biology

MTA3

MTA3 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 MTA3 rather than just read about it. In short: Metastasis-associated protein MTA3 is a protein that in humans is encoded by the MTA3 gene. MTA3 protein localizes in the nucleus as well as in other cellular compartments MTA3 is a component of the nucleosome remodeling and deacetylate (NuRD) complex and participates in gene expression.

Key takeaways

MTA3 belongs to biology; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect MTA3 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of MTA3 from memory before moving on to harder problems.

Reference excerpt

Metastasis-associated protein MTA3 is a protein that in humans is encoded by the MTA3 gene. MTA3 protein localizes in the nucleus as well as in other cellular compartments MTA3 is a component of the nucleosome remodeling and deacetylate (NuRD) complex and participates in gene expression. The expression pattern of MTA3 is opposite to that of MTA1 and MTA2 during mammary gland tumorigenesis. However, MTA3 is also overexpressed in a variety of human cancers.

Discovery Mouse Mta3 was initially identified as a partial cDNA with open reading frames in screening of a mouse keratinocyte cDNA library with a human MTA1 partial fragment by My G. Mahoney's research team. The full length Mta3 cDNA was cloned through 5'-RACE methodology using RNA from C57B1/6J mouse skin. The deduced amino acids and its comparison with sequences in NCBI GenBank established MTA3 as the third MTA family member.

Gene and spliced variants The Mta3 is localized on chromosome 12p in mice and MTA3 on 2p21 in human. The human MTA3 gene contains 20 exons, and 19 alternative spliced transcripts. Of these, nine MTA3 transcripts are predicted to code six proteins of 392, 514, 515, 537, 590 and 594 amino acids long, two MTA3 transcripts code 18 amino acids and 91 amino acids polypeptides. The remaining 10 transcripts are non-coding RNAs. The murine Mta3 gene contains nine transcripts, six of which are predicted to code proteins ranging from 251 amino acids to 591 amino acids while one transcript codes for 40 amino acids polypeptide. The murine Mta3 gene contains two predicted non-coding RNAs.

Structure The overall organization of MTA3 protein domains is similar to the other two family members with a BAH (Bromo-Adjacent Homology), an ELM2 domain (egl-27 and MTA1 homology), a SANT (SWI, ADA2, N-CoR, TFIIIB-B), a GATA-like zinc finger, and one predicted bipartite nuclear localization signal (NLS). The SH3 motif of Mta3 allows it to interact with Fyn and Grb2 – both SH3 containing signaling proteins.

Function Functions of MTA3 are believed to be differentially regulated in the context of cancer-types. For example, MTA3 expression is downregulated in breast cancer and endometrioid adenocarcinomas. MTA3 is overexpressed in non-small cell lung cancer and human placenta and chorionic carcinoma cells. In breast cancer, loss of MTA3 promotes EMT and invasiveness of breast cancer cells via upregulating Snail, which in turn represses E-cadherin adhesion molecule. In the mammary epithelium and breast cancer cells, MTA3 is an estrogen regulated gene and part of a larger regulatory network involving MTA1 and MTAs, all modifiers of hormone response, and participate in the processes involved in growth and differentiation. Accordingly, the MTA3-NuRD complex regulates the expression of Wnt4 in mammary epithelial cells and mice, and controls Wnt4-dependent ductal morphogenesis. In contrast to its repressive actions, MTA3 also stimulates the expression of HIF1α as well as its target genes under hypoxic conditions in trophoblasts and is thought to be involved in differentiation during pregnancy. MTA3-NuRD complex and downstream targets have been shown to participate in primitive hematopoietic and angiogenesis in a zebrafish model system As a part of BCL6 corepressor complex, MTA3 regulates BCL6-dependent repression of target genes, including PRDM1, and modulates the differentiation of B-cells.

Regulation The estrogen receptor-stimulates the expression of MTA3 in breast cancer cells. The SP1 transcription factor stimulates the transcription of MTA3. MicroRNA-495 inhibits the level of MTA3 mRNA as well as the growth and migration of non-small cell lung cancer cells. The β-elemene - a traditional Chinese medicine, upregulates MTA3's expression in breast cancer cells

Targets The MTA3-NuRD complex represses Snail, a master regulator of epithelial-to-mesenchymal transition (EMT), Wnt4 expression in mammary epithelial cells, and BCL6-corepressor target genes The MTA3-NuRD complex interacts with GATA3 to regulate the expression of GATA3 downstream targets. In addition, MTA3 upregulates HIF1 and its transactivation activity in hypoxic conditions.

Notes

References

External links MTA3+protein,+human at the U.S. National Library of Medicine Medical Subject Headings (MeSH) Overview of all the structural information available in the PDB for UniProt: Q924K8 (Mouse Metastasis-associated protein MTA3) at the PDBe-KB.

Illustrations

Worked examples

Example 1 — a first encounter with MTA3

Start with the simplest possible case. Write down what MTA3 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 MTA3 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 MTA3 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 MTA3

In research: MTA3 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 MTA3 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: MTA3 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Genes on human chromosome 2, Transcription factors, Wikipedia articles with corresponding academic peer reviewed articles, so understanding it makes those chapters shorter.
In everyday life: Look for MTA3 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 MTA3 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what MTA3 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 MTA3 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is MTA3 in simple terms?

Why does MTA3 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 MTA3?

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 MTA3.