telomerase catalytic core complex

Definition

Target type: cellularcomponent

The minimal catalytic core of telomerase is a ribonucleoprotein complex composed of a catalytic reverse transcriptase subunit and an RNA subunit that provides the template for telomeric DNA addition. [GOC:BHF-UCL, PMID:11884619, PMID:1808260]

The telomerase catalytic core complex is a ribonucleoprotein complex responsible for adding repetitive DNA sequences to the ends of chromosomes, known as telomeres. This complex is essential for maintaining the integrity of chromosomes and preventing cellular senescence. The core complex consists of two main components:

1. **Telomerase Reverse Transcriptase (TERT):** This is the catalytic subunit of the complex, possessing reverse transcriptase activity, allowing it to synthesize DNA using an RNA template. TERT binds to the telomerase RNA component (TERC) and possesses a variety of domains, including:

* **RNA-binding domain (RBD):** Binds to the template region of TERC.
* **Reverse transcriptase (RT) domain:** Catalyzes the synthesis of DNA from the RNA template.
* **Extension domain:** Contributes to the extension of the 3' end of telomeric DNA.
* **C-terminal domain (CTD):** Interacts with various proteins, including TERC, and regulates telomerase activity.

2. **Telomerase RNA Component (TERC):** This is a non-coding RNA molecule that serves as the template for telomere synthesis. TERC contains a template region complementary to the telomeric repeat sequence (TTAGGG) and several other regions involved in its function and stability.

The telomerase core complex functions through a series of steps:

1. **TERC Binding:** TERT binds to TERC, forming the core complex.
2. **Template Recognition:** TERT recognizes the template region within TERC.
3. **DNA Synthesis:** Using the RNA template from TERC, TERT synthesizes DNA, adding the telomeric repeat sequence (TTAGGG) to the 3' end of the chromosome.
4. **Translocation:** After each repeat addition, TERT translocates to the newly synthesized DNA, preparing for the addition of the next repeat.

The telomerase catalytic core complex is tightly regulated and its activity is influenced by various factors, including cell type, developmental stage, and cellular stress. Dysregulation of telomerase activity has been implicated in cancer development and aging.

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Proteins (1)

Compounds (28)