biology

PTCHD4

PTCHD4 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 PTCHD4 rather than just read about it. In short: Patched Domain-Containing Protein 4 (PTCHD4) is a protein, which in humans is encoded by the Patched Domain-Containing Protein 4 gene. It is otherwise known by the aliases: PTCHD4, C6orf138, dj402H5.2, and by the accession number BC137364.

Key takeaways

PTCHD4 belongs to biology; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect PTCHD4 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of PTCHD4 from memory before moving on to harder problems.

Reference excerpt

Patched Domain-Containing Protein 4 (PTCHD4) is a protein, which in humans is encoded by the Patched Domain-Containing Protein 4 gene. It is otherwise known by the aliases: PTCHD4, C6orf138, dj402H5.2, and by the accession number BC137364.

Homology

Orthologs Sequenced distant orthologs of human PTCHD4 have been found as far back in evolution as mold, which shows a conservation of 16% identity. Strict orthologs include boneless fish, but not echinoderms, insects, or plants.

Paralogs PTCHD4 has three other genes in its family: PTCHD1, PTCHD2, and PTCHD3, as well as the Niemann-Pick disease type C protein. These paralogs are far less conserved than strict orthologs, which may suggest that they split long before speciation.

Gene Human PTCHD4 is located on the negative strand of chromosome 6, at 6p12.3. From there, it covers 190,350 base pairs, which includes three exons and two introns.

Expression Nominal expression of PTCHD4 was found in the brain, connective tissue, embryonic tissue, lungs, placenta, testis, trachea, and uterus, with the greatest expression in the trachea. Nominal expression was also found in the following disease states: chondrosarcoma, germ cell tumors, non-neoplasia, and uterine tumors. Protein localization was found in all tissues examined except the salivary glands, yet RNA expression was scarcely found anywhere. This may suggest that PTCHD4 protein is particularly resilient to degradation, and that it is only produced under key circumstances or at key life stages.

Protein Homo sapiens PTCHD4 variant 1 is 846 amino acids in length, weighs 96.4 kilodaltons, and has an isoelectric point of 8.8. It has two isomers, which are denoted as variant 2 and variant X1. It is phenylalanine rich, and found in the cell membrane.

Structure Phyre2 extrapolated the following 3D secondary structure with 100% certainty after analyzing 745 residues, (an 88% majority) of PTCHD4’s human protein sequence. Results were remarkably similar in such distant orthologs as earthworms, boneless fish, and green algae. There are an estimate 10 transmembrane helices.

Predicted function PTCHD4 has been implicated as an integral component of cellular membrane, and as a protein receptor in the hedgehog pathway. The later of these two functions causes an inhibitory effect during the development of embryonic cells in all bilaterians and vertebrates. In mammals, the hedgehog pathway is vital to the proper development of the brain, skeleton, musculature, gastrointestinal tract, and lungs. It also appears to be important to adult animals, as it has been implicated in the regulation of adult stem cells, while its malfunction is associated basal cell carcinoma.

References

Worked examples

Example 1 — a first encounter with PTCHD4

Start with the simplest possible case. Write down what PTCHD4 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 PTCHD4 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 PTCHD4 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 PTCHD4

In research: PTCHD4 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 PTCHD4 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: PTCHD4 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Proteins, so understanding it makes those chapters shorter.
In everyday life: Look for PTCHD4 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 PTCHD4 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what PTCHD4 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 PTCHD4 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is PTCHD4 in simple terms?

Why does PTCHD4 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 PTCHD4?

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 PTCHD4.