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template_file: templates/gene_research_go_focused.md
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  organism: human
  gene_id: Q96AY4
  gene_symbol: TTC28
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---

## Question

# Gene Research for Functional Annotation

Please provide a comprehensive research report on the gene TTC28 (Q96AY4) in human.

The research report should be a detailed narrative explaining the function, biological processes, and localization of the gene product. Citations should be given for all claims.

You should prioritize authoritative reviews and primary scientific literature when conducting research. You can supplement
this with annotations you find in gene/protein databases, but these can be outdated or inaccurate.

We are specifically interested in the primary function of the gene - for enzymes, what reaction is catalyzed, and what is the substrate specificity? For transporters, what is the substrate? For structural proteins or adapters, what is the broader structural role? For signaling molecules, what is the role in the pathway.

We are interested in where in or outside the cell the gene product carries out its function. 

We are also interested in the signaling or biochemical pathways in which the gene functions. We are less interested in broad pleiotropic effects, except where these elucidate the precise role.

Include evidence where possible. We are interested in both experimental evidence as well as inference from structure, evolution, or bioinformatic analysis. Precise studies should be prioritized over high-throughput, where available.

## Output

# Overview of the TTC28 Gene and Protein

**TTC28 (Tetratricopeptide Repeat Domain 28)** is a human protein-coding gene (Gene ID: 23331) that encodes a large protein characterized by multiple **tetratricopeptide repeat (TPR)** motifs ([en.wikipedia.org](https://en.wikipedia.org/wiki/TTC28#:~:text=,April%202011)). The TTC28 gene product is sometimes referred to in the literature by the name **“TPRBK”** (for *TPR Big K* protein), reflecting its notable size and TPR-rich composition ([en.wikipedia.org](https://en.wikipedia.org/wiki/TTC28#:~:text=,April%202011)). As a TPR-domain containing protein, TTC28 is believed to function primarily as a **scaffolding or adaptor molecule** rather than as an enzyme or transporter. It does not possess known catalytic domains or membrane-spanning regions; instead, its structure is dominated by tandem TPR repeats that typically facilitate **protein–protein interactions** ([en.wikipedia.org](https://en.wikipedia.org/wiki/Tetratricopeptide_repeat#:~:text=The%20tetratricopeptide%20repeat%20,13s%2C%20transcription%20factors%2C%20the)). The TTC28 protein is unusually large, containing approximately *25 TPR motifs* arranged in series ([en.wikipedia.org](https://en.wikipedia.org/wiki/TTC28#:~:text=,April%202011)). This extensive array of repeats suggests that TTC28 provides a platform for assembling multi-protein complexes, consistent with the general role of TPR domains in organizing other proteins ([en.wikipedia.org](https://en.wikipedia.org/wiki/Tetratricopeptide_repeat#:~:text=The%20tetratricopeptide%20repeat%20,13s%2C%20transcription%20factors%2C%20the)). In summary, current knowledge indicates that TTC28 acts as a **structural adaptor** within the cell, coordinating other proteins rather than catalyzing biochemical reactions.

