| Structural highlights
Function
RBBP4_HUMAN Core histone-binding subunit that may target chromatin assembly factors, chromatin remodeling factors and histone deacetylases to their histone substrates in a manner that is regulated by nucleosomal DNA. Component of several complexes which regulate chromatin metabolism. These include the chromatin assembly factor 1 (CAF-1) complex, which is required for chromatin assembly following DNA replication and DNA repair; the core histone deacetylase (HDAC) complex, which promotes histone deacetylation and consequent transcriptional repression; the nucleosome remodeling and histone deacetylase complex (the NuRD complex), which promotes transcriptional repression by histone deacetylation and nucleosome remodeling; the PRC2/EED-EZH2 complex, which promotes repression of homeotic genes during development; and the NURF (nucleosome remodeling factor) complex.[1]
Publication Abstract from PubMed
Sal-like 4 (SALL4) is a nuclear factor central to the maintenance of stem cell pluripotency and is a key component in hepatocellular carcinoma, a malignancy with no effective treatment. In cancer cells, SALL4 associates with nucleosome remodeling deacetylase (NuRD) to silence tumor-suppressor genes, such as PTEN. Here, we determined the crystal structure of an amino-terminal peptide of SALL4(1-12) complexed to RBBp4, the chaperone subunit of NuRD, at 2.7 A, and subsequent design of a potent therapeutic SALL4 peptide (FFW) capable of antagonizing the SALL4-NURD interaction using systematic truncation and amino acid substitution studies. FFW peptide disruption of the SALL4-NuRD complex resulted in unidirectional up-regulation of transcripts, turning SALL4 from a dual transcription repressor-activator mode to singular transcription activator mode. We demonstrate that FFW has a target affinity of 23 nM, and displays significant antitumor effects, inhibiting tumor growth by 85% in xenograft mouse models. Using transcriptome and survival analysis, we discovered that the peptide inhibits the transcription-repressor function of SALL4 and causes massive up-regulation of transcripts that are beneficial to patient survival. This study supports the SALL4-NuRD complex as a drug target and FFW as a viable drug candidate, showcasing an effective strategy to accurately target oncogenes previously considered undruggable.
Targeting cancer addiction for SALL4 by shifting its transcriptome with a pharmacologic peptide.,Liu BH, Jobichen C, Chia CSB, Chan THM, Tang JP, Chung TXY, Li J, Poulsen A, Hung AW, Koh-Stenta X, Tan YS, Verma CS, Tan HK, Wu CS, Li F, Hill J, Joy J, Yang H, Chai L, Sivaraman J, Tenen DG Proc Natl Acad Sci U S A. 2018 Jul 5. pii: 1801253115. doi:, 10.1073/pnas.1801253115. PMID:29976840[2]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Zhang Q, Vo N, Goodman RH. Histone binding protein RbAp48 interacts with a complex of CREB binding protein and phosphorylated CREB. Mol Cell Biol. 2000 Jul;20(14):4970-8. PMID:10866654
- ↑ Liu BH, Jobichen C, Chia CSB, Chan THM, Tang JP, Chung TXY, Li J, Poulsen A, Hung AW, Koh-Stenta X, Tan YS, Verma CS, Tan HK, Wu CS, Li F, Hill J, Joy J, Yang H, Chai L, Sivaraman J, Tenen DG. Targeting cancer addiction for SALL4 by shifting its transcriptome with a pharmacologic peptide. Proc Natl Acad Sci U S A. 2018 Jul 5. pii: 1801253115. doi:, 10.1073/pnas.1801253115. PMID:29976840 doi:http://dx.doi.org/10.1073/pnas.1801253115
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