biology

UQCRB

UQCRB 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 UQCRB rather than just read about it. In short: Ubiquinol-cytochrome c reductase binding protein, also known as UQCRB, Complex III subunit 7, QP-C, or Ubiquinol-cytochrome c reductase complex 14 kDa protein is a protein which in humans is encoded by the UQCRB gene. This gene encodes a subunit of the ubiquinol-cytochrome c oxidoreductase complex, which consists of one mitochondrial-encoded and 10 nuclear-encoded subunits.

Key takeaways

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

Reference excerpt

Ubiquinol-cytochrome c reductase binding protein, also known as UQCRB, Complex III subunit 7, QP-C, or Ubiquinol-cytochrome c reductase complex 14 kDa protein is a protein which in humans is encoded by the UQCRB gene. This gene encodes a subunit of the ubiquinol-cytochrome c oxidoreductase complex, which consists of one mitochondrial-encoded and 10 nuclear-encoded subunits. Mutations in this gene are associated with mitochondrial complex III deficiency. Alternatively spliced transcript variants have been found for this gene. Related pseudogenes have been identified on chromosomes 1, 5 and X.

Structure UQCRB is located on the q arm of chromosome 8 in position 22.1, has 18 exons, and spans 8,958 base pairs. The UQCRB gene produces a 5.9 kDa protein composed of 161 amino acids. The gene product of UQCRB is a subunit of the respiratory chain protein Ubiquinol Cytochrome c Reductase (UQCR, Complex III or Cytochrome bc1 complex; E.C. 1.10.2.2), which consists of the products of one mitochondrially encoded gene, MTCYTB (mitochondrial cytochrome b) and ten nuclear genes: UQCRC1, UQCRC2, Cytochrome c1, UQCRFS1 (Rieske protein), UQCRB, "14kDa protein", UQCRH (cyt c1 Hinge protein), Rieske Protein presequence, "cyt. c1 associated protein", and "Rieske-associated protein". After processing, the cleaved leader sequence of the iron-sulfur protein is retained as subunit 9, giving 11 subunits from 10 genes.

Function The ubiquinone-binding protein is a nucleus-encoded component of ubiquinol-cytochrome c oxidoreductase (Complex III) in the mitochondrial respiratory chain and plays an important role in electron transfer as a complex of ubiquinone and QP-C. The protein encoded by this gene binds ubiquinone and participates in the transfer of electrons when ubiquinone is bound. It is a target of a protein named natural anti-angiogenic small molecule terpestacin, which enables the role of the ubiquinone-binding protein as cellular oxygen sensors and participants in angiogenesis. This angiogenesis, which is the development of new blood vessels, is hypoxia induced and is facilitated by signaling mediated by mitochondrial ROS (reactive oxygen species). In addition, UQCRB keeps maintenance of complex III.

Clinical significance Mutations in UQCRB can result in mitochondrial deficiencies and associated disorders. It is majorly associated with a complex III deficiency, a deficiency in an enzyme complex which catalyzes electron transfer from coenzyme Q to cytochrome c in the mitochondrial respiratory chain. A complex III deficiency can result in a highly variable phenotype depending on which tissues are affected. Most frequent clinical manifestations include progressive exercise intolerance and cardiomyopathy. Occasional multisystem disorders accompanied by exercise intolerance may arise as well, in forms of deafness, mental retardation, retinitis pigmentosa, cataract, growth retardation, and epilepsy. Other phenotypes include mitochondrial encephalomyopathy, mitochondrial myopathy, Leber hereditary optic neuropathy, muscle weakness, myoglobinuria, blood acidosis, renal tubulopathy, and more. Complex III deficiency is known to be rare among mitochondrial diseases.

Interactions UQCRB has binary interactions with 3 proteins, including MAGA4, Q1RN33, and 1A1L1. In addition, SDHAF2 has 69 protein-protein interactions, including COX6B1, CYC1, MYO18A, UHRF1, and others.

References

Illustrations

Worked examples

Example 1 — a first encounter with UQCRB

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

In research: UQCRB 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 UQCRB 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: UQCRB is common in secondary-school and first-year university syllabi. It links to neighbouring topics Genes on human chromosome 8, Mitochondrial proteins, so understanding it makes those chapters shorter.
In everyday life: Look for UQCRB 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 UQCRB in 20 minutes

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

Frequently asked questions

What is UQCRB in simple terms?

Why does UQCRB 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 UQCRB?

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 UQCRB.