biology

Synaptophysin

Synaptophysin is a biology topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Synaptophysin rather than just read about it. In short: 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).

Key takeaways

Synaptophysin belongs to biology; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Synaptophysin to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Synaptophysin from memory before moving on to harder problems.

Reference excerpt

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 and neuroendocrine tissues, including cells of the adrenal medulla and pancreatic islets. As a specific marker for these tissues, it can be used to identify tumours arising from them, such as neuroblastoma, retinoblastoma, phaeochromocytoma, carcinoid, small-cell carcinoma, medulloblastoma and medullary thyroid carcinoma, among others. Diagnostically, it is often used in combination with chromogranin A.

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

References

Illustrations

Worked examples

Example 1 — a first encounter with Synaptophysin

Start with the simplest possible case. Write down what Synaptophysin claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In biology, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Synaptophysin before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Synaptophysin ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Synaptophysin

In research: Synaptophysin appears in biology research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Synaptophysin in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Synaptophysin is common in secondary-school and first-year university syllabi. It links to neighbouring topics Genes on human chromosome X, Glycoproteins, Tumor markers, so understanding it makes those chapters shorter.
In everyday life: Look for Synaptophysin outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Synaptophysin in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Synaptophysin means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Synaptophysin out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Synaptophysin in simple terms?

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).

Why does Synaptophysin matter?

Because it connects several biology ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Synaptophysin?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Synaptophysin.