CCAAT/Enhancer-binding protein beta DNA binding is auto-inhibited by multiple elements that also mediate association with p300/CREB-binding protein (CBP).
Signaling through Ras GTPases controls the activity of many transcription factors including CCAAT/enhancer-binding protein (C/EBPbeta), which regulates oncogenic H-Ras(V12)-induced senescence and growth arrest. Here we report that C/EBPbeta (LAP) DNA binding is inhibited by N-terminal sequences and derepressed by oncogenic Ras signaling. Sequence and mutational analyses showed that auto-repression involves two LXXLF (phiXXphiphi)-like motifs (LX1 and LX2) and a third element, auto-inhibitory domain (AID), located within conserved region CR5. LX1 is a critical component of the transactivation domain and has been shown to mediate C/EBPbeta binding to the TAZ2 region of p300/CREB-binding protein coactivators. C/EBPbeta auto-repression also involves a C-terminal regulatory domain (CRD) adjacent to the leucine zipper. CRD contains a third phiXXphiphi motif (LX3) and a short sequence, KQL, which has similarity to a region in the protein-binding site of TAZ2. The C/EBPbeta N- and C-terminal domains physically associate in a manner that requires the basic region and CRD. We propose a model in which the regulatory sequences form a hydrophobic core that reciprocally inhibits DNA binding and transactivation. We also suggest a mechanism for C/EBPbeta derepression involving several recently identified modifications within AID and CRD. Finally, we show that association of activated C/EBPbeta with p300/CREB-binding protein requires the LX2 and AID auto-inhibitory elements. Thus, the N-terminal regulatory elements have dual roles in auto-inhibition and coactivator binding.
Lee
Sook
S
Laboratory of Cancer Prevention, NCI-Frederick, National Institutes of Health, Frederick, Maryland 21702-1201, USA.
Miller
Maria
M
Shuman
Jon D
JD
Johnson
Peter F
PF
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D022782:CCAAT-Enhancer-Binding Protein-beta / Q000378:metabolism*; D004247:DNA / Q000737:chemistry*; D004742:Enhancer Elements, Genetic; D006801:Humans; D008969:Molecular Sequence Data; D011485:Protein Binding; D011499:Protein Processing, Post-Translational; D017434:Protein Structure, Tertiary; D051381:Rats; D015398:Signal Transduction; D014158:Transcription, Genetic; D050880:p300-CBP Transcription Factors / Q000378:metabolism*
D022782:CCAAT-Enhancer-Binding Protein-beta; D004247:DNA; D050880:p300-CBP Transcription Factors
Mol Cell Biol. 1997 Apr;17(4):2038-47
9121452
Proc Natl Acad Sci U S A. 2002 Jan 8;99(1):207-12
11756662
Structure. 2009 Feb 13;17(2):202-10
19217391
Genes Dev. 1994 Apr 15;8(8):869-84
7523245
Science. 1982 Jul 23;217(4557):316-24
6283634
Mol Endocrinol. 2007 Oct;21(10):2311-9
17536004
Annu Rev Biochem. 2008;77:557-82
18410249
Genes Dev. 1991 Sep;5(9):1553-67
1884998
J Biol Chem. 1995 Jun 23;270(25):15130-6
7797496
Mol Cell Biol. 1997 Nov;17(11):6609-17
9343424
Cell. 2002 Jan 11;108(1):57-70
11792321
EMBO J. 1993 Apr;12(4):1321-32
8467792
J Biol Chem. 2000 May 26;275(21):15912-6
10821850
Mol Cell Biol. 2010 Jun;30(11):2621-35
20351173
EMBO J. 1995 Sep 1;14(17):4318-28
7556073
J Biol Chem. 2001 Jan 5;276(1):505-13
11018027
Biochem J. 2002 Aug 1;365(Pt 3):561-75
12006103
Proc Natl Acad Sci U S A. 1993 Mar 15;90(6):2207-11
8384717
Cell Cycle. 2006 May;5(9):953-7
16687924
Mol Cell Biol. 1996 May;16(5):2065-73
8628272
J Biol Chem. 2002 Oct 11;277(41):38827-37
12177065
Nature. 1993 Oct 28;365(6449):855-9
8413673
J Biol Chem. 2002 Oct 11;277(41):38037-44
12161447
Cell Mol Life Sci. 2000 Aug;57(8-9):1172-83
11028910
EMBO J. 1997 Mar 17;16(6):1371-80
9135152
J Biol Chem. 2000 May 26;275(21):16373-81
10748205
Genes Dev. 1998 Nov 1;12(21):3343-56
9808622
Mol Cell Biol. 2003 Mar;23(6):2135-50
12612084
EMBO J. 1995 Jul 3;14(13):3170-83
7621830
Biochemistry. 2009 Feb 17;48(6):1244-55
19166313
Science. 1990 Aug 17;249(4970):771-4
2202050
Cell. 2008 Jun 13;133(6):1019-31
18555778
Protein Eng. 2001 Dec;14(12):993-1000
11809930
J Biol Chem. 2003 Apr 25;278(17):15178-84
12578822
Cell. 2007 Jul 27;130(2):223-33
17662938
Nat Rev Cancer. 2003 Nov;3(11):859-68
14668816
Genes Dev. 1993 May;7(5):749-59
7684005
Mol Cell Biol. 2004 Apr;24(8):3238-50
15060147
Expert Rev Mol Med. 2009 Apr 08;11:e12
19351437
Genes Dev. 1994 Nov 15;8(22):2781-91
7958933
FEBS Lett. 1987 Nov 16;224(1):149-55
3678489
Mol Immunol. 2007 Feb;44(6):1384-92
16784777
EMBO J. 2005 Sep 21;24(18):3301-12
16107878
Mol Cell Biol. 2004 Sep;24(17):7380-91
15314150
EMBO J. 1993 May;12(5):2027-38
8491193
EMBO J. 2009 Apr 8;28(7):948-58
19214187
Methods Enzymol. 1996;266:525-39
8743704
Cell Mol Life Sci. 1997 Aug;53(8):621-45
9351466
Cold Spring Harb Symp Quant Biol. 1998;63:621-9
10384327
Cold Spring Harb Symp Quant Biol. 1998;63:587-98
10384324
Bioinformatics. 2005 May 1;21(9):1891-900
15657106
Nucleic Acids Res. 2004 Jul 1;32(Web Server issue):W321-6
15215403
J Mol Biol. 2000 Apr 14;297(5):1183-94
10764582
J Biol Chem. 2003 Sep 19;278(38):36959-65
12857754