TRAPPC14

Key takeaways

TRAPPC14 belongs to biology; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect TRAPPC14 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of TRAPPC14 from memory before moving on to harder problems.

Reference excerpt

TRAPPC14 (trafficking protein particle complex subunit 14) also known as MAP11 (microtubule-associated protein 11) is a protein that in human is encoded by the gene TRAPPC14. It was previously referred to by the generic name C7orf43. C7orf43 has no other human alias, but in mice can be found as BC037034.

Gene Locus In humans, MAP11 is located in the long arm of human chromosome 7 (7q22.1), and is on the negative (antisense) strand. Genes located around C7orf43 include GAL3ST4, LAMTOR4, GPC2. In humans, C7orf43 has 9 detected common single-nucleotide polymorphisms (SNPs), all of which are located in non-coding regions and thus do not affect amino acid sequence.

mRNA

Splice variants

MAP11 encodes 2 isoforms, the longest being C7orf43 isoform 1, which is 2585 base pairs long and has with 11 exons and 10 introns. C7orf43 isoform 1 encodes a protein that is 580 amino acids long and only has one polyadenylation site. C7orf43 isoform 2 is 2085 base pairs long and encodes a protein of 311 amino acids. Two additional isoforms has been reported on several occasions, encoding for proteins with 199 and 206 amino acids.

Tissue expression MAP11 has a widespread moderate expression with tissue to tissue variability in humans and across mammalian species. The mouse C7orf43 ortholog has been shown to be ubiquitously expressed in the brain, as well as in the mouse embryonic central nervous system.

Regulations MAP11 has one promoter region upstream of its transcription site, as predicted by Genomatix. This promoter is 657 base pairs long and is located at position 99756182 to 99756838 in the negative strand of chromosome 7. There are several transcription factor binding sites located in this promoter, including binding sites for zinc fingers and Kruppel-like transcription factors. The top 20 transcription binding sites as predicted by the ElDorado from Genomatix is listed in the following table.

Protein

Composition and Domains The human protein MAP11 has an isoelectric point of 8.94. MAP11 also has a glycine-rich region spanning amino acids 54 through 134. Analysis using the SAPS tool from the SDSC Biology Workbench showed this glycine-rich region to not be conserved in terms of specific glycine residue positions, but is well conserved in overall glycine content in mammals and reptiles, although not in bony fishes. C7orf43 is mostly uncharged, and this neutral charge distribution is conserved in mammals and reptiles, but bony fishes have at least one negative charge cluster C7orf43 is predicted to have no signal peptide in its first 70 amino acid residues. However, it is predicted to have a vacuolar targeting motif starting at residue 258 in the human protein. This vacuolar targeting motif is shown to be conserved throughout mammals, reptiles, birds, amphibians, and bony fishes.

Evolutionary history The MAP11 protein has no paralogs in humans. However, C7orf43 orthologs can be found to be highly conserved in mammals, reptiles, and several species of bony fishes. C7orf43 is also conserved in birds, although several bird species lack parts of the N-terminus. No C7orf43 orthologs can be found outside the animal kingdom. The following table lists representative C7orf43 orthologs across multiple animal classes.

Strict orthologs

Distant orthologs

Post-translational modifications C7orf43 has three phosphorylated sites, Ser 517, Thr 541 and, Ser 546. All three sites are relatively well-conserved throughout mammals, reptiles, birds, amphibians, and bony fishes. The protein has no predicted N-myristoylation, as it has no N-terminal glycine. However, C7orf43 is predicted to have one N-acetylation on a serine residue at the N-terminus.

Secondary structure The secondary structure of C7orf43 is yet to be determined. However, C7orf43 is predicted to have no transmembrane domain and to eventually be secreted from the cell. An analysis using the PELE tool from SDSC Biology Workbench predicted mostly beta sheets and random coils that are conserved throughout the strict orthologs. Similarly conserved alpha helix motifs have been predicted, one near the N-terminus and one near the C-terminus.

Clinical significance While no studies have focused on the characterization of C7orf43, several large-scale screenings have revealed information related to C7orf43 function. A study using FLAG affinity purification mass spectrometry (AP-MS) to profile protein interactions in the Hippo signaling pathway identified C7orf43 as one of the interacting proteins. C7orf43 was found to interact with angiomotin-like protein 2 (AMOTL2), also known as Leman Coiled-Coil Protein (LCCP), a regulator of Hippo signaling. AMOTL2 is also known to be an inhibitor of Wnt signaling, a pathway with known associations to cancer development, and to be a factor for angiogenesis, a process essential to tumour maintenance and metastasis. Several studies have linked C7orf43 to carcinomic events. Other studies have also linked C7orf43 to carcinomic events. A large-scale yeast two-hybrid experiment identified C7orf43 to be interacting with transmembrane protein 50A (TMEM50A), also known as cervical cancer gene 9 or small membrane protein 1 (SMP1). While the exact function of TMEM50A is unknown, it has been associated with cervical cancer. C7orf43 has also been identified as a target gene of the transcription factor AP-2 gamma (TFAP2C). TFAP2C has been shown to be involved in the development, differentiation, and oncogenesis of mammary tissues. Specifically, TFAP2C has a role in breast carcinoma through its regulatory effect to ESR1 and ERBB2, both of which are receptors whose aberrations have been associated with breast carcinomas. TFAP2C has also been shown to have an oncogenic role by promotion of cell proliferation and tumour growth in neuroblastoma. Through its location in the q arm of chromosome 7, C7orf43 has been linked to various diseases. Several diseases have been described as having deletions in the q arm of chromosome 7, among them are myeloid disorders, including acute myelogenous leukemia and myelodysplasia.

References

Illustrations

Worked examples

Example 1 — a first encounter with TRAPPC14

Start with the simplest possible case. Write down what TRAPPC14 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 TRAPPC14 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 TRAPPC14 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 TRAPPC14

In research: TRAPPC14 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 TRAPPC14 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: TRAPPC14 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Genes on human chromosome 7, Uncharacterized proteins, so understanding it makes those chapters shorter.
In everyday life: Look for TRAPPC14 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 TRAPPC14 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what TRAPPC14 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 TRAPPC14 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is TRAPPC14 in simple terms?

TRAPPC14 (trafficking protein particle complex subunit 14) also known as MAP11 (microtubule-associated protein 11) is a protein that in human is encoded by the gene TRAPPC14. It was previously referred to by the generic name C7orf43.

Why does TRAPPC14 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 TRAPPC14?

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 TRAPPC14.