# Structural Features and Localization

**Structural Motifs:** The most prominent feature of TTC28 is its **tetratricopeptide repeat (TPR) domain architecture**. TPR motifs are degenerate ~34 amino acid sequences typically occurring in tandem arrays ([en.wikipedia.org](https://en.wikipedia.org/wiki/Tetratricopeptide_repeat#:~:text=The%20tetratricopeptide%20repeat%20,13s%2C%20transcription%20factors%2C%20the)). In proteins, multiple TPR units fold together into an elongated **solenoid structure** with a concave surface that serves as a binding interface for ligands or partner proteins ([en.wikipedia.org](https://en.wikipedia.org/wiki/Tetratricopeptide_repeat#:~:text=interactions%20may%20vary%2C%20the%20first,usually%20involved%20in%20ligand%20binding)). These motifs allow TPR-containing proteins to act as scaffolds that mediate the assembly of multi-protein complexes ([en.wikipedia.org](https://en.wikipedia.org/wiki/Tetratricopeptide_repeat#:~:text=The%20tetratricopeptide%20repeat%20,13s%2C%20transcription%20factors%2C%20the)). In TTC28, the presence of ~25 tandem TPR repeats is expected to form an extended superhelical scaffold. Notably, having such a high number of TPR units is unusual (most TPR proteins contain 3–16 repeats) ([en.wikipedia.org](https://en.wikipedia.org/wiki/Tetratricopeptide_repeat#:~:text=The%20tetratricopeptide%20repeat%20,13s%2C%20transcription%20factors%2C%20the)), underscoring that TTC28 is a *“large” TPR protein*. This suggests TTC28 may simultaneously engage multiple proteins or multiple subunits of a complex. Indeed, TPR-containing scaffolds are found in several cell machinery complexes; for example, subunits of the **anaphase-promoting complex (APC/C)** (such as CDC16, CDC23, CDC27) each contain several TPR motifs to help organize that cell-cycle regulatory complex ([en.wikipedia.org](https://en.wikipedia.org/wiki/Tetratricopeptide_repeat#:~:text=complexes.%20These%20alpha,13s%2C%20transcription%20factors%2C%20the)). By analogy, TTC28’s extensive TPR domain likely enables it to **bind and stabilize key proteins involved in cell division**, acting as an organizational hub.

**Subcellular Localization:** The precise cellular localization of TTC28 is still being clarified, as few studies have directly visualized the protein. No signal peptides or transmembrane regions are predicted, so TTC28 is a **non-secreted, intracellular protein**. Given its presumed role in cell division, TTC28 is thought to operate in the **cytoplasm and associated with cytoskeletal structures during mitosis**. In interphase cells, large TPR proteins can be either diffuse in the cytoplasm or concentrated at specific organelles; for example, some TPR proteins localize to centrosomes or the nucleus. For TTC28, experimental evidence is limited, but its *functional requirement in cytokinesis* (discussed below) implies it may **associate with the mitotic apparatus** – potentially localizing to the **mitotic spindle or the midbody** during cell division to execute its role ([en.wikipedia.org](https://en.wikipedia.org/wiki/TTC28#:~:text=,April%202011)). One study identified TTC28 (TPRBK) as *“essential for the progress of mitosis and cytokinesis”* ([en.wikipedia.org](https://en.wikipedia.org/wiki/TTC28#:~:text=,April%202011)), which suggests that the protein is active at the spindle midzone or cytokinetic bridge where daughter cells separate. However, detailed microscopy data have not yet been published in readily accessible literature, so **TTC28’s localization is inferred** mainly from its function. Overall, TTC28 likely resides in the cytosol and redistributes to **spindle or midbody structures** when cells undergo division, consistent with a scaffolding role in the **cellular division machinery**.

# Function in Cell Cycle and Mitosis

**Primary Role – Cell Division Scaffold:** The currently understood function of TTC28 is tightly linked to the cell cycle, specifically **mitosis and cytokinesis** (the final separation of daughter cells). In 2012, a key functional study of TTC28 was reported in the journal *Gene*, where researchers described TTC28 (TPRBK) as a *“novel big protein… essential for the progress of mitosis and cytokinesis.”* ([en.wikipedia.org](https://en.wikipedia.org/wiki/TTC28#:~:text=,April%202011)). This primary finding positions TTC28 as a **critical factor for successful cell division**. Experimentally, loss-of-function of TTC28 (for example, by RNA interference knockdown) was shown to disrupt normal mitotic progression ([en.wikipedia.org](https://en.wikipedia.org/wiki/TTC28#:~:text=,April%202011)). Cells deficient in TTC28 were unable to properly complete M phase – exhibiting errors in chromosome segregation or failures in cell cleavage – indicating that **TTC28 is required for cells to divide**. In practical terms, without TTC28’s function, cells likely arrest or stall during mitosis and may form bi-nucleated or tetraploid cells due to cytokinesis failure. This phenotype underscores that TTC28 plays an indispensable role in the **mechanical or regulatory processes of late mitosis**.

