What is a Ribonuclease?

Ribonuclease (RNase) is an enzyme that splits ribonucleic acid (RNA) in certain areas, and is produced in the lysosomes of cells. RNA is found in a cell's cytoplasm and synthesizes protein. Lysosomes are particles in the cytoplasm, a jelly-like substance that surrounds the cells nucleus. There are two forms of ribonuclease, exoribonucleases and endoribonucleases.

Deoxyribonucleic acid (DNA) is present in all cells and provides the genetic blueprint for all living beings, and most of the viruses. While RNA is also present in all cells, it is responsible for the production of certain proteins, and constitutes the genetic material for some viruses, like influenza. Influenza is caused by a highly contagious RNA virus that affects the respiratory system, and sufferers often show symptoms of high fever, nausea, coughing, and sneezing.

DNA and RNA are both made up of four bases. Both contain adenine, guanine, and cytosine, but only DNA contains thymine — and only RNA has uracil. Adenine bonds with uracil and thymine, whereas guanine bonds with cytosine, thus creating the characteristic base pairs that form the molecular strands. There is another major difference between RNA and DNA, DNA is double-stranded and RNA is single-stranded.

Endoribonucleases are ribonuclease endonucleases, which are enzymes that separate phosphodiester bonds that occur within molecular chains. Phosphodiester bonds occur between phosphates and carbohydrates, and are very important to the structure of RNA. Exoribonucleases are ribonuclease exonucleases that are responsible for degrading RNA through the removal of nucleotides towards the ends of the molecule strands. Nucleotides are molecules that, when joined together, form RNA or DNA. Exoribonuclease degrades all forms of RNA — transfer RNA, messenger RNA, ribosomal RNA, and MiRNA.

Transfer RNA carries amino acids to the ribosome, a particle in the cytoplasm. Ribosomal RNA molecules actually are components of the ribosome itself. Messenger RNA is responsible for carrying one or more gene codes from the DNA to the ribosomes or organelles, a specialized structure in the cytoplasm, so that the code can be translated into the appropriate protein. MiRNA, or MicroRNA, bind to sections or messenger RNA, and silence the sequence it binds with.

The degradation of RNA within a cell not only helps with cleaning up bits of RNA that are no longer needed, but it also aids in protecting the body from viruses. RNA has a short lifespan because of the maturation and degradation caused by the ribonuclease. Maturation occurs when superfluous bits of code are systematically eliminated as new RNA molecules are produced, and older ones are destroyed. Ribonuclease also degrades virus RNA. There are a variety of ribonucleases that are being studied and classified, and each has its own particular role in the maintenance and production of cells' RNA.