biology

METTL3

METTL3 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 METTL3 rather than just read about it. In short: N6-adenosine-methyltransferase 70 kDa subunit (METTL3) is an enzyme that in humans is encoded by the METTL3 gene. METTL3 is located on the human chromosome 14q11.2 (Cancer Biology) and out of the METTL protein family, it is the most studied.

Key takeaways

METTL3 belongs to biology; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect METTL3 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of METTL3 from memory before moving on to harder problems.

Reference excerpt

N6-adenosine-methyltransferase 70 kDa subunit (METTL3) is an enzyme that in humans is encoded by the METTL3 gene. METTL3 is located on the human chromosome 14q11.2 (Cancer Biology) and out of the METTL protein family, it is the most studied. This gene encodes the 70 kDa subunit of MT-A which is part of N6-adenosine-methyltransferase. This enzyme is involved in the post-transcriptional methylation of internal adenosine residues in eukaryotic mRNAs, forming N6-methyladenosine (m6A). METTL3 forms the m6 a methyltransferase complex with METTL14 and WTP and is responsible for a majority of the m6a modifications of mRNA. The most common modification being the catalyzation of m6a with the methyltransferase complex. METTL3 is expressed in a variety of normal tissues, such as the lymphoid, testis, prostate and fallopian tube tissues. The enzyme is also responsible for mechanisms related to tumor development, RNA stability and maturation, and has suggested roles in ensuring animal survival.

Function

The m6A methyltransferase complex In the m6a methyltransferase complex (MTC), METTL3 is a part of the m6A "writers" and is a core catalytic component. METTL3 interacts with S-adenosylmethionine (SAM), a methyl donor to catalyze the formation of the MTC complex via methyl transfer. METTL3 forms the heterodimer complex with METTL3, binds to SAM and interacts with substrate RNA to transfer methyl groups to target RNA. The complex can also bind to target RNA using WTAP. After a METTL3-METTL14-WTAP complex forms, METTL3 can bind to RBM15. Then, MTC can be recruited at specific sites in the RNA.

In cancer METTL3 acts as an m6a methyltransferase in cancer, mostly as an oncogene, and sometimes a tumor suppressor. In most examples, METTL3 promotes the initiation and development of cancers such as lung, liver, gastric, prostate and breast cancer. METTL3 does so through applying m6a modifications on crucial mediators and transcripts. An example of this is METTL3 expression in pancreatic cancer. In pancreatic cancer, METTL3 expression applies m6a modifications onto the oncogene primary miR-25, provoking malignant transformation via enhanced maturation of the miRNA. In a few cases, METTL3 acts as a tumor suppressor. The m6a mRNA modifications from METTL3 can promote tumor suppressor proliferation, migration, and invasion. In colorectal cancer, METTL3 promotes the tumor suppressor through p38/ERK pathways.

References

Illustrations

Worked examples

Example 1 — a first encounter with METTL3

Start with the simplest possible case. Write down what METTL3 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 METTL3 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 METTL3 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 METTL3

In research: METTL3 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 METTL3 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: METTL3 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Genes on human chromosome 14, Human chromosome 14 gene stubs, so understanding it makes those chapters shorter.
In everyday life: Look for METTL3 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 METTL3 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what METTL3 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 METTL3 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is METTL3 in simple terms?

Why does METTL3 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 METTL3?

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 METTL3.