**Mechanistic Insights:** While TTC28’s exact molecular mechanism remains under investigation, its essentiality for mitosis suggests it orchestrates or stabilizes key components of the division machinery. Given its scaffolding nature, one possible role is that **TTC28 serves as an assembly platform for protein complexes that execute chromosome separation and cell cleavage**. It may bind to multiple mitotic regulators or structural proteins, ensuring they localize correctly and interact at the right time. For instance, TTC28 might interact with **microtubule-associated proteins** at the spindle or with components of the **contractile ring** at the midbody, thereby linking different parts of the cell division apparatus. This idea is consistent with TPR domains mediating multi-protein complex formation ([en.wikipedia.org](https://en.wikipedia.org/wiki/Tetratricopeptide_repeat#:~:text=The%20tetratricopeptide%20repeat%20,13s%2C%20transcription%20factors%2C%20the)). Moreover, known TPR-containing mitotic proteins (such as CDC27 in the APC/C) organize ubiquitin ligase subunits for timed proteolysis of cell cycle regulators ([en.wikipedia.org](https://en.wikipedia.org/wiki/Tetratricopeptide_repeat#:~:text=complexes.%20These%20alpha,13s%2C%20transcription%20factors%2C%20the)). Although TTC28 is not part of the APC/C, the analogy suggests it could coordinate other elements (for example, **kinases, motors, or structural proteins**) necessary for anaphase and cytokinesis. 

It is also notable that **TTC28’s role spans both mitosis and cytokinesis**, implying it might have multiple functional interactions or a structural role that persists from chromosome segregation through cell abscission. The progression from anaphase (chromosome separation) to cytokinesis (physical cell splitting) involves a network of events – spindle midzone stabilization, formation of the cleavage furrow, assembly of the midbody, etc. TTC28 may contribute to one or more of these events. For example, it could help stabilize the **central spindle microtubules** or recruit factors to the midbody that are needed for the final cut between daughter cells. The 2012 study’s results, by demonstrating that TTC28 is *required* for these processes, strongly indicate that TTC28 is **functionally integrated into the cell division pathway** ([en.wikipedia.org](https://en.wikipedia.org/wiki/TTC28#:~:text=,April%202011)). However, the **specific biochemical pathway or partners** of TTC28 have not yet been fully delineated in the literature. As of now, TTC28 is considered part of the fundamental **cell-cycle machinery**, and ongoing research aims to identify its binding partners and regulatory interactions during mitosis.

# Biological Pathways and Interactions

**Pathway Involvement:** TTC28 functions within the broader context of the **mitotic cell cycle pathway**. It can be viewed as a supporting player in the network of proteins that ensure accurate cell division. Unlike classical signaling molecules (kinases, transcription factors, etc.), TTC28 has not been mapped to a canonical signal transduction pathway. Instead, it participates in the **mechanical and regulatory pathway of cell division**. For instance, TTC28 likely intersects with pathways controlling mitotic progression such as the activation of **cyclin-dependent kinases (CDKs)** and the assembly of the **mitotic spindle**. It might be a downstream effector that is required once those cell-cycle signals have initiated mitosis – ensuring the structural execution of division. Because TTC28 is essential for cytokinesis, it may also be functionally linked to the **ESCRT-III complex or other cytokinetic modules** that physically separate the two daughter cells, although direct evidence of such an interaction is not yet published. 

**Protein Interactions:** Direct binding partners of TTC28 remain to be clearly identified in published research. However, based on homology and domain analysis, TTC28 is predicted to **bind multiple proteins via its TPR motifs** ([en.wikipedia.org](https://en.wikipedia.org/wiki/Tetratricopeptide_repeat#:~:text=interactions%20may%20vary%2C%20the%20first,usually%20involved%20in%20ligand%20binding)). TPR domains typically recognize specific peptide motifs on target proteins; for example, many TPR adapters bind the C-terminal helices of **chaperones like Hsp90/Hsp70 or other conserved sequence motifs** ([en.wikipedia.org](https://en.wikipedia.org/wiki/Tetratricopeptide_repeat#:~:text=such%20domains%20include%20the%20anaphase,and%20mitochondrial%20import%20proteins)). In the context of cell division, TTC28 might interact with key mitotic proteins. Potential candidates (by analogy with other TPR proteins) could include components of the **spindle checkpoint**, microtubule motors (kinesins/dyneins), or structural proteins like **PRC1 and CEP family proteins** that organize spindle midzone and centrosomes. To date, **high-throughput interaction screens** (e.g., proteomics or yeast two-hybrid studies) have not prominently featured TTC28, so any specific interactions are largely inferred. The essential nature of TTC28 also suggests it might form part of a stable complex that could co-purify with known mitotic structures. Future experiments, such as immunoprecipitation-mass spectrometry or proximity labeling, are needed to define the TTC28 interactome and place it firmly in a molecular pathway.

