TRIP-Br: a Novel Family of PHD Zinc Finger- and Bromodomain-interacting Proteins That Regulate the Transcriptional Activity of E2F-1/DP-1
Overview
Molecular Biology
Affiliations
We report the isolation of TRIP-Br1, a transcriptional regulator that interacts with the PHD-bromodomain of co-repressors of Krüppel-associated box (KRAB)-mediated repression, KRIP-1(TIF1beta) and TIF1alpha, as well as the co-activator/adaptor p300/CBP. TRIP-Br1 and the related protein TRIP-Br2 possess transactivation domains. Like MDM2, which has a homologous transactivation domain, TRIP-Br proteins functionally contact DP-1, stimulating E2F-1/DP-1 transcriptional activity. KRIP-1 potentiates TRIP-Br protein co-activation of E2F-1/DP-1. TRIP-Br1 is a component of a multiprotein complex containing E2F-1 and DP-1. Co-expression of the retinoblastoma gene product (RB) abolishes baseline E2F-1/DP-1 transcriptional activity as well as TRIP-Br/KRIP-1 co-activation, both of which are restored by the adenovirus E1A oncoprotein. These features suggest that TRIP-Br proteins function at E2F-responsive promoters to integrate signals provided by PHD- and/or bromodomain- containing transcription factors. TRIP-Br1 is identical to the cyclin-dependent kinase 4 (cdk4)-binding protein p34(SEI-1), which renders the activity of cyclin D/cdk4 resistant to the inhibitory effect of p16(INK4a) during late G(1). TRIP-Br1(p34(SEI-1)) is differentially overexpressed during the G(1) and S phases of the cell cycle, consistent with a dual role for TRIP-Br1(p34(SEI-1)) in the regulation of cell cycle progression through sequential effects on the transcriptional activity of E2F-responsive promoters during G(1) and S phases.
Akpoghiran O, Afonso D, Zhang Y, Koh K J Neurosci. 2024; 44(5).
PMID: 38296648 PMC: 10860567. DOI: 10.1523/JNEUROSCI.0922-23.2023.
Regenerative growth is constrained by brain tumor to ensure proper patterning in Drosophila.
Abidi S, Hsu F, Smith-Bolton R PLoS Genet. 2023; 19(12):e1011103.
PMID: 38127821 PMC: 10769103. DOI: 10.1371/journal.pgen.1011103.
Molecular Mechanism of PP2A/B55α Phosphatase Inhibition by IER5.
Cao R, Jones D, Pan L, Yang A, Wang S, Padi S bioRxiv. 2023; .
PMID: 37693604 PMC: 10491241. DOI: 10.1101/2023.08.29.555174.
Jung S, Myagmarjav D, Jo T, Lee S, Han S, Quynh N Int J Biol Sci. 2022; 18(9):3859-3873.
PMID: 35813469 PMC: 9254482. DOI: 10.7150/ijbs.72138.
Sequential actions of EOMES and T-BET promote stepwise maturation of natural killer cells.
Zhang J, Le Gras S, Pouxvielh K, Faure F, Fallone L, Kern N Nat Commun. 2021; 12(1):5446.
PMID: 34521844 PMC: 8440589. DOI: 10.1038/s41467-021-25758-2.