Core-binding factor subunit beta

Core-binding factor subunit beta (CBFB) is a 182-amino acid regulatory protein that forms heterodimeric complexes with RUNX family transcription factors (RUNX1, RUNX2, RUNX3) (UniProt: Q13951). Although CBFB itself does not bind DNA directly, it allosterically enhances the sequence-specific DNA-binding capacity of RUNX proteins to core consensus sequences, enabling the CBF complex to modulate transcription of target genes involved in T-cell development, hematopoiesis, and other processes. CBFB can also be hijacked during HIV-1 infection as part of a cullin-5-dependent ubiquitin ligase complex.

Germline CBFB mutations are associated with cleidocranial dysplasia type 2 (CLCD2), an autosomal dominant skeletal disorder characterized by delayed ossification, clavicular hypoplasia, dental anomalies, and variable developmental delay (UniProt: Q13951).

CBFB is upregulated in Alzheimer's disease brain tissue. Analysis of post-mortem AD brain samples versus age-matched controls by quantitative proteomics detected CBFB across multiple subcellular fractions with a mean log2 fold-change of 0.70, indicating consistent elevation (Chaparral AD proteomics). This upregulation suggests potential involvement in AD-related transcriptional dysregulation or neuroinflammatory pathways.