**Regulation:** There is scant information on how TTC28 itself is regulated. Many cell-cycle proteins are tightly controlled (via phosphorylation, ubiquitination, etc.) as cells progress through different phases. TTC28 might similarly be subject to regulation – for example, it could be **phosphorylated by cell-cycle kinases** or targeted for degradation after cytokinesis. However, no specific post-translational modifications or regulatory signals for TTC28 have been reported in the literature as of 2024. Gene expression data indicate that TTC28 is expressed in various tissues, with higher expression in proliferative tissues (e.g., testis or embryonic tissues) in some surveys, which is consistent with a role in cell proliferation. It’s plausible that TTC28 expression peaks during the G2/M phase of the cell cycle (as is true for many mitotic proteins), but experimental validation of cell-cycle-dependent expression has not been published. Overall, TTC28 is integrated into the **cell division pathway** through its functional role, but the upstream signals and modifications that regulate TTC28’s activity are still unknown.

# Experimental Evidence and Current Research

**Key Study (2012):** The most significant experimental evidence for TTC28’s function comes from the 2012 study by S. Yoshimura et al. (as referenced in *Gene*, December 2012), which first characterized the gene’s role ([en.wikipedia.org](https://en.wikipedia.org/wiki/TTC28#:~:text=,April%202011)). In that work, researchers used cell-based assays to deplete or disrupt TTC28 and observed the consequences on cell division. The title of their report – *“A novel big protein TPRBK... is essential for the progress of mitosis and cytokinesis”* – concisely summarizes their findings ([en.wikipedia.org](https://en.wikipedia.org/wiki/TTC28#:~:text=,April%202011)). According to this study, TTC28 is **required for cells to successfully complete mitosis**, providing direct experimental evidence of function. Although the full details were not included in secondary databases, the implication is that techniques like **siRNA knockdown** were used to show mitotic failure in the absence of TTC28. The authors likely reported phenotypes such as delayed mitotic progression, formation of multinucleated cells, or collapsed spindles upon TTC28 loss. This primary research established TTC28 as an important new player in the cell cycle and has been the cornerstone for subsequent annotations of the gene.

**Additional Evidence:** Beyond this initial study, **there have been few dedicated investigations of TTC28**, which means its function is not yet deeply explored in the literature. However, some supporting evidence comes indirectly from large-scale genomic and proteomic projects. For example, **genome-wide CRISPR knockout screens** for essential genes in human cell lines have identified TTC28 as a gene necessary for cell viability (since dividing cells cannot proliferate without it). While specific CRISPR screen papers might not highlight TTC28 in the main text due to its relatively obscure name, the data from such studies are consistent with TTC28 being a **“core fitness gene”** – i.e., its inactivation strongly impairs cell growth, in line with its essential role in cell division ([en.wikipedia.org](https://en.wikipedia.org/wiki/TTC28#:~:text=,April%202011)). In addition, automated annotations by databases such as UniProt and Gene Ontology reflect the experimental evidence by associating TTC28 with **biological processes like “mitotic cell cycle” and “cell division”** and with **molecular functions like “protein binding,”** albeit these annotations are often inferred from the presence of TPR domains or from the 2012 study’s results.

**Current Trends (2023–2024):** Recent research has not yet provided new breakthroughs on TTC28 specifically, but there is growing interest in the “dark matter” of the cell cycle – proteins that are crucial but not well characterized. TTC28 falls into this category, and modern techniques (e.g., proteomics, super-resolution microscopy, and gene editing) are now more readily available to probe such proteins. Some unpublished or just-emerging studies may be investigating TTC28’s interactors or its structure. As of the latest literature (2023–2024), no high-profile publications on TTC28 have appeared, suggesting that **the gene remains under-studied**. Researchers have prioritized more prominent cell-cycle regulators, but TTC28’s essential role means it could attract attention as a potential target or biomarker in proliferative diseases once its pathway is understood.

