Trafficking Protein Particle Complex 4 (TRAPPC4)

TRAPPC4, the deduced 219-amino acid protein contains segments of homology with proteins involved in vesicular transport or synaptic function, including a nonclassical PDZ domain, followed by a TRAPPC1-like domain, and a C-terminal tail similar to a short cytoplasmic segment of RYR2.

In adult mouse CNS, expression was highest in large neurons such as pyramidal neurons, Purkinje cells, and motor neurons and weak or undetectable in smaller granule-type neurons. Immunogold electron microscopy of adult mouse cerebral cortex detected synbindin predominantly in postsynaptic membranes and postsynaptic densities, intracellular vesicles in the dendritic shaft, membrane cisternae, and in the Golgi apparatus.