p27Kip1, PCAF and PAX5 cooperate in the transcriptional regulation of specific target genes

Abstract

The cyclin-dependent kinase inhibitor p27Kip1 (p27) also behaves as a transcriptional repressor. Data showing that the p300/CBP-associated factor (PCAF) acetylates p27 inducing its degradation suggested that PCAF and p27 could collaborate in the regulation of transcription. However, this possibility remained to be explored. We analyzed here the transcriptional programs regulated by PCAF and p27 in the colon cancer cell line HCT116 by chromatin immunoprecipitation sequencing (ChIP-seq). We identified 269 protein-encoding genes that contain both p27 and PCAF binding sites being the majority of these sites different for PCAF and p27. PCAF or p27 knock down revealed that both regulate the expression of these genes, PCAF as an activator and p27 as a repressor. The double knock down of PCAF and p27 strongly reduced their expression indicating that the activating role of PCAF overrides the repressive effect of p27. We also observed that the transcription factor Pax5 interacts with both p27 and PCAF and that the knock down of Pax5 induces the expression of p27/PCAF target genes indicating that it also participates in the transcriptional regulation mediated by p27/PCAF. In summary, we report here a previously unknown mechanism of transcriptional regulation mediated by p27, Pax5 and PCAF.

Sublytic C5b-9 Induces IL-23 and IL-36a Production by Glomerular Mesangial Cells via PCAF-Mediated KLF4 Acetylation in Rat Thy-1 Nephritis

“…A feature of KLF4 is pleiotropy, as confirmed by its ability to either activate or repress transcription, depending on the cell context (27,54). Rosenzweig et al (25) have pointed out that a possible explanation is that KLF4 can recruit different transcriptional cofactors (35). Our study revealed that PCAF, as a transcriptional coactivator, could interact with KLF4, forming a complex, and bind to specific region of IL-23 or IL-36a promoter in a KLF4-dependent manner.…”

“…It is well accepted that cytokine gene transcription is regulated by protein translational modification (e.g., acetylation) (32,33). Previous data have proved that PCAF acts as a histone acetyltransferase (HAT) and can acetylate histones and nonhistone proteins (34)(35)(36), affecting target gene transcription (31)(32)(33)(34)(35). Song et al (36) have reported that PCAF can interact with KLF2 through specific domains, resulting in KLF2 acetylation, and PCAF can acetylate KLF13 to regulate KLF13 binding to target DNA (37).…”

The CDK inhibitor p57Kip2 enhances the activity of the transcriptional coactivator FHL2

“…Some phenotypes of p57-deficient mice were even enhanced when a cyclin/CDK binding deficient mutant (p57 CK− ) was expressed in mice, indicating additional dominant effects of the p57 CK− mutant by so far unknown mechanisms 8 . Several recent publications highlighted a role of the closely related p27 protein as a transcription regulator which can be CDK-dependent and CDK-independent [10][11][12][13] . p57 has also been reported to directly and indirectly regulate transcription; it binds and inactivates CDK7 and CDK9 and interacts with the transcription factor E2F1 thereby repressing E2F1 regulated genes 14 .…”

Microenvironment-Derived FGF-2 Stimulates Renal Cell Carcinoma Cell Proliferation through Modulation of p27^Kip1: Implications for Spatial Niche Formation and Functional Intratumoral Heterogeneity

“…The quantitative PCR was performed with the SsoFast TM EvaGreen ® supermix (Bio-Rad) under the following conditions: 30 s activation at 95 ° C, 5 s denaturation at 95 ° C and 5 s annealing/extension at 60 ° C for GAPDH for 40 cycles on a Bio-Rad CFX96 Real-Time System run on a C1000 Thermal Cycler Platform (Bio-Rad). Primers for p27 Kip1 were adapted from Perearnau et al [7] (forward 5-ATGTCAAA-CGTGCGAGTGTC-3; reverse 5-TCTCTGCAGTGCTTCTCC-AA-3; obtained from IDT, Leuven, Belgium). GAPDH cDNA served as reference for relative quantification.…”