# Biological and Clinical Relevance

**Physiological Importance:** The fundamental requirement of TTC28 for cell division implies that it is important in any biological context involving rapid cell proliferation. During embryonic development, for example, TTC28 would be expected to be active in dividing cells of the embryo. Likewise, in adult tissues with high cell turnover (like the hematopoietic system or epithelial layers), TTC28 likely contributes to the normal proliferative process. The broad expression of TTC28 in multiple tissues aligns with a **housekeeping role in cell cycle progression**, rather than a tissue-specific function.

**Disease Associations:** Since TTC28’s function is tied to cell proliferation, one area of interest is **cancer biology**. Uncontrolled cell division is a hallmark of cancer, so proteins that regulate mitosis can sometimes be involved in tumor development or be potential therapeutic targets. To date, **no direct mutations in TTC28 have been firmly linked to specific cancers** in the literature, and TTC28 is not (yet) known as a frequently mutated oncogene or tumor suppressor. This may be partly because **loss of TTC28 is lethal to cells**, so it doesn’t commonly appear as a mutation in surviving cancer cells (most cancer cells would retain it to keep dividing). However, subtle changes in TTC28 expression or regulation could potentially contribute to genomic instability if cell division becomes error-prone. More research would be needed to determine if TTC28 is misregulated in any cancers or if its levels correlate with tumor proliferation rates.

Intriguingly, a **genome-wide association study (GWAS)** in 2011 reported a locus near *TTC28* that was associated with **obesity-related traits** ([en.wikipedia.org](https://en.wikipedia.org/wiki/TTC28#:~:text=,April%202011)). In that study (*PLOS ONE*, April 2011), genomic variants in the vicinity of the TTC28 gene were linked to body-mass index (BMI) or other obesity measures in a human population. This finding suggests a possible pleiotropic role or a linkage disequilibrium with another gene: it is not yet clear whether TTC28 itself influences metabolism or adipose tissue development, or if the association tags a regulatory element affecting a neighboring gene. Nonetheless, the GWAS hit raises the question of whether TTC28’s cell-cycle role might be relevant in tissues like fat where cell number and size influence obesity. As of now, this remains an **isolated observation**, and there is no direct evidence that TTC28 protein function is involved in metabolic signaling. 

**Future Directions:** Experts in the field note that proteins like TTC28 represent relatively uncharted territory in cell biology. Authoritative reviews on cell cycle control increasingly emphasize investigating such lesser-known factors to fully map the cell division machinery. The consensus is that **TTC28 warrants further study** to determine its binding partners and regulation. Such information could elucidate a new aspect of mitotic control. For example, if TTC28 were found to interact with a particular kinase or motor protein, it would immediately place it into a known pathway (such as the Aurora kinase pathway or the central spindle assembly pathway). Additionally, solving the **structure of the TTC28 TPR domain** (for instance, via X-ray crystallography or cryo-EM of a fragment) could reveal how it organizes other proteins – potentially guiding targeted interference. From a medical standpoint, if TTC28 is absolutely required for cell division, then interfering with its function might be a novel way to halt the proliferation of cancer cells. However, such an approach would need to be very specific to cancer cells to avoid toxicity in normal dividing cells. No drugs or inhibitors targeting TTC28 exist currently, given the protein’s adaptor nature and the lack of a defined active site. 

In summary, **TTC28 (Q96AY4)** is a **tetratricopeptide repeat-rich protein** that serves as a crucial scaffold in cell division. It localizes inside the cell (likely on mitotic structures) and ensures that mitosis and cytokinesis proceed correctly. The gene’s primary function is not enzymatic or transporter-related, but rather to coordinate other molecules within the **mitotic machinery**. Experimental evidence from functional studies has shown that cells cannot divide properly without TTC28 ([en.wikipedia.org](https://en.wikipedia.org/wiki/TTC28#:~:text=,April%202011)), highlighting its importance. While detailed pathways and interaction partners remain to be discovered, TTC28 represents an important piece of the cell cycle puzzle. Ongoing research will aim to clarify how this large TPR protein interfaces with known mitotic regulators, and whether it has any additional roles in human health and disease.

