Protection of telomeres protein 1 is a
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...
that in humans is encoded by the ''POT1''
gene
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...
.
Function
This gene is a member of the telombin family and encodes a nuclear protein involved in
telomere
A telomere (; ) is a region of repetitive nucleotide sequences associated with specialized proteins at the ends of linear chromosomes. Although there are different architectures, telomeres, in a broad sense, are a widespread genetic feature mos ...
maintenance. Specifically, this protein functions as a member of a multi-protein complex known as
shelterin
Shelterin (also called telosome) 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 doubl ...
, 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.
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
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 euka ...
activity on telomeres. In vitro experiments utilizing human POT1 have shown that reduction in POT1 levels result in the elongation of telomeres.
Interactions
POT1 has been shown to
interact
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with
ACD and
TINF2
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.
Interactions
TINF2 has been shown to interact with ACD, POT1 ...
.
Pathology
*Increased transcriptional expression of this gene is associated with stomach carcinogenesis and its progression.
*Mutations in this gene have also been associated to the acquisition of the malignant features of chronic lymphocytic leukemia
Chronic lymphocytic leukemia (CLL) is a type of cancer in which the bone marrow makes too many lymphocytes (a type of white blood cell). Early on, there are typically no symptoms. Later, non-painful lymph node swelling, feeling tired, fever, nigh ...
.melanoma
Melanoma, also redundantly known as malignant melanoma, is a type of skin cancer that develops from the pigment-producing cells known as melanocytes. Melanomas typically occur in the skin, but may rarely occur in the mouth, intestines, or eye ( ...
glioma
A glioma is a type of tumor that starts in the glial cells of the brain or the spine. Gliomas comprise about 30 percent of all brain tumors and central nervous system tumours, and 80 percent of all malignant brain tumours.
Signs and symptoms
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References
Further reading
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External links
PDBe-KB
provides an overview of all the structure information available in the PDB for Human Protection of telomeres protein 1 (POT1)
Telomere-binding proteins
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