Structural and mechanistic insights into cooperative assembly of dimeric Notch transcription complexes.
Ligand-induced proteolysis of Notch produces an intracellular effector domain that transduces essential signals by regulating the transcription of target genes. This function relies on the formation of transcriptional activation complexes that include intracellular Notch, a Mastermind co-activator and the transcription factor CSL bound to cognate DNA. These complexes form higher-order assemblies on paired, head-to-head CSL recognition sites. Here we report the X-ray structure of a dimeric human Notch1 transcription complex loaded on the paired site from the human HES1 promoter. The small interface between the Notch ankyrin domains could accommodate DNA bending and untwisting to allow a range of spacer lengths between the two sites. Cooperative dimerization occurred on the human and mouse Hes5 promoters at a sequence that diverged from the CSL-binding consensus at one of the sites. These studies reveal how promoter organizational features control cooperativity and, thus, the responsiveness of different promoters to Notch signaling.
Arnett
Kelly L
KL
Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA.
Hass
Matthew
M
McArthur
Debbie G
DG
Ilagan
Ma Xenia G
MX
Aster
Jon C
JC
Kopan
Raphael
R
Blacklow
Stephen C
SC
D000818:Animals; D001483:Base Sequence; D051792:Basic Helix-Loop-Helix Proteins / Q000737:chemistry / Q000378:metabolism; D001665:Binding Sites; D017124:Conserved Sequence; D018360:Crystallography, X-Ray; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism; D019281:Dimerization; D018398:Homeodomain Proteins / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D051819:Immunoglobulin J Recombination Signal Sequence-Binding Protein / Q000737:chemistry / Q000378:metabolism; D051379:Mice; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D017434:Protein Structure, Tertiary; D051881:Receptor, Notch1 / Q000737:chemistry* / Q000378:metabolism; D012097:Repressor Proteins / Q000737:chemistry; D000072056:Transcription Factor HES-1; D014157:Transcription Factors / Q000737:chemistry / Q000378:metabolism
D051792:Basic Helix-Loop-Helix Proteins; D004268:DNA-Binding Proteins; D018398:Homeodomain Proteins; D051819:Immunoglobulin J Recombination Signal Sequence-Binding Protein; D051881:Receptor, Notch1; D012097:Repressor Proteins; D000072056:Transcription Factor HES-1; D014157:Transcription Factors; C430872:MAML1 protein, human; C497761:NOTCH1 protein, human; C497570:RBPJ protein, human; C077478:HES5 protein, human; C078493:HES1 protein, human