Protection of telomeres protein 1 is a protein that in humans is encoded by the POT1 gene. [5] [6] [7]
Protection of telomeres protein 1 is a protein that in humans is encoded by the POT1 gene. [5] [6] [7]
This gene is a member of the telombin family and encodes a nuclear protein involved in telomere maintenance. Specifically, this protein functions as a member of a multi-protein complex known as shelterin, that binds to the TTAGGG repeats of telomeres, regulating telomere length and protecting chromosome ends from illegitimate recombination, catastrophic chromosome instability, and abnormal chromosome segregation. Alternatively spliced transcript variants have been described. [7]
The absence of POT1 in mouse embryonic fibroblasts and chicken cells leads to a detrimental DNA damage response on telomeres resulting in telomere dysfunction-induced foci (TIFs). POT1 is required for telomere protection because it allows for telomere inhibition of DNA damage response factors. The protein also serves a role in the regulation of telomerase activity on telomeres. In vitro experiments utilizing human POT1 have shown that reduction in POT1 levels result in the elongation of telomeres. [8]
POT1 has been shown to interact with ACD [9] [10] [11] and TINF2. [10] [11] [12]
A telomere is a region of repetitive nucleotide sequences associated with specialized proteins at the ends of linear chromosomes. Telomeres are a widespread genetic feature most commonly found in eukaryotes. In most, if not all species possessing them, they protect the terminal regions of chromosomal DNA from progressive degradation and ensure the integrity of linear chromosomes by preventing DNA repair systems from mistaking the very ends of the DNA strand for a double-strand break.
Telomerase, also called terminal transferase, is a ribonucleoprotein that adds a species-dependent telomere repeat sequence to the 3' end of telomeres. A telomere is a region of repetitive sequences at each end of the chromosomes of most eukaryotes. Telomeres protect the end of the chromosome from DNA damage or from fusion with neighbouring chromosomes. The fruit fly Drosophila melanogaster lacks telomerase, but instead uses retrotransposons to maintain telomeres.
Telomerase reverse transcriptase is a catalytic subunit of the enzyme telomerase, which, together with the telomerase RNA component (TERC), comprises the most important unit of the telomerase complex.
Telomeric repeat-binding factor 2 is a protein that is present at telomeres throughout the cell cycle. It is also known as TERF2, TRF2, and TRBF2, and is encoded in humans by the TERF2 gene. It is a component of the shelterin nucleoprotein complex and a second negative regulator of telomere length, playing a key role in the protective activity of telomeres. It was first reported in 1997 in the lab of Titia de Lange, where a DNA sequence similar, but not identical, to TERF1 was discovered, with respect to the Myb-domain. De Lange isolated the new Myb-containing protein sequence and called it TERF2.
Telomeric repeat-binding factor 1 is a protein that in humans is encoded by the TERF1 gene.
Telomerase RNA component, also known as TR, TER or TERC, is an ncRNA found in eukaryotes that is a component of telomerase, the enzyme used to extend telomeres. TERC serves as a template for telomere replication by telomerase. Telomerase RNAs differ greatly in sequence and structure between vertebrates, ciliates and yeasts, but they share a 5' pseudoknot structure close to the template sequence. The vertebrate telomerase RNAs have a 3' H/ACA snoRNA-like domain.
H/ACA ribonucleoprotein complex subunit 4 is a protein that in humans is encoded by the gene DKC1.
Tankyrase, also known as tankyrase 1, is an enzyme that in humans is encoded by the TNKS gene. It inhibits the binding of TERF1 to telomeric DNA. Tankyrase attracts substantial interest in cancer research through its interaction with AXIN1 and AXIN2, which are negative regulators of pro-oncogenic β-catenin signaling. Importantly, activity in the β-catenin destruction complex can be increased by tankyrase inhibitors and thus such inhibitors are a potential therapeutic option to reduce the growth of β-catenin-dependent cancers.
TERF1-interacting nuclear factor 2 is a protein that in humans is encoded by the TINF2 gene. TINF2 is a component of the shelterin protein complex found at the end of telomeres.
Adrenocortical dysplasia protein homolog is a protein that in humans is encoded by the ACD gene.
Nuclear factor 1 C-type is a protein that in humans is encoded by the NFIC gene.
Telomeric repeat-binding factor 2-interacting protein 1 also known as repressor activator protein 1 (Rap1) is a protein that in humans is encoded by the TERF2IP gene.
40S ribosomal protein S14 is a protein that in humans is encoded by the RPS14 gene.
MAP kinase-interacting serine/threonine-protein kinase 2 is an enzyme that in humans is encoded by the MKNK2 gene.
Forkhead box protein H1 is a protein that in humans is encoded by the FOXH1 gene.
PIN2/TERF1-interacting telomerase inhibitor 1, also known as PINX1, is a human gene. PINX1 is also known as PIN2 interacting protein 1. PINX1 is a telomerase inhibitor and a possible tumor suppressor.
Tankyrase-2 is an enzyme that in humans is encoded by the TNKS2 gene.
Shelterin is a protein complex known to protect telomeres in many eukaryotes from DNA repair mechanisms, as well as to regulate telomerase activity. In mammals and other vertebrates, telomeric DNA consists of repeating double-stranded 5'-TTAGGG-3' (G-strand) sequences along with the 3'-AATCCC-5' (C-strand) complement, ending with a 50-400 nucleotide 3' (G-strand) overhang. Much of the final double-stranded portion of the telomere forms a T-loop (Telomere-loop) that is invaded by the 3' (G-strand) overhang to form a small D-loop (Displacement-loop).
Titia de Lange is the Director of the Anderson Center for Cancer Research, the Leon Hess professor and the head of Laboratory Cell Biology and Genetics at Rockefeller University.
Telomeres, the caps on the ends of eukaryotic chromosomes, play critical roles in cellular aging and cancer. An important facet to how telomeres function in these roles is their involvement in cell cycle regulation.
PDB gallery | |
|---|---|
|
 | This article on a gene on human chromosome 7 is a stub. You can help Wikipedia by expanding it. |
