biology

Toll-interleukin receptor

Toll-interleukin receptor 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 Toll-interleukin receptor rather than just read about it. In short: The Toll/Interleukin-1 receptor/Resistance protein (TIR) homology domain is an intracellular signaling domain found in MyD88, SARM1, interleukin-1 receptors, toll receptors and many plant R proteins. It contains three highly conserved regions, and mediates protein-protein interactions between the toll-like receptors (TLRs) and signal-transduction components.

Key takeaways

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

Reference excerpt

The Toll/Interleukin-1 receptor/Resistance protein (TIR) homology domain is an intracellular signaling domain found in MyD88, SARM1, interleukin-1 receptors, toll receptors and many plant R proteins. It contains three highly conserved regions, and mediates protein-protein interactions between the toll-like receptors (TLRs) and signal-transduction components. TIR-like motifs are also found in plant proteins where they are involved in resistance to disease and in bacteria where they are associated with virulence. When activated, TIR domains recruit cytoplasmic adaptor proteins MyD88 (UniProt Q99836) and TOLLIP (toll-interacting protein, UniProt Q9H0E2). In turn, these associate with various kinases to set off signaling cascades. Some TIR domains have also been found to have intrinsic NAD+ cleavage activity, such as in SARM1. In the case of SARM1, the TIR NADase activity leads to the production of Nam, ADPR and cADPR and the activation of downstream pathways involved in Wallerian degeneration and neuron death. In Drosophila melanogaster the toll protein is involved in establishment of dorso-ventral polarity in the embryo. In addition, members of the toll family play a key role in innate antibacterial and antifungal immunity in insects as well as in mammals. These proteins are type-I transmembrane receptors that share an intracellular 200 residue domain with the interleukin-1 receptor (IL-1R), the toll/IL-1R homologous region (TIR). The similarity between toll-like receptors (TLRs) and IL-1R is not restricted to sequence homology since these proteins also share a similar signaling pathway. They both induce the activation of a Rel type transcription factor via an adaptor protein and a protein kinase. MyD88, a cytoplasmic adaptor protein found in mammals, contains a TIR domain associated to a DEATH domain. Besides the mammalian and Drosophila melanogaster proteins, a TIR domain is also found in a number of plant proteins implicated in host defense. As MyD88, these proteins are cytoplasmic. Site directed mutagenesis and deletion analysis have shown that the TIR domain is essential for toll and IL-1R activities. Sequence analysis have revealed the presence of three highly conserved regions among the different members of the family: box 1 (FDAFISY), box 2 (GYKLC-RD-PG), and box 3 (a conserved W surrounded by basic residues). It has been proposed that boxes 1 and 2 are involved in the binding of proteins involved in signaling, whereas box 3 is primarily involved in directing localization of receptor, perhaps through interactions with cytoskeletal elements.

Subfamilies Interleukin-1 receptor InterPro: IPR004075

Human proteins containing this domain IL18R1; IL18RAP; IL1R1; IL1RAP; IL1RAPL1; IL1RAPL2; IL1RL1; IL1RL2; MYD88; SIGIRR; TLR1; TLR10; TLR2; TLR3; TLR4; TLR5; TLR6; TLR7; TLR8; TLR9; SARM1;

References

Illustrations

Worked examples

Example 1 — a first encounter with Toll-interleukin receptor

Start with the simplest possible case. Write down what Toll-interleukin receptor 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 Toll-interleukin receptor 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 Toll-interleukin receptor 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 Toll-interleukin receptor

In research: Toll-interleukin receptor 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 Toll-interleukin receptor 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: Toll-interleukin receptor is common in secondary-school and first-year university syllabi. It links to neighbouring topics Protein domains, Protein families, Single-pass transmembrane proteins, so understanding it makes those chapters shorter.
In everyday life: Look for Toll-interleukin receptor 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 Toll-interleukin receptor in 20 minutes

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

Frequently asked questions

What is Toll-interleukin receptor in simple terms?

Why does Toll-interleukin receptor 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 Toll-interleukin receptor?

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 Toll-interleukin receptor.