ZNF652

ZNF652 is a nuclear C2H2 zinc finger transcription factor that recognizes a defined DNA element in target gene promoters and acts predominantly as a sequence-specific transcriptional repressor through assembly of corepressor complexes (PMID:18456661, PMID:21678463). Its repressive activity is mediated by direct physical interaction with the ETO-family corepressor CBFA2T3, an association formed through the C-terminal ~109 residues of ZNF652 and a conserved proline-rich region that engages the NHR3/NHR4 domains of CBFA2T3, enabling repression of E-box target genes such as HEB (PMID:16966434, PMID:18456661). ZNF652 also associates with the NuRD corepressor complex to silence a cohort of genes including PD-L1, and loss of ZNF652 derepresses PD-L1 to drive immune evasion in triple-negative breast cancer (PMID:37906592). Through direct promoter binding it represses the cyclin D3 (CCND3) gene to enforce G1 cell-cycle arrest in lung cancer, a phenotype rescued by ectopic cyclin D3 (PMID:39500884). In other tumor contexts ZNF652 instead acts as an activator, transcriptionally inducing circRHOT1 and recruiting the histone acetyltransferase KAT5 to deposit H3K27ac at the SLC38A6 promoter (PMID:41311269), indicating context-dependent repressor or activator activity. A paralogous protein, ZNF651, shares the ZNF652 DNA-binding consensus and forms an analogous CBFA2T3 corepressor complex (PMID:20116376).

1. 2006 Medium

   Establishing ZNF652 as a transcriptional repressor required identifying a binding partner and a functional output; the discovery that it interacts with the ETO-family repressor CBFA2T3 and represses reporter transcription defined its core molecular role.

   Evidence Yeast two-hybrid screen, reciprocal Co-IP with C-terminal deletion mapping, and transcriptional reporter assays

   PMID:16966434

   Open questions at the time

   • No endogenous target gene identified at this stage
   • DNA-binding specificity of ZNF652 not yet defined
2. 2008 High

   To connect ZNF652 to genuine gene regulation, its DNA consensus and a bona fide endogenous target were needed; ZNF652-CBFA2T3 was shown to bind a single response element in the HEB promoter and repress it, with the interaction interface mapped to a proline-rich C-terminal region engaging CBFA2T3 NHR3/NHR4.

   Evidence ChIP, in vitro DNA-binding assays with consensus identification, reporter assays, and Co-IP with domain mutagenesis

   PMID:18456661

   Open questions at the time

   • Genome-wide target repertoire not yet defined
   • Whether other corepressors participate not addressed
3. 2010 Medium

   The question of whether ZNF652 repression is paralog-redundant was addressed by showing ZNF651 shares the same DNA consensus and also forms a CBFA2T3 corepressor complex, indicating potentially tissue-specific functional overlap.

   Evidence DNA-binding assays, Co-IP, and reporter assays comparing ZNF651 and ZNF652

   PMID:20116376

   Open questions at the time

   • Tissue-specific division of labor between paralogs not demonstrated in vivo
   • Distinct target genes for each paralog not resolved
4. 2011 Medium

   Defining the breadth of ZNF652 regulation required genome-scale mapping; ChIP-chip identified a refined recognition motif and promoter targets across diverse pathways including cancer progression.

   Evidence Genome-wide ChIP-chip in breast cancer cells with de novo motif scanning

   PMID:21678463

   Open questions at the time

   • Functional consequences of most identified binding sites not validated
   • Activator vs repressor outcome per target not resolved
5. 2023 High

   Beyond CBFA2T3, ZNF652 was shown to act through the NuRD complex to repress PD-L1, establishing a mechanistic link between ZNF652 loss and tumor immune evasion in triple-negative breast cancer.

   Evidence Reciprocal Co-IP for NuRD association, ChIP, and overexpression/knockdown with functional immune-evasion readouts in vitro and in vivo

   PMID:37906592

   Open questions at the time

   • Which NuRD subunit directly contacts ZNF652 not defined
   • Relationship between NuRD- and CBFA2T3-dependent repression not reconciled
6. 2024 Medium

   A direct cell-cycle role was established by showing ZNF652 binds the CCND3 promoter and represses it to enforce G1 arrest, with ectopic cyclin D3 rescuing the phenotype.

   Evidence ChIP, promoter reporter assays, RNA-seq, and CCND3 rescue with cell-cycle analysis in lung cancer cells

   PMID:39500884

   Open questions at the time

   • Corepressor complex used at the CCND3 promoter not identified
   • Whether this repression depends on CBFA2T3 or NuRD untested
7. 2025 Medium

   ZNF652 was shown to function as an activator in hepatocellular carcinoma, recruiting the acetyltransferase KAT5 to deposit H3K27ac and activate SLC38A6, and inducing circRHOT1, expanding its role beyond repression.

   Evidence ChIP, promoter binding and histone-modification assays, and silencing/overexpression with rescue experiments in HCC cells

   PMID:41311269

   Open questions at the time

   • Determinants that switch ZNF652 between activator and repressor modes unknown
   • Direct ZNF652-KAT5 physical interaction not established

• What dictates the context-dependent choice between corepressor assembly (CBFA2T3/NuRD) and coactivator recruitment (KAT5/H3K27ac), and the conflicting reports of PD-L1 repression versus activation, remain unresolved.
• No mechanism reconciling repressor vs activator activity at the same target (PD-L1)
• No structural model of ZNF652 DNA or partner interfaces
• Post-translational or cofactor switches governing complex choice unidentified