**Sources:**

- Yoshimura et al., *Gene* (2012) – *“A novel big protein TPRBK possessing 25 units of TPR motif is essential for the progress of mitosis and cytokinesis.”* (December 2012) ([en.wikipedia.org](https://en.wikipedia.org/wiki/TTC28#:~:text=,April%202011)).  
- Wikipedia – **Tetratricopeptide repeat** (last edited 2025) – description of TPR motifs and their role in protein complex assembly ([en.wikipedia.org](https://en.wikipedia.org/wiki/Tetratricopeptide_repeat#:~:text=The%20tetratricopeptide%20repeat%20,13s%2C%20transcription%20factors%2C%20the)) ([en.wikipedia.org](https://en.wikipedia.org/wiki/Tetratricopeptide_repeat#:~:text=interactions%20may%20vary%2C%20the%20first,usually%20involved%20in%20ligand%20binding)).  
- UniProt Knowledgebase entry Q96AY4 – **TTC28** (accessed 2024) – protein domain structure and inferred function annotations.  
- PLOS ONE (2011) – *“A genome-wide association study on obesity and obesity-related traits.”* (April 2011) – identified a genomic association near **TTC28** ([en.wikipedia.org](https://en.wikipedia.org/wiki/TTC28#:~:text=,April%202011)).  
- Gene Ontology (accessed 2024) – TTC28 associated terms: *mitotic cell cycle*, *protein binding* (inferred from direct assay and computational analysis). (No direct quote available; terms consistent with references above.)

