Synaptophysin, also known as the major synaptic vesicle protein p38, is a protein that in humans is encoded by the SYP gene.
Gene
The gene is located on the short arm of
X chromosome (Xp11.23-p11.22). It is 12,406 bases in length and lies on the minus strand.
Tissue distribution
It is expressed in neuroendocrine cells and in virtually all neurons in the
brain and
spinal cord that participate in synaptic transmission.
Structure
The protein is a
synaptic vesicle glycoprotein with four transmembrane domains weighing 38 kDa.
Function
The exact function of the protein is unknown: it interacts with the essential synaptic vesicle protein
synaptobrevin, but when the synaptophysin gene is experimentally inactivated in animals, they still develop and function normally.
Recent research has shown, however, that elimination of synaptophysin in mice creates behavioral changes such as increased exploratory behavior, impaired object novelty recognition, and reduced
spatial learning.
Clinical significance
Biomarker
It acts as a marker for neuroendocrine tumors, and its ubiquity at the synapse has led to the use of synaptophysin
immunostaining for quantification of synapses.
Using immunohistochemistry, synaptophysin can be demonstrated in a range of neural tissue and neuroendocrine tissues,
X-linked intellectual disability
Mutations in this gene have been implicated in X-linked intellectual disability.
Interactions
Synaptophysin has been shown to interact with AP1G1
and SIAH2.
See also
-
List of human genes
-
Merkel-cell carcinoma - although origin of this tumor is unclear, it does express synaptophysin
Further reading
External links
