MIF4GD

Key takeaways

MIF4GD belongs to biology; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect MIF4GD to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of MIF4GD from memory before moving on to harder problems.

Reference excerpt

MIF4GD, or MIF4G domain-containing protein, is a protein which in humans is encoded by the MIF4GD gene. It is also known as SLIP1, SLBP (Stem-Loop Binding Protein)-interacting protein 1, AD023, and MIFD. MIF4GD is expressed ubiquitously in humans, and has been found to be involved in activating proteins for histone mRNA translation, alternative splicing and translation of mRNAs, and is a factor in the regulation of cell proliferation.

Gene The MIF4GD gene is located in humans on the minus strand of chromosome 17q25.1, and spans 5.0 Kb, from bases 75,266,228 to 75,271,292.

mRNA There are 11 alternatively-spliced mRNA transcripts and 3 unspliced mRNA transcripts that can be transcribed from this gene, which include 7 possible exons and 11 distinct introns.

Protein There are 10 viable isoforms of the MIF4G domain-containing protein. The longest isoform is MIF4G domain-containing protein isoform 1, which is 263 amino acids long, however, the most common isoform is MIF4G domain-containing protein isoform 4, which consists of 6 exons and is 222 amino acids in length.

Features MIF4G domain-containing protein isoform 1 has a predicted molecular weight of 30.1 kDa, and a predicted isoelectric point of 5.2, indicating that it is an acidic protein. It has a normal ratio of each amino acid when compared to the average human protein. Additionally, MIF4GD is expected to form 11 alpha helices.

Sub-cellular localization Searches of MIF4GD antibodies showed that MIF4GD is present in the cytoplasm and nucleoli of cells. Additionally, several bioinformatic programs predict human MIF4GD, as well as several of its orthologs, are present in the cytoplasm, nucleus and mitochondria of cells.

Post-translational modifications

Due to its presumed localization in the cytoplasm, it is predicted that MIF4GD could be phosphorylated, acetylated, ubiquitinated, or sumoylated. Additionally, MIF4GD is predicted to contain a "YinOYang" site at S61, which may be either O-GlcNAcylated or phosphorylated at different times for regulatory purposes. It is not likely that the MIF4GD protein will be lipid-linked or glycosylated.

MIF4G domain The MIF4GD protein that contains an MIF4G domain, which is named after the middle domain of eukaryotic initiation factor 4G (eIF4G).

The MIF4G domain of the MIF4GD protein has a molecular weight of 17.0 kDa, and has a predicted isoelectric point of 5.7. Similar to the entire protein, it contains normal ratios of each amino acid relative to a reference of human proteins, however, it contains less negatively-charged amino acids and more positively-charged amino acids relative to the entire protein. The MIF4G domain is predicted to contain many alpha-helices and is thought to contain alpha-helical repeats.

Expression and regulation MIF4GD is found only in animals, and is expressed ubiquitously in the body, though it has been discovered to be expressed at a somewhat higher rate in lymph nodes, bone marrow and testes. MIF4GD is expressed at an average rate that is 1.7 times higher than the average gene. The promoter region of MIF4GD is approximately 1137 nucleotide base pairs long, and is predicted to interact with various transcription factors. The 5' untranslated region of MIF4GD mRNA transcripts is relatively short, at a length of around 137 nucleotides, and is predicted to form stem-loops and interior-loops to which RNA-binding proteins may bind. The 3' untranslated region is longer, at a length of approximately 510 nucleotides. The 3' UTR is also predicted to form stem-loops, interior-loops, and bulge-loops, as well as more complex secondary structures, and is predicted to bind to RNA-binding proteins and miRNAs at or near these sites.

Interactants MIF4GD has been experimentally shown to bind to various other proteins, many of which play a role in alternative splicing of pre-mRNAs and translation of mRNAs into proteins. It also is known to interact with eukaryotic translation initiation factors, RNA, and DNA to form a translation initiation complex. Some of the most notable proteins that interact with MIF4GD are: ATP-dependent RNA helicases DDX19A and DDX19B, which is involved in mRNA export from the nucleus and helicase activity by facilitating the disassociation of nuclear mRNA binding proteins and replacement with cytoplasmic mRNA binding proteins. Cap binding complex dependent translation initiation factor, or CTIF, which is a paralog of MIF4GD. CTIF binds cotranscriptionally to the cap end of the nascent mRNA, and is involved in simultaneous editing and translation of mRNA that happens directly after export from the nucleus. Histone RNA hairpin-binding protein, or SLBP, which is involved in histone pre-mRNA processing and movement of mRNAs from the nucleus to the cytoplasm of cells. Supervillin, or SVIL, which is a peripheral membrane protein that forms a high-affinity link between the actin cytoskeleton and the membrane and contributes to myogenic membrane structure and differentiation. Supervillin also regulates cell spreading and motility during the cell cycle. MIF4GD also has been verified by two-hybrid bait-prey experiments to interact with NSP7ab, or Non-structural protein 7, of SARS-CoV.

Function and clinical significance MIF4GD has several known functions, including the activation of proteins that bind histone mRNAs for translation and binding of mRNAs for alternative splicing and translation into proteins. Additionally, down-regulation of the SLIP1/MIF4GD gene and corresponding protein results in a reduced rate of histone mRNA translation and reduced cell viability. Therefore, it is speculated to be needed in eukaryotic cells in order to produce proteins and for cell proliferation. MIF4GD has been shown to bind and stabilize p27Kip1, which plays an important role in the regulating the cell cycle and in cancer progression. When bound to MIF4GD, the stabilized protein suppresses phosphorylation by CDK2 at T187, which controls the amount of cell proliferation in hepatocellular carcinoma (HCC). Regulation of this interaction is being studied as a potential therapeutic treatment for patients with hepatocellular carcinoma. This provides more evidence that MIF4GD helps regulate cell proliferation, and suggests MIF4GD may play a role in immune response.

… excerpt ends here. Continue reading the full article.

Illustrations

MIF4GD: MIF4GD is located on human chromosome 17q25.1 (second white band from bottom). — MIF4GD is located on human chromosome 17q25.1 (second white band from bottom).

Worked examples

Example 1 — a first encounter with MIF4GD

Start with the simplest possible case. Write down what MIF4GD 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 MIF4GD 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 MIF4GD 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 MIF4GD

In research: MIF4GD 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 MIF4GD 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: MIF4GD is common in secondary-school and first-year university syllabi. It links to neighbouring topics Genes on human chromosome 17, Proteins, so understanding it makes those chapters shorter.
In everyday life: Look for MIF4GD 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.

How to study MIF4GD in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what MIF4GD 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 MIF4GD out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is MIF4GD in simple terms?

MIF4GD, or MIF4G domain-containing protein, is a protein which in humans is encoded by the MIF4GD gene. It is also known as SLIP1, SLBP (Stem-Loop Binding Protein)-interacting protein 1, AD023, and MIFD.

Why does MIF4GD 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 MIF4GD?

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 MIF4GD.