biology

Kinesin-associated protein 3

Kinesin-associated protein 3 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 Kinesin-associated protein 3 rather than just read about it. In short: Kinesin-associated protein 3 (KAP3) is a protein that in humans is encoded by the KIFAP3 gene. It is a non-motor, accessory subunit which co-oligomerizes with the motor subunits KIF3A and KIF3B or KIF3C, to form heterotrimeric kinesin-2 motor proteins.

Key takeaways

Kinesin-associated protein 3 belongs to biology; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Kinesin-associated protein 3 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Kinesin-associated protein 3 from memory before moving on to harder problems.

Reference excerpt

Kinesin-associated protein 3 (KAP3) is a protein that in humans is encoded by the KIFAP3 gene. It is a non-motor, accessory subunit which co-oligomerizes with the motor subunits KIF3A and KIF3B or KIF3C, to form heterotrimeric kinesin-2 motor proteins. Kinesin-2 KAP subunits were initially characterized in echinoderms and mice.

Function The small G protein GDP dissociation stimulator (smg GDS) is a regulator protein having two activities on a group of small G proteins including the Rho and Rap1 family members and Ki-Ras; one is to stimulate their GDP/GTP exchange reactions, and the other is to inhibit their interactions with membranes. The protein encoded by this gene contains 9 Armadillo repeats and interacts with the smg GDS protein through these repeats. This protein, which is highly concentrated around the endoplasmic reticulum, is phosphorylated by v-src, and this phosphorylation reduces the affinity of the protein for smg GDS. It is thought that this protein serves as a linker between human chromosome-associated polypeptide (HCAP) and KIF3A/B, a kinesin superfamily protein in the nucleus, and that it plays a role in the interaction of chromosomes with an ATPase motor protein. It has also been proposed to act as a clamp, stabilizing the C-terminal half of the otherwise unstable stalk coiled-coil.

Interactions KIFAP3 has been shown to interact with APC, SMC3 and RAP1GDS1.

References

Illustrations

Worked examples

Example 1 — a first encounter with Kinesin-associated protein 3

Start with the simplest possible case. Write down what Kinesin-associated protein 3 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 Kinesin-associated protein 3 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 Kinesin-associated protein 3 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 Kinesin-associated protein 3

In research: Kinesin-associated protein 3 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 Kinesin-associated protein 3 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: Kinesin-associated protein 3 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Armadillo-repeat-containing proteins, Genes on human chromosome 1, Human chromosome 1 gene stubs, so understanding it makes those chapters shorter.
In everyday life: Look for Kinesin-associated protein 3 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 Kinesin-associated protein 3 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Kinesin-associated protein 3 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 Kinesin-associated protein 3 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Kinesin-associated protein 3 in simple terms?

Why does Kinesin-associated protein 3 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 Kinesin-associated protein 3?

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 Kinesin-associated protein 3.