N-terminal transcriptional activation domain of LZIP comprises two LxxLL motifs and the host cell factor-1 binding motif.
Host Cell Factor-1 (HCF-1, C1) was first identified as a cellular target for the herpes simplex virus transcriptional activator VP16. Association between HCF and VP16 leads to the assembly of a multiprotein enhancer complex that stimulates viral immediate-early gene transcription. HCF-1 is expressed in all cells and is required for progression through G(1) phase of the cell cycle. In addition to VP16, HCF-1 associates with a cellular bZIP protein known as LZIP (or Luman). Both LZIP and VP16 contain a four-amino acid HCF-binding motif, recognized by the N-terminal beta-propeller domain of HCF-1. Herein, we show that the N-terminal 92 amino acids of LZIP contain a potent transcriptional activation domain composed of three elements: the HCF-binding motif and two LxxLL motifs. LxxLL motifs are found in a number of transcriptional coactivators and mediate protein-protein interactions, notably recognition of the nuclear hormone receptors. LZIP is an example of a sequence-specific DNA-binding protein that uses LxxLL motifs within its activation domain to stimulate transcription. The LxxLL motifs are not required for association with the HCF-1 beta-propeller and instead interact with other regions in HCF-1 or recruit additional cofactors.
Luciano
R L
RL
Department of Microbiology and Kaplan Comprehensive Cancer Center, New York University School of Medicine, New York, NY 10016, USA.
Wilson
A C
AC
D000595:Amino Acid Sequence; D001665:Binding Sites; D002460:Cell Line; D017362:Cyclic AMP Response Element-Binding Protein; D015967:Gene Expression Regulation, Viral; D017405:Herpes Simplex Virus Protein Vmw65 / Q000235:genetics* / Q000378:metabolism; D051863:Host Cell Factor C1; D006801:Humans; D016350:Leucine Zippers; D008969:Molecular Sequence Data; D011485:Protein Binding; D011506:Proteins / Q000235:genetics* / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D015533:Transcriptional Activation
C107941:CREB3 protein, human; D017362:Cyclic AMP Response Element-Binding Protein; C497692:HCFC1 protein, human; D017405:Herpes Simplex Virus Protein Vmw65; D051863:Host Cell Factor C1; D011506:Proteins; D014157:Transcription Factors