Coatomer subunit beta'

Coatomer subunit beta' (COPB2) is a core component of the coatomer complex, a cytosolic protein machinery essential for vesicular trafficking between the endoplasmic reticulum and Golgi apparatus (UniProt: P35606). The complex mediates retrograde transport of dilysine-tagged proteins and is required for Golgi budding and structural integrity. COPB2 selectively binds protein kinase C epsilon and associates with Golgi membranes in a GTP-dependent manner.

COPB2 is implicated in neurodevelopmental and bone disorders. Genetic variations are associated with microcephaly 19 (MCPH19), characterized by severe developmental delay and cortical malformation, as well as childhood-onset osteoporosis with developmental delay (OPDD) (UniProt: P35606). These associations highlight the protein's importance in normal neural and skeletal development.

In Alzheimer's disease, COPB2 is significantly upregulated in post-mortem AD brain tissue compared to age-matched controls (Chaparral AD proteomics). The protein showed a mean log2 fold-change of +0.33 across analyzed subcellular fractions in TMT-labeled tandem mass spectrometry. This upregulation may reflect alterations in vesicular trafficking and protein secretion pathways implicated in amyloid or tau pathology.