ryoichi
R
Nawata
Hajime
H
D048868:Adaptor Proteins, Signal Transducing; D019943:Amino Acid Substitution; D018797:Cell Cycle Proteins; D002460:Cell Line; D045744:Cell Line, Tumor; D003001:Cloning, Molecular; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D057137:DAX-1 Orphan Nuclear Receptor; D004268:DNA-Binding Proteins / Q000235:genetics*; D005260:Female; D051717:Fushi Tarazu Transcription Factors; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics; D015723:Gene Library; D017930:Genes, Reporter; D051548:Histone Acetyltransferases; D006801:Humans; D008156:Luciferases / Q000032:analysis / Q000235:genetics; D016297:Mutagenesis, Site-Directed; D009687:Nuclear Proteins / Q000235:genetics; D010051:Ovarian Neoplasms; D010957:Plasmids; D018160:Receptors, Cytoplasmic and Nuclear / Q000502:physiology; D018168:Receptors, Retinoic Acid / Q000235:genetics; D012097:Repressor Proteins / Q000235:genetics; D013154:Spleen; D015534:Trans-Activators / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics*; D015533:Transcriptional Activation / Q000235:genetics*; D014162:Transfection; D050880:p300-CBP Transcription Factors; D000099224:p300-CBP-Associated Factor
D048868:Adaptor Proteins, Signal Transducing; D018797:Cell Cycle Proteins; D017868:Cyclic AMP-Dependent Protein Kinases; D057137:DAX-1 Orphan Nuclear Receptor; D004268:DNA-Binding Proteins; D051717:Fushi Tarazu Transcription Factors; D051548:Histone Acetyltransferases; D008156:Luciferases; D009687:Nuclear Proteins; D018160:Receptors, Cytoplasmic and Nuclear; D018168:Receptors, Retinoic Acid; D012097:Repressor Proteins; D015534:Trans-Activators; D014157:Transcription Factors; D050880:p300-CBP Transcription Factors; D000099224:p300-CBP-Associated Factor; C539965:NR0B1 protein, human; C113829:transformation-transcription domain-associated protein; C501179:KAT2A protein, human