biology

Macrophage migration inhibitory factor

Macrophage migration inhibitory factor 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 Macrophage migration inhibitory factor rather than just read about it. In short: Macrophage migration inhibitory factor (MIF), also known as glycosylation-inhibiting factor (GIF), L-dopachrome isomerase, or phenylpyruvate tautomerase is a protein that in humans is encoded by the MIF gene. MIF is an important regulator of innate immunity.

Key takeaways

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

Reference excerpt

Macrophage migration inhibitory factor (MIF), also known as glycosylation-inhibiting factor (GIF), L-dopachrome isomerase, or phenylpyruvate tautomerase is a protein that in humans is encoded by the MIF gene. MIF is an important regulator of innate immunity. The MIF protein superfamily also includes a second member with functionally related properties, the D-dopachrome tautomerase (D-DT). CD74 is a surface receptor for MIF. Bacterial antigens stimulate white blood cells to release MIF into the blood stream. The circulating MIF binds to CD74 on other immune cells to trigger an acute immune response. Hence, MIF is classified as an inflammatory cytokine. Furthermore, glucocorticoids also stimulate white blood cells to release MIF and hence MIF partially counteracts the inhibitory effects that glucocorticoids have on the immune system. Finally trauma activates the anterior pituitary gland to release MIF.

Structure Macrophage migration inhibitory factor assembles into a trimer composed of three identical subunits. Each of these monomers contain two antiparallel alpha helices and a four-stranded beta sheet. The monomers surround a central channel with 3-fold rotational symmetry. MIF contains two motifs with catalytic activity. The first is a 27 amino acid motif located at the N-terminus functions as a phenylpyruvate tautomerase that can catalyze the conversion of 2-carboxy-2,3-dihydroindole-5,6-quinone (dopachrome) into 5,6-dihydroxyindole-2-carboxylic acid (DHICA). MIF also contains a Cys-Ala-Leu-Cys catalytic site between residues 57 and 60 that appears to function as a disulfide reductase.

Mechanism of action MIF binds to CD74, inducing its phosphorylation and the recruitment of CD44 which then activates non-receptor tyrosine kinases, leading ultimately to extracellular signal-regulated kinase phosphorylation. In addition to ERK, stimulation of CD74 activates other signaling pathways such PI3K-Akt, NF-κB, and AMP-activated protein kinase (AMPK) pathways.

Function This gene encodes a lymphokine involved in cell-mediated immunity, immunoregulation, and inflammation. MIF plays a role in the regulation of macrophage function in host defense through the suppression of anti-inflammatory effects of glucocorticoids. This lymphokine and the JAB1 protein form a complex in the cytosol near the peripheral plasma membrane, which may indicate a role in integrin signaling pathways. Cytokines play an important role in promoting wound healing and tissue repair. Cell injury results in MIF release which then interacts with CD74. MIF-CD74 signaling activates pro-survival and proliferative pathways that protects the host during injury.

Interactions Macrophage migration inhibitory factor has been reported to interact with:

BNIPL, CD74, COPS5, CXCR4, and RPS19.

Clinical significance MIF is a potential drug target for sepsis, rheumatoid arthritis, and cancer.

Parasite-produced MIF homologs

Multiple protozoan parasites produce homologs MIF that have similar inflammatory functions to human MIF, and play a role in their pathogenesis, invasion and immune evasion. A preclinical study showed that blocking parasite MIF improves outcome in severe protozoan infections. Examples of protozoans with MIF homologs that have been reported:

Entamoeba histolytica, Plasmodium falciparum, Toxoplasma gondii, Leishmania, Trichomonas vaginalis.

References

External links Media related to Macrophage migration inhibitory factor at Wikimedia Commons

Illustrations

Worked examples

Example 1 — a first encounter with Macrophage migration inhibitory factor

Start with the simplest possible case. Write down what Macrophage migration inhibitory factor 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 Macrophage migration inhibitory factor 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 Macrophage migration inhibitory factor 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 Macrophage migration inhibitory factor

In research: Macrophage migration inhibitory factor 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 Macrophage migration inhibitory factor 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: Macrophage migration inhibitory factor is common in secondary-school and first-year university syllabi. It links to neighbouring topics Genes on human chromosome 22, Immune system, so understanding it makes those chapters shorter.
In everyday life: Look for Macrophage migration inhibitory factor 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.

Ask Teacher Smith questions about this articleOpens your AI tutor with a question about “Macrophage migration inhibitory factor” →

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Macrophage migration inhibitory factor in 20 minutes

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

Frequently asked questions

What is Macrophage migration inhibitory factor in simple terms?

Why does Macrophage migration inhibitory factor 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 Macrophage migration inhibitory factor?

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 Macrophage migration inhibitory factor.