KAP1 (KRAB-associated protein 1), also known as TRIM28 or TIF1β, is a multifunctional transcriptional regulator critical for epigenetic silencing and chromatin remodeling. It serves as a co-repressor for KRAB domain-containing zinc finger proteins (KRAB-ZFPs), mediating gene silencing by recruiting histone-modifying enzymes like SETDB1 (a histone methyltransferase) and HP1 (heterochromatin protein 1) to establish heterochromatin. KAP1 plays pivotal roles in embryonic development, genomic imprinting, and retrotransposon suppression.
Structurally, KAP1 contains a RBCC motif (RING, B-box, coiled-coil) and a PHD-bromodomain, enabling interactions with chromatin and other proteins. Post-translational modifications, such as phosphorylation and SUMOylation, regulate its activity. For example, phosphorylation at Ser824 modulates its role in DNA damage response.
KAP1 antibodies are essential tools in studying these processes. They are widely used in techniques like Western blotting, immunoprecipitation, and immunofluorescence to detect KAP1 expression, localization, and interactions. In research, KAP1 dysregulation is linked to cancer, viral latency, and neurological disorders. Antibodies against specific epitopes or modified forms (e.g., phosphorylated KAP1) help dissect its context-dependent functions. Commercial KAP1 antibodies are typically validated for specificity across human, mouse, and rat samples, supporting diverse experimental models.