THAP10

Model summary

A nuclear regulatory protein that uses an N-terminal THAP-type zinc finger to anchor onto chromatin and assemble repressive complexes in the nucleoplasm. By scaffolding interactions with other nuclear factors, it dampens RNA polymerase II–driven transcription through promoter-proximal and chromatin-mediated repression rather than enzymatic catalysis, thereby tuning gene expression programs within the nucleus.

Predicted Gene Ontology terms

1. 01

   I begin with the InterPro architecture.

   The N-terminus carries IPR006612 (THAP-type zinc finger, residues 1–96), a C2CH zinc-coordinating module that folds into a DNA- and chromatin-recognition domain frequently used by transcriptional regulators. Nested within this region is IPR038441 (THAP-type zinc finger superfamily, residues 5–79), reinforcing that the core of the protein is a THAP fold. The ordered layout—an N-terminal THAP domain followed by a largely THAP-specified remainder—implies that the entire polypeptide is built around nucleic acid and chromatin engagement rather than enzymatic catalysis. This architecture causes avid macromolecular binding, especially to other regulatory proteins and nucleoprotein assemblies, which supports GO:0005515 protein binding as the molecular function.

2. 02

   A THAP-centered scaffold typically modulates transcription by docking onto promoters or enhancers and recruiting repression machinery.

   Such docking and recruitment causally lead to decreased transcriptional output from RNA polymerase II target genes, aligning with GO:0000122 negative regulation of transcription by RNA polymerase II. The absence of catalytic motifs and the presence of a single, high-specificity interaction module suggest that repression is achieved through assembly of inhibitory complexes rather than covalent modification.

3. 03

   Cellular localization follows from function and fold.

   THAP domains localize to chromatin-rich nuclear territories, and transcriptional repression complexes operate in the soluble phase of the nucleus. This points to a soluble nuclear compartment, consistent with GO:0005654 nucleoplasm and a broader nuclear residence. The experimentally observed nuclear localization is mechanistically explained by the THAP domain’s affinity for chromatin-associated targets.

4. 04

   Mechanistically, the THAP module nucleates a repressive hub by binding partner proteins and chromatin, then stabilizing assemblies that attenuate RNA polymerase II initiation or elongation.

   Likely partners include nuclear corepressors and chromatin-modifying enzymes that the THAP fold can recruit through multivalent protein binding. I therefore hypothesize interactions with transcriptional corepressors and histone-modifying assemblies that together enforce promoter-proximal repression within the nucleoplasm.