biology

VDAC3

VDAC3 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 VDAC3 rather than just read about it. In short: Voltage-dependent anion-selective channel protein 3 (VDAC3) is a protein that in humans is encoded by the VDAC3 gene on chromosome 8. The protein encoded by this gene is a voltage-dependent anion channel and shares high structural homology with the other VDAC isoforms.

Key takeaways

VDAC3 belongs to biology; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect VDAC3 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of VDAC3 from memory before moving on to harder problems.

Reference excerpt

Voltage-dependent anion-selective channel protein 3 (VDAC3) is a protein that in humans is encoded by the VDAC3 gene on chromosome 8. The protein encoded by this gene is a voltage-dependent anion channel and shares high structural homology with the other VDAC isoforms. Nonetheless, VDAC3 demonstrates limited pore-forming ability in artificial membranes and, instead, interacts with other proteins to perform its biological functions, including sperm flagella assembly and centriole assembly. Mutations in VDAC3 have been linked to male infertility, as well as Parkinson's disease.

Structure The three VDAC isoforms in human are highly conserved, particularly with respect to their 3D structure. VDACs form a wide β-barrel structure, inside of which the N-terminal resides to partially close the pore. The sequence of the VDAC3 isoform contains an abundance of cysteines, which allow for the formation of disulfide bridges and, ultimately, affect the flexibility of the β-barrel. VDACs also contain a mitochondrial targeting sequence for the protein's translocation to the outer mitochondrial membrane. VDAC3 still yet possesses multiple isoforms, including a full-length form and shorter form termed VDAC3b. This shorter form is predominantly expressed over the full-length form at cell centrosomes.

Function VDAC3 belongs to the mitochondrial porin family and is expected to share similar biological functions to the other VDAC isoforms. VDACs are involved in cell metabolism by transporting ATP and other small metabolites across the outer mitochondrial membrane. In addition, VDACs form part of the mitochondrial permeability transition pore (MPTP) and, thus, facilitate cytochrome C release, leading to apoptosis. VDACs have also been observed to interact with pro- or antiapoptotic proteins, such as Bcl-2 family proteins and kinases, and so may contribute to apoptosis independently from the MPTP. Nonetheless, experiments reveal a lack of pore-forming ability in the VDAC3 isoform, suggesting that it may perform different biological functions. Notably, though all VDAC isoforms are ubiquitously expressed, VDAC3 is mostly found in the sperm outer dense fiber (ODF), where it is hypothesized to promote proper assembly and maintenance of sperm flagella. Because the ODF membranes are not likely to support pore formation, VDAC3 may interact with protein partners to carry out other functions in the ODF. For instance, within cells, VDAC3 predominantly localizes to the centrosome and recruits Mps1 to regulate centriole assembly. In the case of localization to the mitochondria, VDAC3 interaction with Mps1 instead leads to ciliary disassembly.

… excerpt ends here. Continue reading the full article.

Illustrations

Worked examples

Example 1 — a first encounter with VDAC3

Start with the simplest possible case. Write down what VDAC3 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 VDAC3 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 VDAC3 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 VDAC3

In research: VDAC3 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 VDAC3 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: VDAC3 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Genes on human chromosome 8, Ion channels, so understanding it makes those chapters shorter.
In everyday life: Look for VDAC3 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.

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How to study VDAC3 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what VDAC3 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 VDAC3 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is VDAC3 in simple terms?

Why does VDAC3 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 VDAC3?

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 VDAC3.