2 thoughts on “IN karyloysis, why is the DNA being broken down by endonucleases?”
Endonucleases are activated by increasing concentration of cytosolic Ca2+.
The concentration of cytosolic Ca2+ are 10.000 times lower than extracellular Ca2+ and Ca2+ which remain inside mitochondria and ER.
Cytosolic Ca2+ is maintain by ATP-dependent Ca2-pumps.
During cell injury, such as ischemia, ATP are depleted, which leeds to failure of the ATP-dependent Ca2+ pumps – which leeds to increased cytosolic ATP – which leeds to activation of endonucleases.
Endonucleases cleaves the phosphodiester bond within a polynucleotide chain.
Karyolysis is the process of DNA breakdown in a dying cell due DNase activity. A DNase (short for deoxyribonuclease) is an enzyme that catalyzes the cleavage of phosphodiester bonds in DNA – some are exonucleases cleaving at the ends of DNA molecules and some are endonucleases cleaving anywhere in the DNA chain. The activity of some endo-deoxyribonucleases is activated during cell death – for example by caspases during apoptosis.
Endonucleases are activated by increasing concentration of cytosolic Ca2+.
The concentration of cytosolic Ca2+ are 10.000 times lower than extracellular Ca2+ and Ca2+ which remain inside mitochondria and ER.
Cytosolic Ca2+ is maintain by ATP-dependent Ca2-pumps.
During cell injury, such as ischemia, ATP are depleted, which leeds to failure of the ATP-dependent Ca2+ pumps – which leeds to increased cytosolic ATP – which leeds to activation of endonucleases.
Endonucleases cleaves the phosphodiester bond within a polynucleotide chain.
Karyolysis is the process of DNA breakdown in a dying cell due DNase activity. A DNase (short for deoxyribonuclease) is an enzyme that catalyzes the cleavage of phosphodiester bonds in DNA – some are exonucleases cleaving at the ends of DNA molecules and some are endonucleases cleaving anywhere in the DNA chain. The activity of some endo-deoxyribonucleases is activated during cell death – for example by caspases during apoptosis.