Exocyst complex component 6B

Exocyst complex component 6B (EXOC6B) is a structural protein that functions as a component of the exocyst complex, which mediates the docking of exocytic vesicles at the plasma membrane (UniProt: Q9Y2D4). This protein plays an essential role in membrane trafficking and cellular secretion pathways. In the UniProt database, EXOC6B is associated with spondyloepimetaphyseal dysplasia with joint laxity, type 3 (SEMDJL3), an autosomal recessive skeletal disorder characterized by joint dislocations and delayed ossification.

In Alzheimer's Disease, EXOC6B shows evidence of reduced expression in post-mortem AD brain tissue compared to age-matched controls (Chaparral AD proteomics). The mean log2 fold-change is −0.3147 across the measured subcellular fractions, indicating a modest downregulation. This finding derives from TMT-labeled quantitative proteomics analysis of four subcellular fractions from human post-mortem brain samples. The downregulation of exocyst components in AD may reflect impaired vesicle trafficking and secretory defects that could contribute to pathological accumulation of proteins or disrupted synaptic function in neurodegeneration.