ZNF335

ZNF335 (NIF-1) is a nuclear C2H2 zinc finger protein that functions as a transcriptional cotransducer and chromatin-complex scaffold controlling neural progenitor self-renewal, neurogenesis, and additional differentiation programs (PMID:23178126, PMID:12215545). It is the core scaffold of a ~1.5 MDa nuclear complex containing Ash2L, RbBP5, WDR5, HCF-1, DBC-1, and EMSY that carries histone methyltransferase activity, and it is a component of a vertebrate-specific trithorax H3K4-methylation complex that directly regulates the neural master regulator REST/NRSF and other neural-specific genes (PMID:23178126, PMID:19131338). ZNF335 acts as a cotransducer that potentiates ligand-dependent transcription by nuclear hormone receptors and other factors through the coactivator NRC, and its activity is required for the transcriptional enhancement contributed by CCR4-NOT components CNOT6/CNOT9 (PMID:12215545, PMID:18180299). It binds DNA through two distinct zinc finger clusters that each recognize a separate consensus motif, and a disease-associated R1092W mutation selectively disrupts one of these recognition events to alter target-site occupancy (PMID:27401554). Beyond neurodevelopment, ZNF335 directly targets the fatty acid oxidation enzyme Hadha to drive effector regulatory T cell differentiation and suppressive function, with its loss causing lethal autoimmune inflammation (PMID:37843279). In humans, loss-of-function variants that reduce ZNF335 protein levels cause microcephaly (PMID:40583037).

1. 2002 High

   Defined ZNF335 as a nuclear zinc finger protein that boosts nuclear hormone receptor transcription not by binding receptors directly but as a cotransducer through the coactivator NRC, establishing its first molecular role.

   Evidence Yeast two-hybrid cloning, reciprocal in vivo/in vitro binding, domain mapping, and reporter assays in cells

   PMID:12215545

   Open questions at the time

   • Did not define the chromatin complex or enzymatic activity it scaffolds
   • No DNA-binding specificity established
2. 2007 Low

   Extended the cotransducer model by linking NIF-1 to the Mediator subunit Trap80, bridging NRC to p53-dependent transcription.

   Evidence Co-immunoprecipitation and transcriptional reporter assays

   PMID:17536006

   Open questions at the time

   • Single co-IP within a broader NRC-focused study; NIF-1/Trap80 interaction not independently validated
   • Functional significance for endogenous p53 targets untested
3. 2008 High

   Showed CCR4-NOT components physically engage NIF-1 and require it for nuclear receptor potentiation, placing ZNF335 as an obligate node in this coactivation pathway.

   Evidence Reciprocal in vivo/in vitro co-IP, siRNA knockdown with phenotypic dependence, qPCR, reporter assays

   PMID:18180299

   Open questions at the time

   • Mechanism by which CCR4-NOT enhances activity via ZNF335 unresolved
   • Direct target genes not mapped genome-wide
4. 2009 High

   Identified ZNF335 as the core scaffold of a ~1.5 MDa complex with Ash2L/RbBP5/WDR5/HCF-1/DBC-1/EMSY and showed the complex methylates a histone residue other than H3K4, defining its biochemical context for nuclear receptor target transcription.

   Evidence In-solution proteolysis/MS complex identification, histone methyltransferase activity assays, siRNA knockdown, qPCR

   PMID:19131338

   Open questions at the time

   • Exact methylated histone residue not identified
   • Catalytic subunit responsible for the activity not assigned
5. 2012 High

   Established ZNF335's developmental function: as part of a vertebrate-specific trithorax H3K4-methylation complex it directly regulates REST/NRSF and neural genes, and is essential for neural progenitor self-renewal and cortical size.

   Evidence Conditional KO mouse, RNAi, postmortem human tissue, biochemical complex identification

   PMID:23178126

   Open questions at the time

   • Apparent discrepancy between H3K4 and non-H3K4 methyltransferase activity across studies not reconciled
   • Direct genomic binding sites not yet mapped
6. 2014 Medium

   Revealed that NIF-1 subcellular distribution is dynamically controlled by CRM1-dependent export driven by the Cdk5 activator p35, independent of Cdk5 kinase activity.

   Evidence Co-IP, NES mutagenesis, leptomycin B inhibition, subcellular fractionation/imaging (single lab)

   PMID:25329792

   Open questions at the time

   • Not independently replicated
   • Functional consequence of shuttling for transcriptional output untested
7. 2015 Medium

   Connected ZNF335 to neuronal maturation by showing it is required for neurite outgrowth and that activity-induced Ca2+ influx drives its nuclear localization and activity-dependent transcription.

   Evidence siRNA knockdown, live-cell localization, neurite outgrowth assays, gene expression in primary cortical neurons (single lab)

   PMID:25573434

   Open questions at the time

   • Direct activity-dependent target genes not defined
   • Link between Ca2+ signaling and ZNF335 import mechanism unresolved
8. 2016 High

   Defined the DNA-recognition logic: ZNF335 uses two separate zinc finger clusters to read two distinct motifs, and the disease-linked R1092W mutation selectively abolishes one interaction, explaining target-selective dysfunction.

   Evidence ChIP-seq, DNA-binding assays, R1092W mutagenesis, reporter assays in mouse

   PMID:27401554

   Open questions at the time

   • How the two motif-binding modes integrate at composite sites unclear
   • Relationship of binding modes to specific cofactor recruitment not established
9. 2023 High

   Expanded ZNF335 function beyond neurodevelopment by showing it directly targets the FAO enzyme Hadha to license effector Treg differentiation and metabolism, with loss causing fatal autoimmunity.

   Evidence Treg-specific conditional KO, scRNA-seq, ChIP for direct Hadha targeting, OXPHOS/FAO metabolic assays, human eTreg correlation

   PMID:37843279

   Open questions at the time

   • Whether the chromatin complex defined in neural cells operates identically at Hadha untested
   • Full immune target repertoire not catalogued
10. 2024 Medium

    Linked ZNF335 to systemic metabolism by showing the R1092W hypomorph lowers non-HDL cholesterol and blunts statin response in vivo.

    Evidence Zfp335-R1092W mouse, plasma lipoprotein profiling, statin challenge, LCL transcriptomic correlation with human trial data (single lab)

    PMID:39061094

    Open questions at the time

    • Direct ZNF335 target genes mediating the cholesterol phenotype not identified
    • Not independently replicated
11. 2025 Medium

    Provided direct human disease evidence that a splicing variant reducing ZNF335 protein causes secondary microcephaly.

    Evidence Minigene splicing assay, exome sequencing, Western blot in a single patient case

    PMID:40583037

    Open questions at the time

    • Single case report
    • Mechanistic link from reduced protein to microcephaly phenotype inferred, not demonstrated
12. 2025 Low

    Suggested a previously unappreciated role in nuclear organization, as ZNF335 loss produces nucleoplasmic condensates in a genome-wide screen.

    Evidence Genome-wide CRISPR/Cas9 screen with high-content/confocal imaging (preprint)

    Open questions at the time

    • Preprint, not peer-reviewed
    • No molecular mechanism connecting ZNF335 to condensate biology
    • Relationship to its transcriptional/chromatin functions unknown

• The molecular identity of the histone residue and catalytic subunit responsible for the ZNF335 complex's methyltransferase activity, and how its DNA-binding modes select context-specific transcriptional and metabolic programs, remain unresolved.
• Methylated histone residue unassigned
• Genome-wide direct targets across cell types incompletely mapped
• Mechanistic basis of tissue-specific functions (neural vs. Treg vs. lipid) unknown