biology

RAD18

RAD18 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 RAD18 rather than just read about it. In short: E3 ubiquitin-protein ligase RAD18 is an enzyme that in humans is encoded by the RAD18 gene. A knockout in a human colorectal cancer cell line, HCT116, has also been created.

Key takeaways

RAD18 belongs to biology; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect RAD18 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of RAD18 from memory before moving on to harder problems.

Reference excerpt

E3 ubiquitin-protein ligase RAD18 is an enzyme that in humans is encoded by the RAD18 gene. A knockout in a human colorectal cancer cell line, HCT116, has also been created.

Function The protein encoded by this gene is highly similar to S. cerevisiae DNA damage repair protein Rad18. Yeast Rad18 functions through interaction with Rad6, which is a ubiquitin-conjugating enzyme required for post-replication repair of damaged DNA. Similar to its yeast counterpart, this protein is able to interact with the human homolog of yeast Rad6 protein through a conserved ring finger motif. Mutation of this motif results in defective replication of UV-damaged DNA and hypersensitivity to multiple mutagens. RAD18 is an E3 ubiquitin ligase that enables movement of ubiquitin from a ubiquitin carrier to another protein (the substrate). One activity of RAD18 is to prevent replication fork collapse by promoting DNA translesion synthesis and template switching. RAD18 is also involved in directing repair of DNA double-strand breaks by homologous recombination in post replicative chromatin. RAD18 appears to promote homologous recombinational repair by recruiting the SMC5,SMC6 (SMC5/6) complex to the DNA breaks.

Interactions RAD18 has been shown to interact with HLTF, UBE2B and UBE2A.

References

Illustrations

Worked examples

Example 1 — a first encounter with RAD18

Start with the simplest possible case. Write down what RAD18 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 RAD18 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 RAD18 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 RAD18

In research: RAD18 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 RAD18 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: RAD18 is common in secondary-school and first-year university syllabi. It links to neighbouring topics DNA repair, Genes mutated in mice, Genes on human chromosome 3, so understanding it makes those chapters shorter.
In everyday life: Look for RAD18 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 RAD18 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what RAD18 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 RAD18 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is RAD18 in simple terms?

E3 ubiquitin-protein ligase RAD18 is an enzyme that in humans is encoded by the RAD18 gene. A knockout in a human colorectal cancer cell line, HCT116, has also been created.

Why does RAD18 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 RAD18?

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 RAD18.