The Impact of Lens Epithelium-Derived Growth Factor p75 Dimerization on Its Tethering Function.
Cells
; 13(3)2024 Jan 25.
Article
em En
| MEDLINE
| ID: mdl-38334618
ABSTRACT
The transcriptional co-activator lens epithelium-derived growth factor/p75 (LEDGF/p75) plays an important role in the biology of the cell and in several human diseases, including MLL-rearranged acute leukemia, autoimmunity, and HIV-1 infection. In both health and disease, LEDGF/p75 functions as a chromatin tether that interacts with proteins such as MLL1 and HIV-1 integrase via its integrase-binding domain (IBD) and with chromatin through its N-terminal PWWP domain. Recently, dimerization of LEDGF/p75 was shown, mediated by a network of electrostatic contacts between amino acids from the IBD and the C-terminal α6-helix. Here, we investigated the functional impact of LEDGF/p75 variants on the dimerization using biochemical and cellular interaction assays. The data demonstrate that the C-terminal α6-helix folds back in cis on the IBD of monomeric LEDGF/p75. We discovered that the presence of DNA stimulates LEDGF/p75 dimerization. LEDGF/p75 dimerization enhances binding to MLL1 but not to HIV-1 integrase, a finding that was observed in vitro and validated in cell culture. Whereas HIV-1 replication was not dependent on LEDGF/p75 dimerization, colony formation of MLLr-dependent human leukemic THP-1 cells was. In conclusion, our data indicate that intricate changes in the quaternary structure of LEDGF/p75 modulate its tethering function.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Cromatina
/
Peptídeos e Proteínas de Sinalização Intercelular
Limite:
Humans
Idioma:
En
Revista:
Cells
Ano de publicação:
2024
Tipo de documento:
Article
País de afiliação:
Bélgica