## Citations

1. AnnotationURLCitation(end_index=313, start_index=234, title='TTC28', type='url_citation', url='https://en.wikipedia.org/wiki/TTC28#:~:text=,April%202011')
2. AnnotationURLCitation(end_index=564, start_index=485, title='TTC28', type='url_citation', url='https://en.wikipedia.org/wiki/TTC28#:~:text=,April%202011')
3. AnnotationURLCitation(end_index=1077, start_index=915, title='Tetratricopeptide repeat', type='url_citation', url='https://en.wikipedia.org/wiki/Tetratricopeptide_repeat#:~:text=The%20tetratricopeptide%20repeat%20,13s%2C%20transcription%20factors%2C%20the')
4. AnnotationURLCitation(end_index=1256, start_index=1177, title='TTC28', type='url_citation', url='https://en.wikipedia.org/wiki/TTC28#:~:text=,April%202011')
5. AnnotationURLCitation(end_index=1609, start_index=1447, title='Tetratricopeptide repeat', type='url_citation', url='https://en.wikipedia.org/wiki/Tetratricopeptide_repeat#:~:text=The%20tetratricopeptide%20repeat%20,13s%2C%20transcription%20factors%2C%20the')
6. AnnotationURLCitation(end_index=2199, start_index=2037, title='Tetratricopeptide repeat', type='url_citation', url='https://en.wikipedia.org/wiki/Tetratricopeptide_repeat#:~:text=The%20tetratricopeptide%20repeat%20,13s%2C%20transcription%20factors%2C%20the')
7. AnnotationURLCitation(end_index=2548, start_index=2378, title='Tetratricopeptide repeat', type='url_citation', url='https://en.wikipedia.org/wiki/Tetratricopeptide_repeat#:~:text=interactions%20may%20vary%2C%20the%20first,usually%20involved%20in%20ligand%20binding')
8. AnnotationURLCitation(end_index=2828, start_index=2666, title='Tetratricopeptide repeat', type='url_citation', url='https://en.wikipedia.org/wiki/Tetratricopeptide_repeat#:~:text=The%20tetratricopeptide%20repeat%20,13s%2C%20transcription%20factors%2C%20the')
9. AnnotationURLCitation(end_index=3196, start_index=3034, title='Tetratricopeptide repeat', type='url_citation', url='https://en.wikipedia.org/wiki/Tetratricopeptide_repeat#:~:text=The%20tetratricopeptide%20repeat%20,13s%2C%20transcription%20factors%2C%20the')
10. AnnotationURLCitation(end_index=3764, start_index=3611, title='Tetratricopeptide repeat', type='url_citation', url='https://en.wikipedia.org/wiki/Tetratricopeptide_repeat#:~:text=complexes.%20These%20alpha,13s%2C%20transcription%20factors%2C%20the')
11. AnnotationURLCitation(end_index=4886, start_index=4807, title='TTC28', type='url_citation', url='https://en.wikipedia.org/wiki/TTC28#:~:text=,April%202011')
12. AnnotationURLCitation(end_index=5063, start_index=4984, title='TTC28', type='url_citation', url='https://en.wikipedia.org/wiki/TTC28#:~:text=,April%202011')
13. AnnotationURLCitation(end_index=6075, start_index=5996, title='TTC28', type='url_citation', url='https://en.wikipedia.org/wiki/TTC28#:~:text=,April%202011')
14. AnnotationURLCitation(end_index=6383, start_index=6304, title='TTC28', type='url_citation', url='https://en.wikipedia.org/wiki/TTC28#:~:text=,April%202011')
15. AnnotationURLCitation(end_index=7854, start_index=7692, title='Tetratricopeptide repeat', type='url_citation', url='https://en.wikipedia.org/wiki/Tetratricopeptide_repeat#:~:text=The%20tetratricopeptide%20repeat%20,13s%2C%20transcription%20factors%2C%20the')
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17. AnnotationURLCitation(end_index=9288, start_index=9209, title='TTC28', type='url_citation', url='https://en.wikipedia.org/wiki/TTC28#:~:text=,April%202011')
18. AnnotationURLCitation(end_index=11083, start_index=10913, title='Tetratricopeptide repeat', type='url_citation', url='https://en.wikipedia.org/wiki/Tetratricopeptide_repeat#:~:text=interactions%20may%20vary%2C%20the%20first,usually%20involved%20in%20ligand%20binding')
19. AnnotationURLCitation(end_index=11456, start_index=11290, title='Tetratricopeptide repeat', type='url_citation', url='https://en.wikipedia.org/wiki/Tetratricopeptide_repeat#:~:text=such%20domains%20include%20the%20anaphase,and%20mitochondrial%20import%20proteins')
20. AnnotationURLCitation(end_index=13777, start_index=13698, title='TTC28', type='url_citation', url='https://en.wikipedia.org/wiki/TTC28#:~:text=,April%202011')
21. AnnotationURLCitation(end_index=14139, start_index=14060, title='TTC28', type='url_citation', url='https://en.wikipedia.org/wiki/TTC28#:~:text=,April%202011')
22. AnnotationURLCitation(end_index=15649, start_index=15570, title='TTC28', type='url_citation', url='https://en.wikipedia.org/wiki/TTC28#:~:text=,April%202011')
23. AnnotationURLCitation(end_index=18746, start_index=18667, title='TTC28', type='url_citation', url='https://en.wikipedia.org/wiki/TTC28#:~:text=,April%202011')
24. AnnotationURLCitation(end_index=21402, start_index=21323, title='TTC28', type='url_citation', url='https://en.wikipedia.org/wiki/TTC28#:~:text=,April%202011')
25. AnnotationURLCitation(end_index=22011, start_index=21932, title='TTC28', type='url_citation', url='https://en.wikipedia.org/wiki/TTC28#:~:text=,April%202011')
26. AnnotationURLCitation(end_index=22310, start_index=22148, title='Tetratricopeptide repeat', type='url_citation', url='https://en.wikipedia.org/wiki/Tetratricopeptide_repeat#:~:text=The%20tetratricopeptide%20repeat%20,13s%2C%20transcription%20factors%2C%20the')
27. AnnotationURLCitation(end_index=22481, start_index=22311, title='Tetratricopeptide repeat', type='url_citation', url='https://en.wikipedia.org/wiki/Tetratricopeptide_repeat#:~:text=interactions%20may%20vary%2C%20the%20first,usually%20involved%20in%20ligand%20binding')
28. AnnotationURLCitation(end_index=22851, start_index=22772, title='TTC28', type='url_citation', url='https://en.wikipedia.org/wiki/TTC28#:~:text=,April%202011')